[Federal Register Volume 69, Number 65 (Monday, April 5, 2004)]
[Proposed Rules]
[Pages 17774-17842]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-7033]



[[Page 17773]]

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Part III





Department of Labor





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Occupational Safety and Health Administration



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29 CFR Part 1910



Electrical Standard; Proposed Rule

  Federal Register / Vol. 69, No. 65 / Monday, April 5, 2004 / Proposed 
Rules  

[[Page 17774]]


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DEPARTMENT OF LABOR

Occupational Safety and Health Administration

29 CFR Part 1910

[Docket No. S-108C]
RIN 1218-AB95


Electrical Standard

AGENCY: Occupational Safety and Health Administration, Labor.

ACTION: Proposed rule.

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SUMMARY: The Occupational Safety and Health Administration (OSHA) is 
proposing to revise the general industry electrical installation 
standard found in Subpart S of 29 CFR Part 1910. The Agency has 
determined that electrical hazards in the workplace pose a significant 
risk of injury or death to employees, and that the requirements in the 
revised standard, which draw heavily from the 2000 edition of the 
National Fire Protection Association's (NFPA) Electrical Safety 
Requirements for Employee Workplaces (NFPA 70E), and the 2002 edition 
of the National Electrical Code (NEC), are reasonably necessary to 
provide protection from these hazards. This proposed rule focuses on 
safety in the design and installation of electric equipment in the 
workplace. This revision will provide the first update of the 
installation requirements in the general industry electrical 
installation standard since 1981.
    OSHA is also proposing to replace the reference to the 1971 
National Electrical Code in the mandatory appendix to the powered 
platform standard with a reference to OSHA's electrical installation 
standard.

DATES: Submit written hearing requests and comments regarding this 
proposal, including comments on the information-collection 
determination described in Section XI. of the preamble (OMB Review 
under the Paperwork Reduction Act of 1995), by the following dates:
    Hard Copy: Your hearing requests and comments must be submitted 
(postmarked or sent) by June 4, 2004.
    Facsimile and electronic transmission: Your hearing requests and 
comments must be sent by June 4, 2004.
    Please see the section entitled SUPPLEMENTARY INFORMATION for 
additional information on submitting written comments and hearing 
requests.

ADDRESSES: Regular mail, express delivery, hand-delivery, and messenger 
service: Submit three copies of hearing requests, comments, and 
attachments to the OSHA Docket Office, Docket No. S-108C, Room N-2625, 
U.S. Department of Labor, 200 Constitution Avenue, NW, Washington, DC 
20210; telephone (202) 693-2350. OSHA Docket Office and Department of 
Labor hours of operation are 8:15 a.m. to 4:45 p.m., e.s.t.
    Please note that security-related problems may result in 
significant delays in receiving comments and other materials by regular 
mail. Telephone the OSHA Docket Office at (202) 693-2350 for 
information regarding security procedures concerning delivery of 
materials by express delivery, hand delivery, and messenger service.
    Facsimile: Transmit hearing requests and comments (including 
attachments) consisting of 10 or fewer pages by facsimile to the OSHA 
Docket Office at (202) 693-1648. You must include the docket number of 
this notice, Docket No. S-108C, in your comments.
    Electronic: Submit comments electronically through the Internet at 
http://ecomments.osha.gov.
    All comments and submissions will be available for inspection and 
copying in the OSHA Docket Office at the address above. Most comments 
and submissions will be posted on OSHA's Web page (http://www.osha.gov). Contact the OSHA Docket Office at (202) 693-2350 for 
information about materials not available on the OSHA Web page and for 
assistance in using this Web page to locate docket submissions. Because 
comments sent to the docket or to OSHA's Web page are available for 
public inspection, the Agency cautions interested parties against 
including in these comments personal information such as social 
security numbers and birth dates.

FOR FURTHER INFORMATION CONTACT: For general information and press 
inquiries, contact Mr. George Shaw, Office of Communications, Room N-
3647, OSHA, U.S. Department of Labor, 200 Constitution Avenue, NW., 
Washington, DC 20210; telephone (202) 693-1999. For technical 
inquiries, contact Ms. Belinda Cannon, Directorate of Standards and 
Guidance, Room N-3609, OSHA, U.S. Department of Labor, 200 Constitution 
Avenue, NW., Washington, DC 20210; telephone (202) 693-2083.
    For additional copies of this Federal Register notice, contact 
OSHA, Office of Publications, U.S. Department of Labor, Room N-3101, 
200 Constitution Avenue, NW., Washington, DC 20210; telephone (202) 
693-1888. Electronic copies of this Federal Register notice, as well as 
news releases and other relevant documents, are available at OSHA's web 
page on the Internet at http://www.osha.gov.

SUPPLEMENTARY INFORMATION:

I. Introduction

    This proposed rule would revise OSHA's existing standard for 
electrical installations, which is contained in Sec. Sec.  1910.302 
through 1910.308 of Subpart S, with relevant definitions in Sec.  
1910.399. It would apply, as the existing standard does, to employers 
in general industry and in maritime employment.
    OSHA undertook the project to revise Subpart S for two major 
reasons. First, the Agency wanted the rule to reflect the most current 
practice and technology in the industry. The current rule is based on a 
national consensus standard, the 1979 edition of Part I of NFPA 70E, 
entitled Standard for Electrical Safety Requirements for Employee 
Workplaces. That consensus standard has been updated several times 
since OSHA last revised its electrical installation requirements in 
1981. The proposed rule being published today relies heavily on the 
2000 edition of NFPA 70E. Second, in proposing this rule, OSHA is 
responding to requests from stakeholders that the Agency revise Subpart 
S so that it conforms with the most recent editions of NFPA 70E and the 
National Electrical Code.\1\ These stakeholders argued that interested 
members of the public have had substantial input into the content of 
NFPA 70E, and that industry is complying with that standard in its 
current form. The revised regulation will be more flexible and 
efficient for stakeholders and small businesses, while maintaining 
needed protections for workers.
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    \1\ See, for example, letters from: Judith Gorman, Managing 
Director of the Institute of Electrical and Electronic Engineers; 
George D. Miller, President and Chief Executive Officer of the 
National Fire Protection Association; Frank K. Kitzantides, Vice 
President of Engineering at the National Electrical Manufacturers 
Association; and Kari P. Barrett, Director of Regulatory and 
Technical Affairs, Plant Operations, at the American Chemistry 
Council.
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    OSHA's existing electrical standard in Sec. Sec.  1910.302 through 
1910.308 is based on the 1979 edition of NFPA 70E, which is a national 
consensus standard developed by a cross section of industry, labor, and 
other allied interests. Consensus standards like the National 
Electrical Code (NEC) and NFPA 70E provide nationally recognized safe 
electrical installation requirements. Additionally, the consensus 
process used in developing NFPA 70E, Part 1 of which is based on the 
NEC, ensures that requirements contained in that standard are current 
and at the forefront of electrical safety technology. Because the 
primary objective of this revision of Subpart S is to update the 
standard to recognize, and

[[Page 17775]]

in some cases require, the most current electrical safety technology, 
OSHA believes that the 2000 edition of NFPA 70E should be the 
foundation of the proposal.
    The remainder of the preamble discusses the background of the 
proposal; the history of Subpart S and the development of this 
proposal; the statutory considerations; a summary and explanation of 
the proposed standard; the Preliminary Economic and Regulatory 
Flexibility Analysis; the information collections associated with the 
rule; and other miscellaneous topics. The outline of the preamble is as 
follows:

I. Introduction
II. Background
III. History of the Rule
IV. Legal Authority
V. Summary and Explanation of the Proposed Rule
VI. Preliminary Economic and Regulatory Screening Analysis
VII. State Plan Standards
VIII. Environmental Impact Analysis
IX. Unfunded Mandates
X. Federalism
XI. OMB Review under the Paperwork Reduction Act of 1995
XII. Public Participation
XIII. List of Subjects
XIV. Authority and Signature

II. Background

A. Hazards Associated With Electricity

    Electricity is widely recognized as a serious workplace hazard, 
exposing employees to electric shock, burns, fires, and explosions. 
According to the Bureau of Labor Statistics, 289 employees were killed 
by contact with electric current in 2002.\2\ Other employees have been 
killed or injured in fires and explosions caused by electricity.
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    \2\ ``2002 Census of Fatal Occupational Injuries,'' Table A-9, 
Bureau of Labor Statistics, http://www.bls.gov/iif/oshwc/cfoi/cftb0163.pdf.
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    It is well known that the human body will conduct electricity. If 
direct body contact is made with an electrically energized part while a 
similar contact is made simultaneously with another conductive surface 
that is maintained at a different electrical potential, a current will 
flow, entering the body at one contact point, traversing the body, and 
then exiting at the other contact point, usually the ground. Each year 
many workers suffer pain, injuries and death from such electric shocks.
    Burns suffered in electrical accidents can be very serious. These 
burns may be of three basic types: electrical burns, arc burns, and 
thermal contact burns. Electrical burns are the result of the electric 
current flowing in the tissues, and may be either skin deep or may 
affect deeper layers (such as muscles and bones) or both. Tissue damage 
is caused by the heat generated from the current flow; if the energy 
delivered by the electric shock is high, the body cannot dissipate the 
heat and the tissue is burned. Typically, such electrical burns are 
slow to heal. Arc burns are the result of high temperatures produced by 
electric arcs or by explosions close to the body. If the current 
involved is great enough, these arcs can cause injury or can start a 
fire. Fires can also be created by overheating equipment or by 
conductors carrying too much current. Extremely high-energy arcs can 
damage equipment, causing fragmented metal to fly in all directions. In 
atmospheres which contain explosive gases or vapors or combustible 
dusts, even low-energy arcs can cause violent explosions. These burns 
are similar to burns and blisters produced by any high temperature 
source. Finally, thermal contact burns are those normally experienced 
from the skin contacting hot surfaces of overheated electric 
conductors, conduits, or other energized equipment. All types of burns 
may be produced simultaneously.
    Current through the body, even at levels as low as 3 milliamperes, 
can also cause injuries of an indirect or secondary nature in which 
involuntary muscular reaction from the electric shock can cause 
bruises, bone fractures and even death resulting from collisions or 
falls.

B. Nature of Electrical Accidents

    Electrical accidents, when initially studied, often appear to be 
caused by circumstances that are varied and peculiar to the particular 
incidents involved. However, further consideration usually reveals the 
underlying cause to be a combination of three possible factors: work 
involving unsafe equipment and installations; workplaces made unsafe by 
the environment; and unsafe work performance (unsafe acts). The first 
two factors are sometimes combined and simply referred to as unsafe 
conditions. Thus, electrical accidents can be generally considered as 
being caused by unsafe conditions, unsafe acts, or, in what is usually 
the case, combinations of the two. It should also be noted that 
inadequate maintenance can cause equipment or installations which were 
originally considered safe to deteriorate, resulting in an unsafe 
condition.
    Some unsafe electric equipment and installations can be identified, 
for example, by the presence of faulty insulation, improper grounding, 
loose connections, defective parts, ground faults in equipment, 
unguarded live parts, and underrated equipment. The environment can 
also be a contributory factor to electrical accidents in a number of 
ways. Environments containing flammable vapors, liquids or gases; areas 
containing corrosive atmospheres; and wet and damp locations are some 
unsafe environments affecting electrical safety. Finally, unsafe acts 
include the failure to deenergize electric equipment when it is being 
repaired or inspected, the use of obviously defective and unsafe tools, 
or the use of tools or equipment too close to energized parts.

C. Protective Measures

    There are various general ways of protecting employees from the 
hazards of electric shock, including insulation and guarding of live 
parts. Insulation provides an electrical barrier to the flow of 
current. To be effective, the insulation must be appropriate for the 
voltage, and the insulating material must be undamaged, clean, and dry. 
Guarding prevents the employee from coming too close to energized 
parts. It can be in the form of a physical barricade, or it can be 
provided by installing the live parts out of reach from the working 
surface. (This technique is known as ``guarding by location.'')
    Grounding is another method of protecting employees from electric 
shock; however, it is normally a secondary protective measure. To keep 
guards or enclosures at a common potential with earth, they are 
connected, by means of a grounding conductor, to ground. In addition, 
grounding provides a path of low impedance and of ample capacity back 
to the source to pass enough current to operate the overcurrent devices 
in the circuit. If a live part accidentally comes in contact with a 
grounded enclosure, current flow is directed back to earth, and the 
circuit protective devices (for example, fuses and circuit breakers) 
can interrupt the circuit.
    If it draws too much current, electric equipment can overheat, 
which can result in fires.\3\ Protecting electric equipment from 
overcurrent helps prevent this from happening.
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    \3\ Overheating can also lead to electric shock hazards if the 
insulation protecting a conductor melts.
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    Designing and installing equipment to protect against dangerous 
arcing and overheating is also important in preventing unsafe 
conditions that can lead to fires, high energy electric arcs, and 
explosions. Employers and employees cannot usually detect

[[Page 17776]]

improperly designed or rated equipment. Thus, OSHA relies on third-
party testing and certification of electric equipment to ensure proper 
electrical design. This helps ensure, for example, that equipment will 
not overheat during normal operation and that equipment designed for 
use in a hazardous location will not cause a fire or explosion. It also 
helps ensure that equipment is appropriately rated and marked, allowing 
employees designing electrical installations and installing electric 
equipment to select equipment and size conductors in accordance with 
those ratings.\4\ Many of the requirements in OSHA's electrical 
standards in turn depend on accurate ratings on equipment.
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    \4\ Electric equipment is typically rated for use with certain 
voltages and current. For example, an electric hair dryer might be 
rated at 125 volts, 1875 watts. The voltage rating indicates the 
maximum voltage for which the equipment is rated. The wattage rating 
indicates how much power the equipment will draw when connected to a 
circuit at the maximum voltage. The current drawn by the equipment 
is the wattage rating divided by the voltage rating. Thus, the 
circuit voltage (120 volts, nominal) is less than the maximum rated 
voltage of the hair dryer (125 volts), and the circuit is rated for 
the current the equipment will draw (1875 watts/125 volts = 15 
amperes). Thus, the hair dryer would be suitable for use on a 120-
volt circuit capable of safely carrying 15 amperes.
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    These protective measures help ensure the safe installation of 
electric equipment and are prescribed by the requirements presently 
contained in 29 CFR Part 1910, Subpart S. Addressing common unsafe 
conditions, these rules cover such safety considerations as guarding 
and insulation of live parts, grounding of equipment enclosures, and 
protection of circuits from overcurrent. This rulemaking would update 
those requirements to make them consistent with the latest edition of 
NFPA 70E. This revision would better protect employees by recognizing 
the latest techniques in electrical safety and by requiring 
installations to incorporate those techniques whenever necessary.

III. History of the Rule

    On February 16, 1972, OSHA incorporated the 1971 edition of the 
National Fire Protection Association's (NFPA) National Electrical Code 
(NEC), NFPA 70-1971, by reference as its electrical standard for 
general industry (37 FR 3431). The Agency followed the procedures 
outlined in Section 6(a) of the Occupational Safety and Health Act of 
1970 (29 U.S.C. 655), which directed the Secretary to adopt existing 
national consensus standards as OSHA standards within 2 years of the 
effective date of the Occupational Safety and Health Act (OSH Act). In 
incorporating the 1971 NEC by reference, OSHA made the entire 1971 NEC 
applicable to all covered electrical installations made after March 15, 
1972. For covered installations made before that date, OSHA listed 
about 20 provisions from the 1971 NEC that applied. No other provisions 
of the 1971 NEC applied to these older installations. Thus, older 
installations were ``grandfathered'' so that they did not need to meet 
most of the requirements in the consensus standard.
    On January 16, 1981, OSHA revised its electrical installation 
standard for general industry (46 FR 4034). This revision replaced the 
incorporation by reference of the 1971 National Electrical Code with 
relevant requirements from Part I of the 1979 edition of NFPA 70E.\5\ 
The revision simplified and clarified the electrical standard and 
updated its provisions to match the 1978 NEC (the latest edition 
available at the time). The standard was written to reduce the need for 
frequent revision and to avoid technological obsolescence. These goals 
were achieved--NFPA 70E had only minor changes over its initial 15 
years of existence. The first substantial changes were introduced in 
the 1995 edition of NFPA 70E.
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    \5\ OSHA added electrical safety-related work practice 
requirements to Subpart S on August 6, 1990 (55 FR 31984). Those 
requirements were based on Part II of 1988 edition of NFPA 70E. 
However, the current rulemaking makes no changes to the safety-
related work practice provisions in Subpart S.
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    The latest edition of NFPA 70E, the 2000 edition, contains a number 
of significant revisions, including a new, alternative method for 
classifying and installing equipment in Class I hazardous locations 
(see preamble Section V. F. ``Zone Classification,'' below). NFPA has 
recommended that OSHA revise its general industry electrical standards 
to reflect the latest edition of NFPA 70E, arguing that such a revision 
would provide a needed update to the OSHA standards and would better 
protect employees. The present proposal responds to NFPA's 
recommendations with regard to installation safety. It also reflects 
the Agency's commitment to update its electrical standards, keep them 
consistent with NFPA standards, and ensure that they appropriately 
protect employees. The Agency intends to extend this commitment by 
using NFPA 70E as the basis for future revisions to its electrical 
safety-related work practice requirements and new requirements for 
electrical maintenance and special equipment.

IV. Legal Authority

    The purpose of the Occupational Safety and Health Act of 1970 (OSH 
Act), 29 U.S.C. 651 et seq., is ``to assure so far as possible every 
working man and woman in the nation safe and healthful working 
conditions and to preserve our human resources.'' 29 U.S.C. 651(b). To 
achieve this goal, Congress authorized the Secretary of Labor to 
promulgate and enforce occupational safety and health standards. 29 
U.S.C. 655(b) and 654(b).
    A safety or health standard ``requires conditions, or the adoption 
or use of one or more practices, means, methods, operations, or 
processes, reasonably necessary or appropriate to provide safe or 
healthful employment or places of employment.'' 29 U.S.C. 652(8). A 
standard is reasonably necessary or appropriate within the meaning of 
Section 652(8) if:
     A significant risk of material harm exists in 
the workplace and the proposed standard would substantially reduce or 
eliminate that workplace risk;
     It is technologically and economically feasible;
     It is cost effective;
     It is consistent with prior Agency action or 
supported by a reasoned justification for departing from prior Agency 
action;
     It is supported by substantial evidence; and
     In the event the standard is preceded by a 
consensus standard, it is better able to effectuate the purposes of the 
OSH Act than the standard it supersedes.
    International Union, UAW v. OSHA (LOTO II), 37 F.3d 655 (D.C. Cir. 
1994).
    OSHA has generally considered an excess risk of 1 death per 1000 
employees over a 45-year working lifetime as clearly representing a 
significant risk. Industrial Union Dept. v. American Petroleum 
Institute (Benzene), 448 U.S. 607, 646 (1980); International Union v. 
Pendergrass (Formaldehyde), 878 F.2d 389, 393 (D.C. Cir. 1989); 
Building and Construction Trades Dept., AFL-CIO v. Brock (Asbestos), 
838 F.2d 1258, 1264-65 (D.C. Cir. 1988).
    A standard is considered technologically feasible if the protective 
measures it requires already exist, can be brought into existence with 
available technology, or can be created with technology that can 
reasonably be expected to be developed. American Textile Mfrs. 
Institute v. OSHA (Cotton Dust), 452 U.S. 490, 513 (1981), American 
Iron and Steel Institute v. OSHA (Lead II), 939 F.2d 975, 980 (D.C. 
Cir. 1991).

[[Page 17777]]

    OSHA generally considers a standard to be cost effective if the 
protective measures it requires are the least costly of the available 
alternatives that achieve the same level of protection. Cotton Dust, 
453 U.S. at 514, n.32; International Union, UAW v. OSHA (LOTO III), 37 
F.3d 655, 668 (D.C. Cir. 1994).
    All OSHA standards must be highly protective, and, where practical, 
``expressed in terms of objective criteria and of the performance 
desired.'' LOTO III, 37 F.3d at 669. Finally, the OSH Act requires that 
when promulgating a rule that differs substantially from a national 
consensus standard, OSHA must explain why the promulgated rule is a 
better method for effectuating the purpose of the Act. 29 U.S.C. 
655(b)(8). As discussed earlier, OSHA is using NFPA 70E as the basis 
for its proposed rule, with some modifications as necessary for 
regulatory and enforcement purposes.
    Electricity has long been recognized as a serious workplace hazard 
exposing employees to dangers such as electric shock, electrocution, 
fires, and explosions. The 100-year-long history of the National 
Electrical Code, originally formulated and periodically updated by 
industry consensus, attests to this fact. The NEC has represented the 
continuing efforts of experts in electrical safety to address these 
hazards and provide standards for limiting exposure in all electrical 
installations, including workplaces. OSHA has determined that 
electrical hazards in the workplace pose a significant risk of injury 
or death to employees, and that this proposed standard, which draws 
heavily on the experience of the NEC, is reasonably necessary to 
provide protection from these hazards.
    According to the U.S. Bureau of Labor Statistics, between 1992 and 
2002, an average of 295 workers died per year from contact with 
electric current, and, between 1992 and 2001, an average of 4,309 
workers lost time away from work because of electrical injuries.\6\ 
Overall, there has been a downward trend in injuries and illnesses, but 
the percentage of decline has varied from year to year. From 1992 to 
2001, the number of injuries involving days away from work decreased by 
29 percent. From 1992 to 2002, the number of deaths decreased by 9 
percent. This downward trend is due, in major part, to 30 years of 
highly protective OSHA regulation in the area of electrical 
installation, based on the NEC and NFPA 70E standards. The proposal 
would carry forward most of the existing requirements for electrical 
installations, with the new and revised requirements intended as fine 
tuning, introducing new technology along with other improvements in 
safety. If employers comply with the proposal, they will prevent unsafe 
electrical conditions from occurring. Thus, OSHA expects this downward 
trend in injuries to continue.
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    \6\ The Survey of Occupational Injuries and Illnesses and the 
Census of fatal occupational injuries, http://www.bls.gov/iif/home.htm#tables.
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    While the number of deaths and injuries associated with electrical 
hazards has declined, contact with electric current still poses a 
significant risk to employees in the workplace. This proposed rule will 
help further reduce the number of deaths and injuries associated with 
electrical hazards by providing additional requirements for 
installation safety and by recognizing alternative means of compliance.

V. Summary and Explanation of the Proposed Rule

A. Scope

    Existing Sec. Sec.  1910.302 through 1910.308 of Subpart S apply to 
electrical installations and utilization equipment used and installed 
in workplaces in general industry and in shipyard employment, 
longshoring, and marine terminals. These sections do not apply to the 
following types of installations:
    (1) Installations in ships, watercraft, railway rolling stock, 
aircraft, or automotive vehicles other than mobile homes and 
recreational vehicles;
    (2) Installations underground in mines; \7\
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    \7\ This exception was incorporated into the current OSHA 
standard solely to be consistent with language used in the NEC and 
NFPA 70E. However, it should be noted that OSHA does not have 
jurisdiction over mines in general, regardless of whether the mining 
activity takes place above ground or underground. Under the Mine 
Safety and Health Act (MSH Act) (30 U.S.C. 801 et seq.), the Mine 
Safety and Health Administration (MSHA) regulates safety and health 
in mines. The MSH Act defines ``mine'' very broadly as:
    (h)(1) ``coal or other mine'' means (A) an area of land from 
which minerals are extracted in nonliquid form or, if in liquid 
form, are extracted with workers underground, (B) private ways and 
roads appurtenant to such area, and (C) lands, excavations, 
underground passageways, shafts, slopes, tunnels and workings, 
structures, facilities, equipment, machines, tools, or other 
property including impoundments, retention dams, and tailings ponds, 
on the surface or underground, used in, or to be used in, or 
resulting from, the work of extracting such minerals from their 
natural deposits in nonliquid form, or if in liquid form, with 
workers underground, or used in, or to be used in, the milling of 
such minerals, or the work of preparing coal or other minerals, and 
includes custom coal preparation facilities. In making a 
determination of what constitutes mineral milling for purposes of 
this chapter, the Secretary shall give due consideration to the 
convenience of administration resulting from the delegation to one 
Assistant Secretary of all authority with respect to the health and 
safety of miners employed at one physical establishment;
    (2) For purposes of subchapters II, III, and IV of this chapter, 
``coal mine'' means an area of land and all structures, facilities, 
machinery, tools, equipment, shafts, slopes, tunnels, excavations, 
and other property, real or personal, placed upon, under, or above 
the surface of such land by any person, used in, or to be used in, 
or resulting from, the work of extracting in such area bituminous 
coal, lignite, or anthracite from its natural deposits in the earth 
by any means or method, and the work of preparing the coal so 
extracted, and includes custom coal preparation facilities;
    For further information, see the Interagency Agreement between 
MSHA and OSHA (http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=MOU&p_ id=222).
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    (3) Installations of railways for generation, transformation, 
transmission, or distribution of power used exclusively for operation 
of rolling stock or installations used exclusively for signaling and 
communication purposes;
    (4) Installations of communication equipment under the exclusive 
control of communication utilities, located outdoors or in building 
spaces used exclusively for such installations; and
    (5) Installations under the exclusive control of electric utilities 
for the purpose of communication or metering; or for the generation, 
control, transformation, transmission, and distribution of electric 
energy. These exempted installations must be located in buildings used 
exclusively by utilities for such purposes or located outdoors on 
property owned or leased by the utility or on public highways, streets, 
roads, etc., or outdoors by established rights on private property.
    These exempted installations present special design considerations 
that are not adequately addressed in Subpart S. For example, electric 
power transmission and distribution installations are typically 
installed where unqualified persons will not have access to them, and 
the only employees working on them are highly trained and skilled. 
Additionally, public safety considerations demand that these 
installations be capable of quick repair when weather or equipment 
failure disrupt electrical service. The National Electrical Safety Code 
(ANSI/IEEE C2), which is developed by experts in electric power 
generation, transmission, and distribution, contains design and 
installation requirements applicable to electric power transmission and 
distribution systems. Section 1910.269 contains OSHA's standard for the 
maintenance of electric power generation, transmission, and 
distribution installations. While it consists mostly of work-practice

[[Page 17778]]

requirements, it does contain several installation requirements. For 
example, Sec.  1910.269(u)(4) and (v)(4) cover guarding of rooms 
containing electric supply equipment in electric power generating 
stations and substations, respectively. OSHA believes that any 
installation requirements for electric power generation, transmission, 
and distribution systems belong in Sec.  1910.269 rather than in 
Subpart S.
    Installations in ships, watercraft, railway rolling stock, 
aircraft, or automotive vehicles (other than mobile homes and 
recreational vehicles) are designed to be transportable.\8\ These 
transportability considerations make many of the design requirements in 
Subpart S irrelevant, at best, or infeasible, at worst. For example, 
attaching the grounded circuit conductor and the equipment grounding 
conductor to a permanent grounding electrode on a transportable wiring 
system is generally not feasible. Thus, the provisions of proposed 
Sec.  1910.304(g)(1), which contains requirements for grounding 
electrical systems, are inappropriate for the wiring of ships, 
watercraft, railway rolling stock, aircraft, or automotive vehicles. By 
contrast, however, wiring that is not a part of the wiring of the ship, 
watercraft, railway rolling stock, aircraft, or automotive vehicle 
would be covered by Subpart S, as appropriate. For example, a portable 
electric drill carried into the cargo area of a truck would be covered 
by Subpart S if it is plugged into the wiring of a service station.
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    \8\ Although the wiring of recreational vehicles and mobile 
homes is transportable, it is also designed to be attached to 
specially designed, permanently installed power distribution 
outlets. This type of hybrid system must be designed for both 
permanent and transportable uses.
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    In regard to ships, there has been some confusion about whether the 
``exemption'' applies to all wiring or electrical installations brought 
on board a vessel during construction, overhaul, or repair, even when 
the wiring is supplied by shore-based electric power--or whether it 
only applies to the ships' own wiring. OSHA is hereby clarifying its 
position.
    The ``exempted'' types of installations in both the current and 
proposed standards are identical to those ``exempted'' by the National 
Electrical Code and NFPA 70E, which form the basis of both. 
Installations covered under the existing standard would continue to be 
covered under the proposal. For example, in longshoring operations and 
related employments, this proposal would apply to electrical 
installations aboard vessels only if they are shore-based as stated in 
Sec.  1918.1(b)(3). Electrical installations in marine terminals are 
covered under Subpart S, as noted in Sec.  1917.1(a)(2)(iv). (The 
marine terminals standard in Part 1917 applies to the loading, 
unloading, movement or other handling of cargo, ship's stores or gear 
within the terminal or into or out of any land carrier, holding or 
consolidation area, and any other activity within and associated with 
the overall operation and function of the terminal. This includes the 
use and routine maintenance of facilities and equipment and cargo 
transfer accomplished with the use of shore-based material handling 
devices. See Sec.  1917.1(a).)
    Section 1910.5 governs how the general industry electrical 
standards apply to shipyard employment. According to Sec.  
1910.5(c)(2), the general standards in Part 1910 apply to the extent 
that no industry-specific standard (such as Subpart K of Part 1926 for 
construction) applies to the ``same condition, practice, means, method, 
operation, or process.'' Part 1915 contains few requirements related to 
electrical safety. Paragraph (b) of Sec.  1915.93 contains four such 
requirements, for grounding of vessels, the safety of the vessel's 
wiring, overcurrent protection, and guarding of infrared heat lamps. 
Section 1915.92 contains provisions on electric lighting, and Sec.  
1915.132 contains requirements on portable electric tools. Section 
1915.181 contains electrical safety-related work practices for 
deenergizing electric circuits and protecting employees against contact 
with live parts during electrical work. In addition, Part 1915 contains 
several other miscellaneous electrical safety-related work practices 
and electrical design requirements. These provisions continue to apply 
in lieu of any corresponding requirements in Subpart S of Part 1910. 
Conversely, where there is no specific standard for shipyard employment 
in Part 1915, Subpart S of Part 1910 applies.\9\
---------------------------------------------------------------------------

    \9\ It should be noted that, unlike the shipyard employment 
standards, OSHA's construction standards have a comprehensive 
electrical installation standard in Subpart K of Part 1926, which 
covers all aspects of electrical safety that are addressed in the 
electrical installation standard for general industry. Thus, none of 
the electrical installation requirements in Subpart S of Part 1910 
apply in construction.
---------------------------------------------------------------------------

    As noted earlier, Subpart S does not cover installations in ships, 
but it does cover installations used on ships if the installation is 
shore-based (that is, not part of the vessel's internal electrical 
system). Thus, Sec.  1910.303(g)(2) (guarding live parts) applies to 
the wiring of the shipyard and to any wiring taken onto the ship when 
it is supplied by the shipyard wiring. It does not apply to the ship's 
wiring. The proposed rule does not change this scope of coverage. 
However, OSHA invites comments on whether it needs to clarify this 
coverage further.

B. Grandfather Clause

    The proposal, as does the current rule, exempts older electrical 
installations from meeting some of the provisions of the Design Safety 
Standards for Electrical Systems (that is, Sec. Sec.  1910.302 through 
1910.308). The extent to which OSHA's electrical installation standard 
applies depends on the date the installation was made. Older 
installations must meet fewer requirements than newer ones. The 
proposal's grandfathering of older installations, contained in 
paragraph (b) of proposed Sec.  1910.302, is patterned after the 
current standard's grandfather provisions in existing Sec.  
1910.302(b). Most of the new provisions contained in the proposed rule 
would only apply prospectively, to installations made after the 
effective date of the final rule.
    The following paragraphs explain proposed Sec.  1910.302(b) in the 
following order: paragraph (b)(1), requirements applicable to all 
installations; paragraph (b)(4), requirements applicable only to 
installations made after the effective date of the revised standard; 
paragraph (b)(3), requirements applicable only to installations made 
after April 16, 1981; and paragraph (b)(2), requirements applicable 
only to installations made after March 15, 1972.
    Requirements applicable to all installations. Paragraph (b)(1) of 
proposed Sec.  1910.302 contains a list of provisions that would apply 
to all installations, regardless of when they were designed or 
installed. The few requirements in this short list are so essential to 
employee safety that even the oldest electrical installations must be 
modified, if necessary, to meet them. The list is unchanged from the 
current standard, except for the addition of the zone classification 
system and a documentation requirement from proposed Sec.  1910.307. As 
discussed in more detail later in this section of the preamble, the 
only substantial new provisions being proposed in Sec.  1910.307 are: 
(1) New requirements in Sec.  1910.307(g) pertaining to electric 
equipment installed in Class I hazardous locations if the employer 
chooses to use the zone classification system and (2) a new requirement 
in Sec.  1910.307(b) for employers to document the extent of each 
hazardous location. This second provision applies

[[Page 17779]]

to older installations only if the employer is using the zone 
classification system.
    The new requirements pertaining to zone classification in proposed 
Sec.  1910.307(g) provide employers with an alternative installation 
method that the current standard does not permit.\10\ Thus, applying 
these provisions to older installations would give employers greater 
flexibility without imposing any new costs.
---------------------------------------------------------------------------

    \10\ See the discussion under the heading ``Zone 
Classification'' for an explanation of the zone classification 
system and its differences from the current standard's division 
classification system.
---------------------------------------------------------------------------

    Paragraph (b) of Sec.  1910.307 proposes a new requirement that 
employers document areas designated as hazardous (classified) 
locations. This requirement would ensure that the employer has records 
of the extent and classification of each such area. The documentation 
would help employers determine what type of equipment was needed in 
these locations and would inform employees of the need for special care 
in the maintenance of the electric equipment installed there. OSHA has 
carefully considered the need to document these areas and has tried to 
balance that need with the extensive burden that would be placed on 
employers who would have to survey and document their existing 
hazardous locations.
    The current standard's division classification system has been in 
place for many years, and most employers and inspection authorities are 
familiar with the boundaries for Class I, Division 1 and Class I, 
Division 2 locations. An employee servicing equipment in a Class I, 
Division 1 or 2 location can obtain this information relatively easily 
even if the employer has not documented the boundaries. Accordingly, 
OSHA believes that the benefit of documenting existing hazardous 
locations installed using the division classification system would be 
minimal. Therefore, for employers using the division system, OSHA is 
proposing to require documentation of boundaries only for new 
installations made after the effective date of the standard. Employers 
would not need to document existing division-classified systems.
    On the other hand, the zone classification system is relatively 
new. Most employers are not familiar with this system and have little 
experience determining how to draw the boundaries between the three 
zones. Relatively few NFPA or industry standards provide specifications 
for placing those boundaries. Furthermore, the existing OSHA electrical 
standard recognizes only installations made in accordance with the 
division classification system, not the zone classification system. Any 
existing installation made under the zone system is technically out of 
compliance with OSHA's existing standard. However, because the NEC 
represents standard industry practice, existing zone system 
installations will almost certainly have been installed in accordance 
with an edition of the NEC that recognizes the zone classification 
system (the 1999 and 2002 editions). These editions of the NEC 
explicitly require documentation of hazardous locations. Thus, an 
employer with an existing installation made under the zone 
classification system should already have the documentation required by 
Sec.  1910.307(b). Therefore, OSHA believes that the benefits of having 
documentation for existing zone-classified installations justify the 
small burden that would be placed on employers. For these reasons, OSHA 
is proposing to apply the documentation requirement to all hazardous 
location installations made under the zone classification system. This 
will provide employers, employees, and OSHA with information critical 
for determining which equipment is suitable in a given hazardous 
location.
    Requirements applicable only to installations made after the 
effective date of the final rule. Paragraph (b)(4) of proposed Sec.  
1910.302 would make the following provisions applicable only to 
installations made or overhauled \11\ after the effective date of the 
final rule:
---------------------------------------------------------------------------

    \11\ See the discussion of the term ``overhaul'' later in this 
section of the preamble.

Sec.  1910.303(f)(4)--Disconnecting means and circuits--Capable of 
accepting a lock
Sec.  1910.303(f)(5)--Disconnecting means and circuits--Marking for 
series combination ratings
Sec.  1910.303(g)(1)(iv) and (g)(1)(vii)--600 Volts, nominal, or less--
Space about electric equipment
Sec.  1910.303(h)(5)(vi)--Over 600 volts, nominal--Working space and 
guarding
Sec.  1910.304(b)(1)--Branch circuits--Identification of multiwire 
branch circuits
Sec.  1910.304(b)(3)--Branch circuits--Identification of ungrounded 
conductors
Sec.  1910.304(b)(4)(i)--Branch circuits--Ground-fault circuit 
interrupter protection for personnel
Sec.  1910.304(f)(2)(i)(A), (f)(2)(i)(B) (but not the introductory text 
to Sec.  1910.304(f)(2)(i), and (f)(2)(iv)(A)--Overcurrent protection--
Overcurrent protection, feeders and branch circuits for over 600 volts, 
nominal
Sec.  1910.305(a)(3)(v)--Wiring methods--Cable trays
Sec.  1910.305(c)(3)(ii)--Switches--Connection of switches
Sec.  1910.305(c)(5)--Switches--Grounding
Sec.  1910.306(a)(1)(ii)--Electric signs and outline lighting--
Disconnecting means
Sec.  1910.306(c)(4)--Elevators, dumbwaiters, escalators, moving walks, 
wheelchair lifts, and stairway chair lifts--Operation
Sec.  1910.306(c)(5)--Elevators, dumbwaiters, escalators, moving walks, 
wheelchair lifts, and stairway chair lifts--Location
Sec.  1910.306(c)(6)--Elevators, dumbwaiters, escalators, moving walks, 
wheelchair lifts, and stairway chair lifts--Identification and signs
Sec.  1910.306(c)(7)--Elevators, dumbwaiters, escalators, moving walks, 
wheelchair lifts, and stairway chair lifts--Single-car and multicar 
installations
Sec.  1910.306(j)(1)(iii)--Swimming pools, fountains, and similar 
installations--Receptacles
Sec.  1910.306(k)--Carnivals, circuses, fairs, and similar events
Sec.  1910.308(a)(5)(v) and (a)(5)(vi)(B)--Systems over 600 volts, 
nominal--Interrupting and isolating devices
Sec.  1910.308(a)(7)(vi)--Systems over 600 volts, nominal--Tunnel 
installations
Sec.  1910.308(b)(3)--Emergency power systems--Signs
Sec.  1910.308(c)(3)--Class 1, Class 2, and Class 3 remote control, 
signaling, and power-limited circuits--Separation from conductors of 
other circuits
Sec.  1910.308(f)--Solar photovoltaic systems

    These provisions are based on requirements that have been added to 
the National Electrical Code since the 1978 edition. OSHA has never 
required employers to comply with these requirements, and the Agency 
believes that the modest increase in employee protection that would 
result from compliance with them would not be worth the substantial 
expense that employers would incur if existing installations had to be 
retrofitted to conform to those provisions. On the other hand, 
employers would incur minimal costs to achieve this increase in 
protection if they only needed to assure that new installations comply 
with the listed provisions. In local jurisdictions requiring compliance 
with the NEC, there should be no additional costs involved, because the 
installations would already conform to the new OSHA requirements. The 
Agency believes that even in other jurisdictions, the vast majority of 
installations already

[[Page 17780]]

comply with the latest edition of the NEC, because compliance with the 
latest Code is standard industry practice.
    OSHA is considering making the new requirements in revised Subpart 
S effective 90 days after the final rule is published in the Federal 
Register. The Agency requests comments on whether this provides 
sufficient time to implement the changes required by the revised 
standard. It should be noted that applying new provisions only to new 
installations is the same approach that OSHA took in promulgating the 
current version of Subpart S in 1981. The Agency found that this 
approach was successful and has no indication that it was unduly 
burdensome or insufficiently protective.
    There are also many provisions in proposed Subpart S that are not 
contained in the existing standard but cannot be considered totally 
``new'' provisions. Most of these ``new'' requirements were actually 
contained in the 1971 NEC. Table 1 lists these ``new'' provisions and 
denotes their counterparts in the 1971 NEC. From March 15, 1972, until 
April 16, 1981, Subpart S incorporated the 1971 NEC by reference in its 
entirety. Accordingly, OSHA required employers to comply with every 
requirement in the 1971 NEC for any new installation made between those 
dates and for any replacement, modification, repair, or rehabilitation 
made during that period. The current standard, which became effective 
on April 16, 1981, omitted many of the detailed provisions of the NEC 
because they were already addressed by the more general requirements 
that were contained in the OSHA standard. For example, OSHA did not 
carry forward 1971 NEC Section 110-11, which required equipment to be 
suitable for the environment if it is installed where the environment 
could cause deterioration. However, the requirement for equipment to be 
suitable for the location in which it was installed is implicit in the 
more general requirements in existing Sec.  1910.303(a) that equipment 
be approved and in existing Sec.  1910.303(b)(2) that equipment be 
installed in accordance with any instructions included in its listing 
or labeling. (Equipment that is not suitable for installation in 
deteriorating environments, such as wet or damp locations, will include 
instructions warning against such installation. These instructions are 
required by the nationally recognized laboratory listing or labeling 
the product.)
    Even though OSHA has not required employers to maintain their 
installations in compliance with these older provisions, the Agency 
believes that employers' installations actually do comply with those 
requirements. The vast majority of employers are following the entire 
National Electrical Code applicable to their installations, as noted in 
the Economic Analysis section of this preamble.\12\ For these reasons, 
OSHA is not proposing to exempt installations made after March 15, 
1972, from meeting any provision listed in Table 1 and is not including 
any of these provisions in Sec.  1910.302(b)(4) (the list of provisions 
that apply only to new installations). The Agency invites public 
comment on whether this approach is reasonable.
---------------------------------------------------------------------------

    \12\ All of the requirements in question appear in some version 
in every edition of the NEC since 1972.

                             Table 1.--``New'' Provisions Contained in 1971 NEC\13\
----------------------------------------------------------------------------------------------------------------
            Proposed provision                     Equivalent 1971 NEC section                  Subject
----------------------------------------------------------------------------------------------------------------
Sec.   1910.303(b)(3).....................  110-20                                     Insulation integrity.
    (b)(4)................................  110-9                                      Interrupting rating.
    (b)(5)................................  110-10                                     Circuit impedance and
                                                                                        other characteristics.
    (b)(6)................................  110-11                                     Deteriorating agents.
    (b)(7)................................  110-12                                     Mechanical execution of
                                                                                        work.
    (b)(8)................................  110-4(a) and (d)                           Mounting and cooling of
                                                                                        equipment.
                                            110-12
                                            110-13
    (c)(1)................................  110-14                                     Electrical connections,
                                                                                        general.
Sec.   1910.304(b)(2).....................  210-21(b)                                  Branch circuits,
                                                                                        receptacles and cord
                                                                                        connectors.
    (b)(5)................................  210-21                                     Branch circuits, outlet
                                                                                        devices.
    (b)(6)................................  210-22                                     Branch circuits, cord
                                                                                        connections.
    (e)(1)(iv)............................  230-70(c)                                  Services, disconnecting
                                                                                        means.
    (f)(1)(ix)............................  110-9                                      Overcurrent protection,
                                                                                        600 volts, nominal, or
                                                                                        less, circuit breaker
                                                                                        ratings.
                                            240-11
    (f)(2), except for (f)(2)(i)(A),         240-5                                     Overcurrent protection,
     (f)(2)(i)(B), and (f)(2)(iv)(A).                                                   feeders and branch
                                                                                        circuits over 600 volts,
                                                                                        nominal.
                                            240-11
                                            240-15
Sec.   190.305(a)(4)(ii)..................  320-5                                      Open wiring on
                                                                                        insulators, support.
    (b)(1)(iii)...........................  370-7                                      Conductors entering
                                                                                        cabinets, boxes, and
                                                                                        fittings, securing
                                                                                        conductors.
                                            373-5
    (b)(2)(ii)............................  370-15(b)                                  Fixture canopy or pan
                                                                                        installed in a
                                                                                        combustible wall or
                                                                                        ceiling.
    (e)(1)................................  373-2                                      Airspace for enclosures
                                                                                        installed in wet or damp
                                                                                        locations.
                                            384-5
    (h)(3)................................  710-6                                      Portable cables,
                                                                                        grounding conductors.
    (j)(2)(i).............................  410-52(d)                                  Receptacles, cord
                                                                                        connectors, and
                                                                                        attachment plugs; no
                                                                                        exposed energized parts.
    (j)(2)(iv) through (j)(2)(vii)........  410-54                                     Receptacles installed in
                                                                                        wet or damp locations.
    (j)(3)(ii)............................  422-20                                     Appliances, disconnecting
                                                                                        means.
    (j)(3)(iii)...........................  422-30(a)                                  Appliances, nameplates.
    (j)(3)(iv)............................  422-30(b)                                  Appliances, marking to be
                                                                                        visible after
                                                                                        installation.
    (j)(6)(ii)(A).........................  110-9                                      Capacitor switches.
                                            110-10

[[Page 17781]]

 
                                            460-8(c)(4)
    (j)(6)(ii)(B).........................  460-8(c)(1)                                Capacitor disconnecting
                                                                                        means.
Sec.   1910.306(c)(3).....................  620-51(a)                                  Elevators, dumbwaiters,
                                                                                        escalators, moving
                                                                                        walks, wheelchair lifts,
                                                                                        and stairway chair
                                                                                        lifts; type of
                                                                                        disconnecting means.
    (c)(10)...............................  620-72                                     Elevators, dumbwaiters,
                                                                                        escalators, moving
                                                                                        walks, wheelchair lifts,
                                                                                        and stairway chair
                                                                                        lifts; motor
                                                                                        controllers.
    (d)(1)................................  630-13                                     Arc welders,
                                                                                        disconnecting means.
                                            630-23
    (g)(1)(iii)...........................  665-34                                     Induction and dielectric
                                                                                        heating equipment,
                                                                                        detachable panels used
                                                                                        for access to live
                                                                                        parts.
    (g)(1)(vi)............................  665-8                                      Induction and dielectric
                                                                                        heating equipment,
                                                                                        ampere rating of
                                                                                        disconnecting means.
    (j)(4)(iii)...........................  680-20(a)(4)                               Swimming pools,
                                                                                        fountains, and similar
                                                                                        installations,
                                                                                        underwater fixtures
                                                                                        facing upwards.
Sec.   1910.308(a)(2).....................  710-4                                      Systems over 600 volts,
                                                                                        nominal; open
                                                                                        installations of braid-
                                                                                        covered insulated
                                                                                        conductors.
    (a)(3)(i).............................  710-6                                      Systems over 600 volts,
                                                                                        nominal; insulation
                                                                                        shielding terminations.
    (a)(4)................................  710-8                                      Systems over 600 volts,
                                                                                        nominal; moisture or
                                                                                        mechanical protection
                                                                                        for metal-sheathed
                                                                                        cables.
    (a)(5)(i).............................  710-21(a)                                  Systems over 600 volts,
                                                                                        nominal; interrupting
                                                                                        and isolating devices;
                                                                                        guarding and indicating.
    (a)(5)(ii)............................  240-11(a)                                  Systems over 600 volts,
                                                                                        nominal; interrupting
                                                                                        and isolating devices;
                                                                                        fuses.
                                            710-21(b)
    (a)(5)(iii) and (a)(5)(iv)............  710-21(b)                                  Systems over 600 volts,
                                                                                        nominal; interrupting
                                                                                        and isolating devices;
                                                                                        fused cutouts.
    (a)(5)(vi), but not (a)(5)(vi)(B).....  710-21(c)                                  Systems over 600 volts,
                                                                                        nominal; interrupting
                                                                                        and isolating devices;
                                                                                        load interrupter
                                                                                        switches.
    (a)(5)(vii)...........................  710-22                                     Systems over 600 volts,
                                                                                        nominal; interrupting
                                                                                        and isolating devices;
                                                                                        means for isolating
                                                                                        equipment.
    (b)(2)................................  700-14                                     Emergency systems,
                                                                                        emergency illumination.
----------------------------------------------------------------------------------------------------------------
\13\ These provisions have no counterpart in existing Subpart S, but were in the 1971 National Electrical Code.

    In addition, OSHA is not including in the list of new provisions in 
proposed Sec.  1910.302(b)(4) any proposed provision that merely 
provides an alternative means of compliance for an existing 
requirement. For example, as noted earlier, Sec.  1910.307(g) provides 
alternative requirements for installations in hazardous (classified) 
locations based on the zone classification system rather than the 
division classification system that is required under the existing 
standard. Such requirements accept alternative installation techniques 
recognized as being equally protective by the NEC and NFPA 70E, and 
there is no need to limit them to new installations.
    OSHA also believes that there is no need to grandfather 
requirements that apply only to temporarily installed equipment and 
wiring.\14\ The few new requirements applying to temporarily installed 
equipment and wiring have been in the National Electrical Code since at 
least 1999 and, in most cases, since before that. Employers should 
already be in compliance with such requirements since the temporary 
installations almost certainly were put into place well after 1999. For 
example, proposed Sec.  1910.304(b)(4)(ii) contains requirements for 
providing ground-fault circuit interrupter protection for temporary 
wiring installations that are used during maintenance, remodeling, or 
repair of buildings, structures, or equipment or during similar 
activities. Temporary wiring installations used for any of these 
purposes were likely to have been installed well after 1999. An 
employer who is complying with the 1999 or later edition of the NEC 
will already be complying with this provision of the proposal. Even 
employers who are not complying with recent versions of the NEC for 
temporary wiring will face only the minimal cost of providing ground-
fault circuit interrupters; no changes would need to be made to any 
existing permanent wiring, which might involve considerably more costs. 
The Agency requests comments on whether any new requirements applying 
only to temporarily installed equipment or wiring should also be listed 
in Sec.  1910.302(b)(4), and why.
---------------------------------------------------------------------------

    \14\ For the purposes of this discussion, ``temporarily 
installed equipment or wiring'' is wiring and equipment installed on 
a short-term rather than a long-term or permanent basis. It includes 
temporary wiring covered by proposed Sec.  1910.305(a)(2) and other 
equipment and wiring similarly installed on a short-term basis.
---------------------------------------------------------------------------

    Additionally, OSHA recognizes that, in a proposed standard this 
extensive, some new requirements might have been overlooked and some 
subtle changes in existing requirements might have unanticipated 
consequences. Therefore, the Agency requests comments on whether there 
are any other new or revised requirements in the proposal that should 
not apply to existing installations.
    Requirements applicable only to installations made after April 16, 
1981. Paragraph (b)(3) of Sec.  1910.302 lists requirements that apply 
only to installations made after April 16, 1981. This proposed 
paragraph carries forward essentially the same list as is currently in 
Sec.  1910.302(b)(3). No provisions have been added to or removed from 
the list.
    Requirements applicable only to installations made after March 15, 
1972. Paragraph (b)(2) of existing Sec.  1910.302 requires all 
installations made after March 15, 1972, and every major replacement, 
modification, repair, or rehabilitation made after that date to meet 
all the installation requirements in Subpart S except for those listed 
in Sec.  1910.302(b)(3) and (b)(4). A note following existing Sec.  
1910.302(b)(2) indicates that ``major replacements, modifications, 
repairs, or rehabilitations'' include work similar to that involved 
when a new building or

[[Page 17782]]

facility is built, a new wing is added, or an entire floor is 
renovated.
    Paragraph (b)(2) of proposed Sec.  1910.302 would require all 
installations built or overhauled after March 15, 1972, to comply with 
all of the requirements of Sec. Sec.  1910.302 through 1910.308, except 
as provided in Sec.  1910.302(b)(3) and (b)(4). As discussed earlier, 
these latter two paragraphs limit the application of newer provisions 
of Subpart S to installations made during later periods.
    In the proposal, OSHA is introducing the term ``overhaul'' to 
include the types of activities that would trigger compliance with the 
otherwise grandfathered provisions of Subpart S for older 
installations. ``Overhaul'' is defined as follows:

    Overhaul means to perform a major replacement, modification, 
repair, or rehabilitation similar to that involved when a new 
building or facility is built, a new wing is added, or an entire 
floor is renovated.

    Thus, this new term, which is based on language in current Subpart 
S, incorporates all the elements of ``major replacement, modification, 
or rehabilitation'' in the text of existing Sec.  1910.302(b)(2) and in 
the note following that provision. OSHA believes that the proposed 
language will simplify the standard without making any substantive 
change to the way in which Subpart S applies to older installations.

C. Summary of Changes in Sec. Sec.  1910.303 Through 1910.308

    The Distribution Table for Subpart S lists all the provisions and 
sections from Sec. Sec.  1910.303 through 1910.308 of the electrical 
standard. This table summarizes any proposed changes being made to the 
standard that involve grammatical edits, additions, removals, and 
paragraph numbers. There are places in the standard where no 
substantial change is made. Most of the changes are editorial in 
nature. Some of the requirements would be removed because the material 
is considered outdated. However, the substantive changes to be made to 
the standard will be discussed in further detail following this 
section.

                           Distribution Table
------------------------------------------------------------------------
                                                       Description of
        OLD--section              NEW--section           changes and
                                                          rationale
------------------------------------------------------------------------
                  See the note at the end of the table
------------------------------------------------------------------------
Sec.   1910.303 General.....  Sec.   1910.303       ....................
                               General.
1910.303(a).................  1910.303(a).........  No substantive
                                                     change. A reference
                                                     to the Sec.
                                                     1910.399 definition
                                                     of ``approved'' is
                                                     added for
                                                     clarification.
1910.303(b)(1), introductory  1910.303(b)(1),       No substantive
 text.                         introductory text.    change.
1910.303(b)(1)(i)...........  1910.303(b)(1)(i)...  No substantive
                                                     change.
1910.303(b)(1)(ii)..........  1910.303(b)(1)(ii)..  No substantive
                                                     change.
                              1910.303(b)(1)(iii).  **Adds wire-bending
                                                     and connection
                                                     space to the list
                                                     of things to
                                                     consider when
                                                     judging equipment.
1910.303(b)(1)(iii).........  1910.303(b)(1)(iv)..  No substantive
                                                     change.
1910.303(b)(1)(iv)..........  1910.303(b)(1)(v)...  No substantive
                                                     change.
1910.303(b)(1)(v)...........  1910.303(b)(1)(vi)..  No substantive
                                                     change.
1910.303(b)(1)(vi)..........  1910.303(b)(1)(vii).  No substantive
                                                     change.
1910.303(b)(1)(vii).........  1910.303(b)(1)(viii)  No substantive
                                                     change.
1910.303(b)(2)..............  1910.303(b)(2)......  No substantive
                                                     change.
                              1910.303(b)(3)......  **Adds a requirement
                                                     for completed
                                                     wiring to be free
                                                     from short circuits
                                                     and grounds other
                                                     than those required
                                                     in the standard.
                              1910.303(b)(4)......  **Adds requirements
                                                     for equipment
                                                     intended to
                                                     interrupt current
                                                     to have adequate
                                                     interrupting
                                                     ratings.
                              1910.303(b)(5)......  **Adds requirements
                                                     for the
                                                     coordination of
                                                     overcurrent
                                                     protection for
                                                     circuits and
                                                     equipment.
                              1910.303(b)(6)......  **Adds a requirement
                                                     for conductors and
                                                     equipment to be
                                                     identified for the
                                                     purpose when
                                                     installed in an
                                                     environment
                                                     containing
                                                     deteriorating
                                                     agents.
                              1910.303(b)(7)......  **Adds requirements
                                                     for installing
                                                     electric equipment
                                                     in a neat and
                                                     workmanlike manner.
                              1910.303(b)(8)......  **Adds requirements
                                                     for equipment to be
                                                     mounted securely
                                                     and to allow for
                                                     proper cooling.
                              1910.303(c)(1)......  **Adds requirements
                                                     to ensure that
                                                     electrical
                                                     connections are
                                                     secure and
                                                     electrically safe.
                              1910.303(c)(2)(i)...  **Adds requirements
                                                     for connections at
                                                     terminals.
                              1910.303(c)(2)(ii)..  **Adds requirements
                                                     for the
                                                     identification of
                                                     terminals intended
                                                     for connection to
                                                     more than one
                                                     conductor or to
                                                     aluminum.
1910.303(c).................  1910.303(c)(3)(i)...  No substantive
                                                     change.
                              1910.303(c)(3)(ii)..  **Adds a requirement
                                                     that wire
                                                     connectors or
                                                     splicing means
                                                     installed on
                                                     directly buried
                                                     conductors be
                                                     listed for such
                                                     use.

[[Page 17783]]

 
1910.303(d).................  1910.303(d).........  No substantive
                                                     change.
1910.303(e).................  1910.303(e).........  No substantive
                                                     change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.303(f).................  1910.303(f)(1)......  No substantive
                              1910.303(f)(2)......   change. (Individual
                              1910.303(f)(3)......   requirements are
                                                     placed in separate
                                                     paragraphs.)
                              1910.303(f)(4)......  Adds a requirement
                                                     for disconnecting
                                                     means required by
                                                     Subpart S to be
                                                     capable of
                                                     accepting a lock.
                                                     This provision is
                                                     added to make the
                                                     Subpart S
                                                     requirements on
                                                     disconnecting means
                                                     consistent with
                                                     Sec.
                                                     1910.147(c)(2)(iii)
                                                     , which requires
                                                     energy isolating
                                                     devices (a generic
                                                     term, which
                                                     includes electrical
                                                     disconnecting
                                                     means) to be
                                                     designed to accept
                                                     a lockout device.
                              1910.303(f)(5)......  **Adds marking
                                                     requirements for
                                                     series combination
                                                     ratings of circuit
                                                     breakers or fuses.
1910.303(g)(1), introductory  1910.303(g)(1),       No substantive
 text.                         introductory text.    change.
1910.303(g)(1)(i)...........  1910.303(g)(1)(i)...  **The proposal
                              Table S-1, Note 3...   revises the
                                                     language to clarify
                                                     how wide and high
                                                     the clear space
                                                     must be.
1910.303(g)(1)(ii)..........  1910.303(g)(1)(ii)..  No substantive
                                                     change.
1910.303(g)(1)(iii).........  1910.303(g)(1)(iii).  No substantive
                                                     change.
                              1910.303(g)(1)(iv)..  **Adds a requirement
                                                     for a second
                                                     entrance on
                                                     equipment rated
                                                     1200 amperes under
                                                     certain conditions.
1910.303(g)(1)(iv)..........  1910.303(g)(1)(i)(B)  **Reduced the
                                                     minimum width of
                                                     the clear space to
                                                     762 mm.
1910.303(g)(1)(v)...........  1910.303(g)(1)(v)...  **Adds a prohibition
                                                     against controlling
                                                     illumination for
                                                     working spaces by
                                                     automatic means
                                                     only.
1910.303(g)(1)(vi)..........  1910.303(g)(1)(vi)..  **Increased the
                                                     minimum height of
                                                     the working space
                                                     from 1.91m to 1.98m
                                                     for new
                                                     installations.
                              1910.303(g)(1)(vii).  ** Adds requirements
                                                     for switchboards,
                                                     panelboards, and
                                                     distribution boards
                                                     installed for the
                                                     control of light
                                                     and power circuits,
                                                     and motor control
                                                     centers to be
                                                     installed in
                                                     dedicated space and
                                                     to be protected
                                                     against damage.
1910.303(g)(2)(i)...........  1910.303(g)(2)(i)...  No substantive
                                                     change.
1910.303(g)(2)(ii)..........  1910.303(g)(2)(ii)..  No substantive
                                                     change.
1910.303(g)(2)(iii).........  1910.303(g)(2)(iii).  No substantive
                                                     change.
1910.303(h)(1)..............  1910.303(h)(1)......  No substantive
                                                     change.
1910.303(h)(2), introductory  1910.303(h)(2)(i)...  **The minimum height
 text.                        1910.303(h)(2)(ii)..   of fences
                                                     restricting access
                                                     to electrical
                                                     installations over
                                                     600 V is reduced
                                                     from 2.44 m to 2.13
                                                     m.
1910.303(h)(2)(i)...........  1910.303(h)(2)(iii).  **1. The proposal
1910.303(h)(2)(ii)..........  1910.303(h)(2)(iv)..   organizes these
                              1910.303(h)(2)(v)...   requirements on the
                              1910.303(h)(5)(iii).   basis of whether
                                                     the installations
                                                     are indoors or
                                                     outdoors. (The
                                                     existing standard
                                                     organizes them on
                                                     the basis of
                                                     whether or not the
                                                     installations are
                                                     accessible to
                                                     unqualified
                                                     employees.)
                                                    2. Adds requirements
                                                     intended to prevent
                                                     tampering by the
                                                     general public.
                                                    3. Removes
                                                     requirement to lock
                                                     underground box
                                                     covers weighing
                                                     more than 45.4 kg.
1910.303(h)(3), introductory  1910.303(h)(3)......  No substantive
 text.                                               change.
1910.303(h)(3)(i)...........  1910.303(h)(5)(i)...  **The distances in
                              Table S-2, Note 3...   Table S-2 for the
                                                     depth of working
                                                     space in front of
                                                     electric equipment
                                                     are increased for
                                                     new installations
                                                     to match the
                                                     distances in NFPA
                                                     70E-2000.
1910.303(h)(3)(ii)..........  1910.303(h)(5)(iv)..  No substantive
                                                     change.
1910.303(h)(3)(iii).........  1910.303(h)(5)(v)...  **The distances in
                                                     Table S-3 for the
                                                     elevations of
                                                     unguarded live
                                                     parts are increased
                                                     for new
                                                     installations to
                                                     match the distances
                                                     in NFPA 70E-2000.

[[Page 17784]]

 
1910.303(h)(4)(i)...........  1910.303(h)(4)(i)...  **The existing
                                                     standard requires a
                                                     second entrance to
                                                     give access to the
                                                     working space about
                                                     switchboards and
                                                     control panels over
                                                     600 V if the
                                                     equipment exceed
                                                     1.22 m in width if
                                                     it is practical to
                                                     install a second
                                                     entrance. The
                                                     proposal requires
                                                     an entrance on each
                                                     end of switchboards
                                                     and panelboards
                                                     exceeding 1.83 m
                                                     unless the working
                                                     space permits a
                                                     continuous and
                                                     unobstructed way of
                                                     travel or the
                                                     working space is
                                                     doubled. In
                                                     addition, the
                                                     proposal requires
                                                     the lone entrance
                                                     permitted under
                                                     either of these
                                                     exceptions to be at
                                                     least the distance
                                                     specified in Table
                                                     S-2 from exposed
                                                     live parts.
1910.303(h)(4)(ii)..........  1910.303(h)(4)(ii)..  No substantive
                                                     change.
                              1910.303(h)(5)(ii)..  **Adds requirements
                                                     for equipment
                                                     operating at 600 V
                                                     or less installed
                                                     in rooms or
                                                     enclosures
                                                     containing exposed
                                                     live parts or
                                                     exposed wiring
                                                     operating at more
                                                     than 600 V.
                              1910.303(h)(5)(vi)..  **Adds requirements
                                                     limiting the
                                                     installation of
                                                     pipes or ducts that
                                                     are foreign to
                                                     electrical
                                                     installation
                                                     operating at more
                                                     than 600 V.
Sec.   1910.304 Wiring        Sec.   1910.304       ....................
 design and protection.        Wiring design and
                               protection..
1910.304(a)(1)..............  1910.304(a)(1)......  No substantive
                                                     change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.304(a)(2)..............  1910.304(a)(2)......  No substantive
                                                     change.
1910.304(a)(3)..............  1910.304(a)(3)......  No substantive
                                                     change.
                              1910.304(b)(1)......  **Adds requirements
                                                     for the
                                                     identification of
                                                     multiwire branch
                                                     circuits.
                              1910.304(b)(2)(i)...  **Adds requirements
                                                     that receptacles
                                                     installed on 15-
                                                     and 20-ampere
                                                     circuits be of the
                                                     grounding type and
                                                     that grounding-type
                                                     receptacles be
                                                     installed in
                                                     circuits within
                                                     their rating.
                              1910.304(b)(2)(ii)..  **Adds a requirement
                                                     for grounding
                                                     contacts on
                                                     receptacles to be
                                                     effectively
                                                     grounded.
                              1910.304(b)(2)(iii).  **Adds requirements
                                                     on the methods used
                                                     to ground
                                                     receptacles and
                                                     cord connectors.
                              1910.304(b)(2)(iv)..  **Adds requirements
                                                     on the replacement
                                                     of receptacles.
                              1910.304(b)(2)(v)...  **Adds a requirement
                                                     that receptacles
                                                     installed on branch
                                                     circuits having
                                                     different voltages,
                                                     frequencies, or
                                                     types of current be
                                                     noninterchangeable.
                              1910.304(b)(3)......  **Adds requirements
                                                     on identification
                                                     of ungrounded
                                                     conductors on
                                                     different systems.
                              1910.304(b)(4)......  **Adds requirements
                                                     for ground fault
                                                     circuit interrupter
                                                     protection.
1910.304(b)(2)..............  1910.304(b)(5),       No significant
                               introductory text.    change.
                              1910.304(b)(5)(i)...  **Adds requirements
                                                     for ratings of
                                                     lampholders.
                              1910.304(b)(5)(ii)..  **Adds requirements
                                                     for ratings of
                                                     receptacles.
                              1910.304(b)(6)......  **Adds requirements
                                                     for receptacles to
                                                     be installed
                                                     wherever cords with
                                                     attachment plugs
                                                     are used.
1910.304(c), introductory     1910.304(c),          No significant
 text.                         introductory text.    change. (The
                                                     requirements in
                                                     existing paragraph
                                                     (c)(5) are placed
                                                     in a separate
                                                     paragraph (d).)
1910.304(c)(1)..............  1910.304(c)(1)......  **Adds a requirement
                                                     for the separation
                                                     of conductors on
                                                     poles.
1910.304(c)(2)..............  1910.304(c)(2)......  Increases the
                                                     minimum clearances
                                                     for new
                                                     installations of
                                                     open conductors and
                                                     service drops to
                                                     match those in NFPA
                                                     70E-2000.
1910.304(c)(3)..............  1910.304(c)(3)(i)...  No substantive
                                                     change. (The
                                                     proposal clarifies
                                                     that paragraph
                                                     (c)(2) applies to
                                                     platforms,
                                                     projections, or
                                                     surfaces from which
                                                     runs of open
                                                     conductors can be
                                                     reached.)

[[Page 17785]]

 
                              1910.304(c)(3)(ii)..  **Adds restrictions
                                                     for installing
                                                     overhead service
                                                     conductors near
                                                     building openings
                                                     through which
                                                     materials may be
                                                     moved.
1910.304(c)(4)..............  1910.304(c)(4)......  **Adds an exception
                                                     to the minimum
                                                     clearance
                                                     requirement for
                                                     conductors attached
                                                     to the side of a
                                                     building. (The
                                                     proposal also
                                                     clarifies that
                                                     paragraph (c)(2)
                                                     applies to roof
                                                     surfaces that are
                                                     subject to
                                                     pedestrian or
                                                     vehicular traffic.)
1910.304(c)(5)..............  1910.304(d).........  No substantive
                                                     change.
1910.304(d)(1)(i)...........  1910.304(e)(1)(i)...  No substantive
                                                     change.
1910.304(d)(1)(ii)..........  1910.304(e)(1)(ii)..  No substantive
                                                     change.
                              1910.304(e)(1)(iii).  **Adds a requirement
                                                     for service
                                                     disconnecting means
                                                     to be suitable for
                                                     the prevailing
                                                     conditions.
1910.304(d)(2)..............  1910.304(e)(2)......  No substantive
                                                     change.
1910.304(e)(1), introductory  1910.304(f)(1),       No substantive
 text.                         introductory text.    change.
1910.304(e)(1)(i)...........  1910.304(f)(1)(i)...  No substantive
                                                     change.
1910.304(e)(1)(ii)..........  1910.304(f)(1)(ii)..  No substantive
                                                     change.
1910.304(e)(1)(iii).........  1910.304(f)(1)(iii).  **The types of
                                                     circuits that are
                                                     allowed to have a
                                                     single switch
                                                     disconnect for
                                                     multiple fuses are
                                                     now specified in
                                                     the standard.
1910.304(e)(1)(iv)..........  1910.304(f)(1)(iv)..  No substantive
                                                     change.
1910.304(e)(1)(v)...........  1910.304(f)(1)(v)...  **Adds a requirement
                                                     to clarify that
                                                     handles of circuit
                                                     breakers and
                                                     similar moving
                                                     parts also need to
                                                     be guarded so that
                                                     they do not injure
                                                     employees.
1910.304(e)(1)(vi)(A).......  1910.304(f)(1)(vi)..  No substantive
                                                     change.
1910.304(e)(1)(vi)(B).......  1910.304(f)(1)(vii).  No substantive
                                                     change.
1910.304(e)(1)(vi)(C).......  1910.304(f)(1)(viii)  **Adds circuit
                                                     breakers used on
                                                     277-volt
                                                     fluorescent
                                                     lighting circuits
                                                     to the types of
                                                     breakers required
                                                     to be marked
                                                     ``SWD.''
                              1910.304(f)(1)(ix)..  **Adds a requirement
                                                     to clarify ratings
                                                     of circuit
                                                     breakers.
1910.304(e)(2)..............  1910.304(f)(2)......  **Adds specific
                                                     requirements on how
                                                     to protect feeders
                                                     and branch circuits
                                                     energized at more
                                                     than 600 volts.
1910.304(f), introductory     1910.304(g),          No substantive
 text.                         introductory text.    change.
1910.304(f)(1), introductory  1910.304(g)(1),       No substantive
 text.                         introductory text.    change.
1910.304(f)(1)(i)...........  1910.304(g)(1)(i)...  No substantive
                                                     change.
1910.304(f)(1)(ii)..........  1910.304(g)(1)(ii)..  No substantive
                                                     change.
1910.304(f)(1)(iii).........  1910.304(g)(1)(iii).  No substantive
                                                     change.
1910.304(f)(1)(iv)..........  1910.304(g)(1)(iv)..  No substantive
                                                     change. (The
                                                     specific voltage
                                                     ratings in existing
                                                     paragraphs
                                                     (g)(1)(iv)(B) and
                                                     (g)(1)(iv)(C) are
                                                     being removed.
                                                     However, this is
                                                     not a substantive
                                                     change as those are
                                                     the voltages used
                                                     in the described
                                                     systems.)
1910.304(f)(1)(v)...........  1910.304(g)(1)(v)...  **Adds an exception
                                                     to the requirement
                                                     to ground systems
                                                     for high-impedance
                                                     grounded systems of
                                                     480 V to 1000 V
                                                     under certain
                                                     conditions.
1910.304(f)(2)..............  ....................  **Removed. The
                                                     hazard is addressed
                                                     in proposed Sec.
                                                     1910.304(a)(1)(i),
                                                     which requires
                                                     conductors used as
                                                     grounded conductors
                                                     to be identifiable
                                                     and distinguishable
                                                     from other
                                                     conductors.
                              1910.304(g)(2)......  **Relaxes
                                                     requirements for
                                                     grounding portable
                                                     and vehicle mounted
                                                     generators so that
                                                     the requirements
                                                     match those in
                                                     OSHA's Construction
                                                     Standards (Sec.
                                                     1926.404(f)(3)).
1910.304(f)(3)..............  1910.304(g)(3)......  No substantive
                                                     change.
1910.304(f)(4)..............  1910.304(g)(4)......  No substantive
                                                     change.
1910.304(f)(5)(i)...........  1910.304(g)(5)(i)...  No substantive
                                                     change.
1910.304(f)(5)(ii)..........  1910.304(g)(5)(ii)..  No substantive
                                                     change.
1910.304(f)(5)(iii).........  1910.304(g)(5)(iii).  No substantive
                                                     change.
1910.304(f)(5)(iv)..........  1910.304(g)(5)(iv)..  **The exceptions for
                              1910.304(g)(5)(v)...   grounding fixed
                                                     equipment operating
                                                     at more than 150 V
                                                     are extended to all
                                                     fixed electric
                                                     equipment
                                                     regardless of
                                                     voltage. Also, the
                                                     proposal includes a
                                                     new exception for
                                                     double-insulated
                                                     equipment.

[[Page 17786]]

 
1910.304(f)(5)(v)...........  1910.304(g)(5)(vi)..  **Adds the following
                              1910.304(g)(5)(vii).   equipment to the
                                                     list of cord- and
                                                     plug-connected
                                                     equipment required
                                                     to be grounded:
                                                     stationary and
                                                     fixed motor-
                                                     operated tools and
                                                     light industrial
                                                     motor-operated
                                                     tools.
1910.304(f)(5)(vi)..........  1910.304(g)(6)......  **Adds frames and
                                                     tracks of
                                                     electrically
                                                     operated hoists to
                                                     the list of
                                                     nonelectrical
                                                     equipment required
                                                     to be grounded.
1910.304(f)(6)..............  1910.304(g)(7)......  No substantive
                                                     change.
1910.304(f)(7)(i)...........  1910.304(g)(8),       No substantive
                               introductory text.    change.
1910.304(f)(7)(ii)..........  1910.304(g)(8)(i)...  No substantive
                                                     change.
1910.304(f)(7)(iii).........  1910.304(g)(8)(ii)..  No substantive
                                                     change.
Sec.   1910.305 Wiring        Sec.   1910.305
 methods, components, and      Wiring methods,
 equipment for general use.    components, and
                               equipment for
                               general use.
1910.305(a), introductory     1910.305(a),          No substantive
 text.                         introductory text.    change.
1910.305(a)(1)(i)...........  1910.305(a)(1)(i)...  **Adds a requirement
                                                     that equipment be
                                                     bonded so as to
                                                     provide adequate
                                                     fault-current-
                                                     carrying
                                                     capability. Also,
                                                     clarifies that
                                                     nonconductive
                                                     coatings need to be
                                                     removed unless the
                                                     fittings make this
                                                     unnecessary.
                              1910.305(a)(1)(ii)..  **Adds an exception
                                                     to the bonding
                                                     requirement for the
                                                     reduction of
                                                     electrical noise.
1910.305(a)(1)(ii)..........  1910.305(a)(1)(iii).  No substantive
                                                     change.
1910.305(a)(2), introductory  1910.305(a)(2),       No substantive
 text.                         introductory text.    change. Removes the
                                                     provision allowing
                                                     temporary wiring to
                                                     be of a class less
                                                     than permanent
                                                     wiring per the 2002
                                                     NEC. The change has
                                                     no substantive
                                                     effect because
                                                     temporary wiring is
                                                     required to meet
                                                     the same
                                                     requirements
                                                     regardless of the
                                                     deleted language.
                                                     (Both the proposal
                                                     and the existing
                                                     standard contain
                                                     the following
                                                     requirement:
                                                     ``Except as
                                                     specifically
                                                     modified in this
                                                     paragraph, all
                                                     other requirements
                                                     of this subpart for
                                                     permanent wiring
                                                     shall apply to
                                                     temporary wiring
                                                     installations.'')
1910.305(a)(2)(i),            1910.305(a)(2)(i),    No substantive
 introductory text.            introductory text.    change.
1910.305(a)(2)(i)(A)........  1910.305(a)(2)(i)(A)  Removes demolition
                                                     from the list of
                                                     activities for
                                                     which temporary
                                                     wiring is permitted
                                                     . Demolition is one
                                                     form of
                                                     construction work,
                                                     which is not
                                                     covered by the
                                                     Subpart S
                                                     installation
                                                     requirements.
1910.305(a)(2)(i)(B)........  1910.305(a)(2)(i)(C)  **Adds emergencies
                                                     to the list of
                                                     activities for
                                                     which temporary
                                                     wiring is
                                                     permitted.
1910.305(a)(2)(i)(C)........  1910.305(a)(2)(i)(B)  No substantive
                                                     change.
                              1910.305(a)(2)(ii)..  **Clarifies that
                                                     temporary wiring
                                                     must be removed
                                                     when the project or
                                                     purpose for which
                                                     it was used has
                                                     been completed.
1910.305(a)(2)(ii)..........  1910.305(a)(2)(iii).  No substantive
                                                     change.
1910.305(a)(2)(iii)(A)......  1910.305(a)(2)(iv)..  **Feeders may now
                                                     only be run as
                                                     single insulated
                                                     conductors when
                                                     accessible to
                                                     qualified employees
                                                     only and used for
                                                     experiments,
                                                     development work,
                                                     or emergencies.
                                                     (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.305(a)(2)(iii)(B)......  1910.305(a)(2)(v)...  No substantive
                                                     change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.305(a)(2)(iii)(C)......  1910.305(a)(2)(vi)..   No substantive
                                                     change.
1910.305(a)(2)(iii)(D)......   1910.305(a)(2)(vii)   No substantive
                                                     change.
1910.305(a)(2)(iii)(E)......   1910.305(a)(2)(viii   **Adds a
                               ).                    requirement that
                                                     disconnecting means
                                                     for a multiwire
                                                     circuit
                                                     simultaneously
                                                     disconnect all
                                                     ungrounded
                                                     conductors of the
                                                     circuit.
1910.305(a)(2)(iii)(F)......   1910.305(a)(2)(ix).   **This provision no
                                                     longer allows
                                                     installing fixtures
                                                     or lampholders more
                                                     than 2.1 meters
                                                     above the working
                                                     surface as a means
                                                     of guarding. Also,
                                                     the proposal adds a
                                                     requirement for
                                                     grounding metal-
                                                     case sockets.
1910.305(a)(2)(iii)(G)......   1910.305(a)(2)(x)..   No substantive
                                                     change.

[[Page 17787]]

 
                              1910.305(a)(2)(xi)..  **Adds requirements
                                                     for cable
                                                     assemblies and
                                                     flexible cords and
                                                     cables to be
                                                     adequately
                                                     supported.
1910.305(a)(3)(i)(A)........   1910.305(a)(3)(i)..   No substantive
                                                     change.
1910.305(a)(3)(i)(B)........   1910.305(a)(3)(ii).   **Adds several
                                                     types of cables and
                                                     single insulated
                                                     conductors to the
                                                     list of types
                                                     permitted in
                                                     industrial
                                                     establishments.
                              1910.305(a)(3)(iii).   **Adds a
                                                     requirement
                                                     limiting the use of
                                                     metallic cable
                                                     trays as an
                                                     equipment grounding
                                                     conductor.
1910.305(a)(3)(i)(C)........   1910.305(a)(3)(iv).   No substantive
                                                     change.
                              1910.305(a)(3)(v)...   **Adds a
                                                     requirement
                                                     limiting the use of
                                                     nonmetallic cable
                                                     trays.
1910.305(a)(3)(ii)..........   1910.305(a)(3)(vi).   No substantive
                                                     change.
1910.305(a)(4)(i)...........   1910.305(a)(4)(i)..   No substantive
                                                     change.
1910.305(a)(4)(ii)..........  1910.305(a)(4)(ii)..  **Adds specific
                                                     support
                                                     requirements for
                                                     conductors smaller
                                                     than No. 8.
1910.305(a)(4)(iii).........   1910.305(a)(4)(iii)   No substantive
                                                     change.
1910.305(a)(4)(iv)..........   1910.305(a)(4)(iv).   No substantive
                                                     change.
1910.305(a)(4)(v)...........   1910.305(a)(4)(v)..   No substantive
                                                     change.
1910.305(b)(1)..............  1910.305(b)(1)(i)...  No substantive
                              1910.305(b)(1)(ii)..   change. (Individual
                              1910.305(b)(1)(iii).   requirements are
                                                     placed in separate
                                                     paragraphs.)
                                                    **Adds requirements
                                                     for supporting
                                                     cables entering
                                                     cabinets, cutout
                                                     boxes, and meter
                                                     sockets.
1910.305(b)(2)..............  1910.305(b)(2)(i)...  No substantive
                                                     change.
                              1910.305(b)(2)(ii)..  **Adds a requirement
                                                     for any exposed
                                                     edge of a
                                                     combustible ceiling
                                                     finish at a fixture
                                                     canopy or pan to be
                                                     covered with
                                                     noncombustible
                                                     material.
1910.305(b)(3)..............  1910.305(b)(3)......  No substantive
                                                     change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.305(c)(1)..............  1910.305(c)(1)......  No substantive
                              1910.305(c)(2)......   change.
                              1910.305(c)(3)(i)...
                              1910.305(c)(3)(ii)..  **Adds a requirement
                                                     for load terminals
                                                     on switches to be
                                                     deenergized when
                                                     the switches are
                                                     open except under
                                                     limited
                                                     circumstances.
                              1910.305(c)(4)......  **Adds a specific
                                                     requirement for
                                                     flush-mounted
                                                     switches to have
                                                     faceplates that
                                                     completely cover
                                                     the opening and
                                                     that seat against
                                                     the finished
                                                     surface.
1910.305(c)(2)..............  1910.305(c)(5)......  **Adds a requirement
                                                     to ground
                                                     faceplates for snap
                                                     switches.
1910.305(d).................  1910.305(d)(1)......  No substantive
                              1910.305(d)(2)......   change. (Individual
                              1910.305(d)(3)......   requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.305(e)(1)..............  1910.305(e)(1)......  **Adds a requirement
                                                     for metallic
                                                     cabinets, cutout
                                                     boxes, fittings,
                                                     boxes, and
                                                     panelboard
                                                     enclosures
                                                     installed in damp
                                                     or wet locations to
                                                     have an air space
                                                     between the
                                                     enclosure and the
                                                     mounting surface.
1910.305(e)(2)..............  1910.305(e)(2)......  No substantive
                                                     change.
1910.305(f).................  1910.305(f)(1)......  No substantive
                              1910.305(f)(2)......   change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.305(g)(1)(i)...........  1910.305(g)(1)(i)...  **Adds the following
                              1910.305(g)(1)(ii)..   to the types of
                                                     connections
                                                     permitted for
                                                     flexible cords and
                                                     cables: portable
                                                     and mobile signs
                                                     and connection of
                                                     moving parts. The
                                                     proposal also
                                                     clarifies that
                                                     flexible cords and
                                                     cables may be used
                                                     for temporary
                                                     wiring as permitted
                                                     in Sec.
                                                     1910.305(a)(2).
1910.305(g)(1)(ii)..........  1910.305(g)(1)(iii).  No substantive
                                                     change.
1910.305(g)(1)(iii).........  1910.305(g)(1)(iv)..  No substantive
                                                     change. (Clarifies
                                                     that flexible cords
                                                     and cables may not
                                                     be installed inside
                                                     raceways.)
1910.305(g)(1)(iv)..........  1910.305(g)(1)(v)...  **Permits additional
                                                     cord types to be
                                                     used in show
                                                     windows and show
                                                     cases.
1910.305(g)(2)(i)...........  1910.305(g)(2)(i)...  **Adds new types of
                                                     cords to the list
                                                     of those that must
                                                     be marked with
                                                     their type
                                                     designation.

[[Page 17788]]

 
1910.305(g)(2)(ii)..........  1910.305(g)(2)(ii)..  **Changed the
                                                     minimum size of
                                                     hard service and
                                                     junior hard service
                                                     cords that may be
                                                     spliced from No. 12
                                                     to 14.
1910.305(g)(2)(iii).........  1910.305(g)(2)(iii).  No substantive
                                                     change.
1910.305(h).................  1910.305(h).........  **Permits the
                              1910.305(h)(1)......   minimum size of the
                              1910.305(h)(2)......   insulated ground-
                              1910.305(h)(3)......   check conductor of
                              1910.305(h)(6)......   Type G-GC cables to
                              1910.305(h)(7)......   be No. 10 rather
                              1910.305(h)(8)......   than No. 8.
                              1910.305(h)(4)......   **Adds a
                                                     requirement for
                                                     shields to be
                                                     grounded.
                              1910.305(h)(5)......   **Adds minimum
                                                     bending radii
                                                     requirements for
                                                     portable cables.
1910..305(i)(1).............  1910.305(i)(1)......  No substantive
                                                     change.
1910.305(i)(2)..............   1910.305(i)(2).....   No substantive
                                                     change.
1910.305(i)(3)..............   1910.305(i)(3).....   **Also permits
                                                     fixture wire to be
                                                     used in fire alarm
                                                     circuits.
1910.305(j)(1)(i)...........   1910.305(j)(1)(i)..   No substantive
                                                     change.
1910.305(j)(1)(ii)..........   1910.305(j)(1)(ii).   No substantive
                                                     change. (Clarifies
                                                     that metal-shell
                                                     paper-lined
                                                     lampholders may not
                                                     be used for
                                                     handlamps.)
1910.305(j)(1)(iii).........   1910.305(j)(1)(iii)   **Adds a
                                                     requirement that
                                                     the grounded
                                                     circuit conductor,
                                                     where present, be
                                                     connected to the
                                                     screw shell.
1910.305(j)(1)(iv)..........   1910.305(j)(1)(iv).   No substantive
                                                     change.
                              1910.305(j)(2)(i)...   **Adds requirements
                                                     to ensure that
                                                     attachment plugs
                                                     and connectors have
                                                     no exposed live
                                                     parts.
1910.305(j)(2)(i)...........   1910.305(j)(2)(ii).   No substantive
                                                     change.
                              1910.305(j)(2)(iii).   **Clarifies that
                                                     nongrounding-type
                                                     receptacles may not
                                                     be used with
                                                     grounding-type
                                                     attachment plugs.
1910.305(j)(2)(ii)..........   1910.305(j)(2)(iv).   No substantive
                                                     change.
                              1910.305(j)(2)(v)...  **Adds requirements
                              1910.305(j)(2)(vi)..   for receptacles
                              1910.305(j)(2)(vii).   outdoors to be
                                                     installed in
                                                     weatherproof
                                                     enclosures
                                                     appropriate for the
                                                     use of the
                                                     receptacle and for
                                                     the location.
1910.305(j)(3)(i)...........   1910.305(j)(3)(i)..   No substantive
                                                     change.
1910.305(j)(3)(ii)..........   1910.305(j)(3)(ii).   **Adds a
                                                     requirement to
                                                     group and identify
                                                     disconnecting means
                                                     for appliances
                                                     supplied by more
                                                     than one source.
1910.305(j)(3)(iii).........   1910.305(j)(3)(iii)   **Adds requirements
                                                     for marking
                                                     frequency and
                                                     required external
                                                     overload protection
                                                     for appliances.
                              1910.305(j)(3)(iv)..   **Clarifies that
                                                     markings must be
                                                     visible or easily
                                                     accessible after
                                                     installation.
1910.305(j)(4)..............   1910.305(j)(4).....   No substantive
                                                     change.
1910.305(j)(4)(i)...........   1910.305(j)(4)(i)..   No substantive
                                                     change.
1910.305(j)(4)(ii)(A).......   1910.305(j)(4)(ii).   No substantive
                                                     change.
1910.305(j)(4)(ii)(B).......   1910.305(j)(4)(iii)   No substantive
                                                     change.
1910.305(j)(4)(ii)(C).......  ....................   Removed. All
                                                     disconnecting means
                                                     must be capable of
                                                     being locked in the
                                                     open position by
                                                     Sec.  Sec.
                                                     1910.302(c) and
                                                     1910.303(f)(4).
1910.305(j)(4)(ii)(D).......   1910.305(j)(4)(iv).   No substantive
                                                     change.
1910.305(j)(4)(ii)(E).......   1910.305(j)(4)(v)..   No substantive
                                                     change.
1910.305(j)(4)(ii)(F).......   1910.305(j)(4)(vi).   No substantive
                                                     change.
1910.305(j)(4)(iii).........   1910.305(j)(4)(vii)   No substantive
                                                     change.
1910.305(j)(4)(iv)(A).......  ....................   Removed. Covered by
                                                     Sec.
                                                     1910.303(g)(2),
                                                     (h)(2), and (h)(5).
1910.305(j)(4)(iv)(B).......   1910.305(j)(4)(viii   No substantive
                               ).                    change.
1910.305(j)(5)(i)...........   1910.305(j)(5)(i)..   No substantive
                                                     change.
1910.305(j)(5)(ii)..........   1910.305(j)(5)(ii).   No substantive
                                                     change.
1910.305(j)(5)(iii).........   1910.305(j)(5)(iii)   No substantive
                                                     change.
1910.305(j)(5)(i)(iv).......   1910.305(j)(5)(i)(i   No substantive
                               v).                   change. (Oil-
                                                     insulated
                                                     transformers
                                                     installed indoors
                                                     are presumed to
                                                     present a hazard to
                                                     employees, and lack
                                                     of employee
                                                     exposure to a
                                                     hazard is an
                                                     affirmative
                                                     defense.)
1910.305(j)(5)(i)(v)........   1910.305(j)(5)(i)(v   No substantive
                               ).                    change.
1910.305(j)(5)(i)(vi).......   1910.305(j)(5)(i)(v   No substantive
                               i).                   change.

[[Page 17789]]

 
1910.305(j)(5)(i)(vii)......   1910.305(j)(5)(i)(v   No substantive
                               ii).                  change.
1910.305(j)(5)(i)(viii).....   1910.305(j)(5)(i)(v   No substantive
                               iii).                 change.
1910.305(j)(6)(i)...........   1910.305(j)(6)(i)..   No substantive
                                                     change.
1910.305(j)(6)(ii),           1910.305(j)(6)(ii),    No substantive
 introductory text.            introductory text.    change.
                              1910.305(j)(6)(ii)(A   **Adds requirements
                               ).                    to provide
                              1910.305(j)(6)(ii)(B   disconnecting means
                               ).                    of adequate
                                                     capacity for
                                                     capacitors
                                                     operating at more
                                                     than 600 V.
1910.305(j)(6)(ii)(A).......   *1910.305(j)(6)(ii)  No substantive
                               (C).                  change.
1910.305(j)(6)(ii)(B).......   1910.305(j)(6)(ii)(   No substantive
                               D).                   change.
1910.305(j)(7)..............   1910.305(j)(7).....   No substantive
                                                     change.
Sec.   1910.306 Specific      Sec.   1910.306
 purpose equipment and         Specific purpose
 installations..               equipment and
                               installations..
1910.306(a)(1)..............  1910.306(a)(1)(i)...  **Reorganized and
                              1910.306(a)(2)(i)...   clarified the
                              1910.306(a)(2)(ii)..   requirements for
                                                     disconnecting means
                                                     for signs. The
                                                     proposal does not
                                                     apply these
                                                     requirements to
                                                     exit signs.
1910.306(a)(2)..............   1910.306(a)(2)(iii)   No substantive
                                                     change.
1910.306(b), introductory      1910.306(b),         No substantive
 text.                         introductory text.    change.
1910.306(b)(1)(i)...........   1910.306(b)(1).....   **Adds specific
                                                     requirements for
                                                     the type and
                                                     location of
                                                     disconnecting means
                                                     for runway
                                                     conductors.
1910.306(b)(1)(ii)..........   1910.306(b)(2).....   No substantive
                                                     change. (The
                                                     requirements are
                                                     being reorganized.)
1910.306(b)(2)..............   1910.306(b)(3).....   No substantive
                                                     change.
1910.306(b)(3)..............   1910.306(b)(4).....   No substantive
                                                     change.
1910.306(c).................   1910.306(c),         **This paragraph now
                               introductory text.    covers wheelchair
                                                     lifts, and stairway
                                                     chair lifts.
1910.306(c)(1)..............   1910.306(c)(1).....   No substantive
                                                     change.
1910.306(c)(2)..............   1910.306(c)(8).....   No substantive
                                                     change.
1910.306(c)(3)..............   1910.306(c)(2).....   No substantive
                                                     change.
                              1910.306(c)(3)......   **Adds requirements
                                                     for the type of
                                                     disconnecting
                                                     means.
                              11910.306(c)(4).....   **Adds requirements
                                                     for the operation
                                                     of disconnecting
                                                     means.
                              1910.306(c)(5)......  **Adds requirements
                                                     for the location of
                                                     disconnecting
                                                     means.
                              1910.306(c)(6)......  **Adds requirements
                                                     for the
                                                     identification of
                                                     disconnecting
                                                     means.
                              1910.306(c)(7)......  **Adds requirements
                                                     for disconnecting
                                                     means for single
                                                     car and multicar
                                                     installations
                                                     supplied by more
                                                     than one source.
                              1910.306(c)(9)......  **Adds requirements
                                                     for warning signs
                                                     for interconnected
                                                     multicar
                                                     controllers.
                              1910.306(c)(10).....  **Adds exceptions
                                                     related to the
                                                     location of motor
                                                     controllers.
1910.306(d)(1)..............  1910.306(d)(1)......  **Adds requirements
                                                     for the type and
                                                     rating of the
                                                     disconnecting
                                                     means.
1910.306(d)(2)..............  1910.306(d)(2)......  Clarifies that a
                                                     supply circuit
                                                     switch may be used
                                                     as a disconnecting
                                                     means if the
                                                     circuit supplies
                                                     only one welder.
1910.306(e).................  1910.306(e).........  **Adds a requirement
                                                     to group the
                                                     disconnecting means
                                                     for the HVAC
                                                     systems serving
                                                     information
                                                     technology rooms
                                                     with the
                                                     disconnecting means
                                                     for the information
                                                     technology
                                                     equipment. (The
                                                     existing standard
                                                     refers to this
                                                     equipment as data
                                                     processing
                                                     equipment.)
1910.306(f), introductory     1910.306(f),          **Adds coverage of X-
 text.                         introductory text.    rays for dental or
                                                     medical use.
1910.306(f)(1)(i)...........  1910.306(f)(1)(i)...  No substantive
                                                     change.
1910.306(f)(1)(ii)..........  1910.306(f)(1)(ii)..  No substantive
                                                     change.
1910.306(f)(2)(i)...........  1910.306(f)(2)(i)...  No substantive
                                                     change.
1910.306(f)(2)(ii)..........  1910.306(f)(2)(ii)..  No substantive
                                                     change.
1910.306(g)(1)..............  1910.306(g),          No substantive
                               introductory text.    change.
1910.306(g)(2)(i)...........  1910.306(g)(1)(i)...  No substantive
                                                     change.
1910.306(g)(2)(ii)..........  1910.306(g)(1)(ii)..  No substantive
                                                     change.
1910.306(g)(2)(iii).........  1910.306(g)(1)(iii).  **Adds a requirement
                                                     for the
                                                     installation of
                                                     doors or detachable
                                                     panels to provide
                                                     access to internal
                                                     parts. Adds a
                                                     requirement that
                                                     detachable panels
                                                     not be readily
                                                     removable.
1910.306(g)(2)(iv)..........  1910.306(g)(1)(iv)..  No substantive
                                                     change.

[[Page 17790]]

 
1910.306(g)(2)(v)...........  1910.306(g)(1)(v)...  No substantive
                                                     change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.306(g)(2)(vi)..........  1910.306(g)(1)(vi)..  **Adds a requirement
                                                     to ensure adequate
                                                     rating of
                                                     disconnecting
                                                     means. The proposal
                                                     also clarifies when
                                                     the supply circuit
                                                     disconnecting means
                                                     may be used as the
                                                     disconnecting means
                                                     for induction and
                                                     dielectric heating
                                                     equipment.
1910.306(g)(3)..............  1910.306(g)(2)......  No substantive
                                                     change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.306(h)(1)..............  1910.306(h),          No substantive
                               introductory text.    change.
1910.306(h)(2)..............  1910.306(h)(1)......  No substantive
                                                     change.
1910.306(h)(3)..............  1910.306(h)(2)......  No substantive
                                                     change.
1910.306(h)(4)(i)...........  1910.306(h)(3)......  No substantive
1910.306(h)(4)(ii)..........                         change. (The two
                                                     provisions are
                                                     combined into one
                                                     paragraph.)
1910.306(h)(5)(i)...........  1910.306(h)(4)(i)...  No substantive
                                                     change.
1910.306(h)(5)(ii)..........  1910.306(h)(4)(ii)..  No substantive
                                                     change.
1910.306(h)(6)(i)...........  1910.306(h)(5)(i)...  **Adds requirements
                                                     limiting primary
                                                     and secondary
                                                     voltage on
                                                     isolating
                                                     transformers
                                                     supplying
                                                     receptacles for
                                                     ungrounded cord-
                                                     and plug-connected
                                                     equipment. Also,
                                                     adds requirement
                                                     for overcurrent
                                                     protection for
                                                     circuits supplied
                                                     by these
                                                     transformers.
1910.306(h)(6)(ii)..........  1910.306(h)(5)(ii)..  No substantive
                                                     change.
1910.306(h)(6)(iii).........  1910.306(h)(5)(iii).  No substantive
                                                     change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.306(h)(7)(i)...........  1910.306(h)(6)(i)...  No substantive
1910.306(h)(7)(ii)..........                         change.
1910.306(h)(7)(iii).........  1910.306(h)(6)(ii)..  No substantive
                                                     change.
1910.306(h)(7)(iv)..........  1910.306(h)(6)(iii).  No substantive
                                                     change.
1910.306(h)(8)..............  1910.306(h)(7)......  No substantive
                                                     change.
1910.306(h)(9)(i)...........  1910.306(h)(8)(i)...  No substantive
                                                     change.
1910.306(h)(9)(ii)..........  1910.306(h)(8)(ii)..  No substantive
                                                     change.
1910.306(i)(1)..............  1910.306(i)(1)......  No substantive
                                                     change.
1910.306(i)(2)..............  1910.306(i)(2)......  **Allows the
                                                     disconnecting means
                                                     for a center pivot
                                                     irrigation machine
                                                     to be located not
                                                     more than 15.2 m
                                                     (50 ft) from the
                                                     machine if the
                                                     disconnecting means
                                                     is visible from the
                                                     machine.
                                                     (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.306(j)(1)..............  1910.306(j),          **Clarifies that
                               introductory text.    hydro-massage
                                                     bathtubs are
                                                     covered by this
                                                     paragraph.
1910.306(j)(2)(i)...........  1910.306(j)(1)(i)...  No substantive
                                                     change.
                              1910.306(j)(1)(ii)..  **Extends the
                                                     boundary within
                                                     which receptacles
                                                     require GFCI
                                                     protection from
                                                     4.57 m (15 ft) to
                                                     6.08 m (20 ft) for
                                                     new installations.
                              1910.306(j)(1)(iii).  **Adds requirements
                                                     for the
                                                     installation of at
                                                     least one
                                                     receptacle near
                                                     permanently
                                                     installed pools at
                                                     dwelling units.
1910.306(j)(2)(ii)(A).......  1910.306(j)(2)(i)...  **Clarifies that
                                                     ceiling suspended
                                                     (paddle) fans are
                                                     covered by this
                                                     requirement.
1910.306(j)(2)(ii)(B).......  1910.306(j)(2)(ii)..  No substantive
                                                     change.
1910.306(j)(3)..............  1910.306(j)(3)......  No substantive
                                                     change.
1910.306(j)(4)(i)...........  1910.306(j)(4)(i)...  No substantive
                                                     change.
1910.306(j)(4)(ii)..........  1910.306(j)(4)(ii)..  No substantive
                                                     change.
                              1910.306(j)(4)(iii).  **Adds a requirement
                                                     to guard lighting
                                                     fixtures facing
                                                     upward.
1910.306(j)(5)..............  1910.306(j)(5)......  No substantive
                                                     change.
                              1910.306(k).........  **Adds requirements
                                                     for carnivals,
                                                     circuses, fairs,
                                                     and similar events.
Sec.   1910.307 Hazardous     Sec.   1910.307
 (classified) locations..      Hazardous
                               (classified)
                               locations..
Sec.   1910.307(a)..........  1910.307(a).........  **Adds the Zone
                                                     classification
                                                     system for Class I
                                                     locations. (See
                                                     detailed discussion
                                                     later in this
                                                     section of the
                                                     preamble.)
                              1910.307(b).........  **Adds documentation
                                                     requirements for
                                                     hazardous locations
                                                     classified using
                                                     either the division
                                                     or zone
                                                     classification
                                                     system.
1910.307(b), introductory     1910.307(c),          No substantive
 text.                         introductory text.    change.
1910.307(b)(1)..............  1910.307(c)(1)......  No substantive
                                                     change.
1910.307(b)(2)(i)...........  1910.307(c)(2)(i)...  No substantive
                                                     change.
1910.307(b)(2)(i)(ii),        1910.307(c)(2)(ii),   No substantive
 introductory text.            introductory text.    change.
1910.307(b)(2)(ii)(A).......  1910.307(c)(2)(ii)(A  No substantive
                               ).                    change.

[[Page 17791]]

 
1910.307(b)(2)(ii)(B).......  1910.307(c)(2)(ii)(B  **Also permits
                               ).                    fixtures approved
                                                     for Class II,
                                                     Division 2
                                                     locations to omit
                                                     the group marking.
1910.307(b)(2)(ii)(C).......  1910.307(c)(2)(ii)(C  No substantive
                               ).                    change.
1910.307(b)(2)(ii)(D).......  1910.307(c)(2)(ii)(D  No substantive
                               ).                    change.
                              1910.307(c)(2)(ii)(E  **Adds a requirement
                               ).                    that electric
                                                     equipment suitable
                                                     for an ambient
                                                     temperature
                                                     exceeding 40EC
                                                     (104EF) be marked
                                                     with the maximum
                                                     ambient
                                                     temperature.
1910.307(b)(3)..............  1910.307(c)(3)......  No substantive
                                                     change.
1910.307(b)(3), Note........  1910.307(c)(3), Note  The last sentence of
                                                     the note is removed
                                                     to make it clear
                                                     that the OSHA
                                                     standard does not
                                                     incorporate the
                                                     National Electrical
                                                     Code by reference.
                                                     The NEC continues
                                                     to be a guideline
                                                     that employers may
                                                     follow in
                                                     determining the
                                                     type and design of
                                                     equipment and
                                                     installations that
                                                     will meet the OSHA
                                                     standard.
1910.307(c).................  1910.307(d).........  No substantive
                                                     change.
1910.307(d).................  1910.307(e).........  No substantive
                                                     change.
                              1910.307(f).........  **The proposal lists
                                                     the specific
                                                     protective
                                                     techniques for
                                                     electrical
                                                     installations in
                                                     hazardous locations
                                                     classified under
                                                     the division
                                                     classification
                                                     system.
                              1910.307(g).........  **Adds the zone
                                                     classification
                                                     system as an
                                                     alternative method
                                                     of installing
                                                     electric equipment
                                                     in hazardous
                                                     locations. This
                                                     paragraph sets the
                                                     protective
                                                     techniques and
                                                     other requirements
                                                     necessary for safe
                                                     installation of
                                                     electric equipment
                                                     in hazardous
                                                     locations
                                                     classified under
                                                     the zone
                                                     classification
                                                     system. (See
                                                     detailed discussion
                                                     later in this
                                                     section of the
                                                     preamble.)
Sec.   1910.308 Special       Sec.   1910.308
 systems.                      Special systems
1910.308(a), introductory     1910.308(a),          No substantive
 text.                         introductory text.    change.
1910.308(a)(1)(i)...........  1910.308(a)(1)(i)...  **Adds the following
                              1910.308(a)(3)(ii)..   wiring methods to
                                                     those acceptable
                                                     for installations
                                                     operating at more
                                                     than 600 V:
                                                     electrical metallic
                                                     tubing, rigid
                                                     nonmetallic
                                                     conduit, busways,
                                                     and cable bus. The
                                                     proposal also
                                                     removes the
                                                     specific
                                                     requirement to
                                                     support cables
                                                     having a bare lead
                                                     sheath or a braided
                                                     outer covering in a
                                                     manner to prevent
                                                     damage to the braid
                                                     or sheath. This
                                                     hazard is covered
                                                     by Sec.
                                                     1910.303(b)(1) and
                                                     (b)(8)(i) and new
                                                     Sec.
                                                     1910.308(a)(4).
1910.308(a)(1)(ii)..........  1910.308(a)(1)(ii)..  No substantive
                                                     change.
                              1910.308(a)(2)......  **Adds requirements
                              1910.308(a)(3)(i)...   to ensure that high-
                                                     voltage cables can
                                                     adequately handle
                                                     the voltage
                                                     stresses placed
                                                     upon them and to
                                                     ensure that any
                                                     coverings are flame
                                                     retardant.
                              1910.308(a)(4)......  **Adds requirements
                                                     for the protection
                                                     of high-voltage
                                                     cables against
                                                     moisture and
                                                     physical damage
                                                     where the cable
                                                     conductors emerge
                                                     from a metal
                                                     sheath.
1910.308(a)(2)(i)...........  1910.308(a)(5)(i)...  No substantive
                                                     change.
                              1910.308(a)(5)(ii)..  **Adds requirements
                                                     for fuses to
                                                     protect each
                                                     ungrounded
                                                     conductor, for
                                                     adequate ratings of
                                                     fuses installed in
                                                     parallel, and for
                                                     the protection of
                                                     employees from
                                                     power fuses of the
                                                     vented type.
1910.308(a)(2)(ii)..........  1910.308(a)(5)(iii).  **Clarifies that
                                                     distribution
                                                     cutouts are not
                                                     suitable for
                                                     installation in
                                                     buildings or
                                                     transformer vaults.
                              1910.308(a)(5)(iv)..  **Adds requirements
                                                     for fused cutouts
                                                     to either be
                                                     capable of
                                                     interrupting load
                                                     current or be
                                                     supplemented by a
                                                     means of
                                                     interrupting load
                                                     current. In
                                                     addition, a warning
                                                     sign would be
                                                     required for fused
                                                     cutouts that cannot
                                                     interrupt load
                                                     current.

[[Page 17792]]

 
                              1910.308(a)(5)(v)...  **Adds a requirement
                                                     for guarding
                                                     nonshielded cables
                                                     and energized parts
                                                     of oil-filled
                                                     cutouts.
                              1910.308(a)(5)(vi)..  **Adds requirements
                                                     to ensure that load
                                                     interrupting
                                                     switches will be
                                                     protected against
                                                     interrupting fault
                                                     current and to
                                                     provide for warning
                                                     signs for backfed
                                                     switches.
1910.308(a)(2)(iii).........  1910.308(a)(5)(vii).  No substantive
                                                     change.
1910.308(a)(3)(i)...........  1910.308(a)(6)(i)...  No substantive
                                                     change.
1910.308(a)(3)(ii)..........  1910.308(a)(6)(ii)..  No substantive
                                                     change.
1910.308(a)(4)(i)...........  1910.308(a)(7),       No substantive
                               introductory text..   change.
1910.308(a)(4)(ii)..........  1910.308(a)(7)(i)...  No substantive
                              1910.308(a)(7)(iii).   change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
                              1910.308(a)(7)(ii)..  **Clarifies that
                                                     multiconductor
                                                     portable cable may
                                                     supply mobile
                                                     equipment.
1910.308(a)(4)(iii).........  1910.308(a)(7)(iv)..  No substantive
                              1910.308(a)(7)(v)...   change. (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
                              1910.308(a)(7)(vi)..  **Limits the
                                                     conditions under
                                                     which switch or
                                                     contactor
                                                     enclosures may be
                                                     used as junction
                                                     boxes or raceways.
1910.308(a)(4)(iv)..........  1910.308(a)(7)(vii).  No substantive
                                                     change.
1910.308(a)(4)(v)...........  1910.308(a)(7)(viii)  No substantive
                                                     change.
1910.308(b)(1)..............  1910.308(b),          No substantive
                               introductory text.    change.
1910.308(b)(2)..............  1910.308(b)(1)......  No substantive
                                                     change.
1910.308(b)(3)..............  1910.308(b)(2)......  **Clarifies that
                                                     emergency
                                                     illumination
                                                     includes all
                                                     required means of
                                                     egress lighting,
                                                     illuminated exit
                                                     signs, and all
                                                     other lights
                                                     necessary to
                                                     provide required
                                                     illumination.
                              1910.308(b)(3)......  **Adds requirements
                                                     to provide signs
                                                     indicating the
                                                     presence and
                                                     location of on-site
                                                     emergency power
                                                     sources under
                                                     certain conditions.
1910.308(c)(1), introductory  1910.308(c)(1),       No substantive
 text.                         introductory text.    change.
1910.308(c)(1)(i)...........  1910.308(c)(1)(i)...  **Clarifies the
1910.308(c)(1)(ii)..........  1910.308(c)(1)(ii)..   definitions of
1910.308(c)(1)(iii).........  1910.308(c)(1)(iii).   Class 1, 2, and 3
                                                     remote control,
                                                     signaling, and
                                                     power-limited
                                                     circuits based on
                                                     equipment listing.
1910.308(c)(2)..............  1910.308(c)(2)......  No substantive
                                                     change.
                              1910.308(c)(3)......  **Adds requirements
                                                     for the separation
                                                     of cables and
                                                     conductors of Class
                                                     2 and Class 3
                                                     circuits from
                                                     cables and
                                                     conductors of other
                                                     types of circuits.
1910.308(d)(1)..............  1910.308(d)(1)......  No substantive
                                                     change.
1910.308(d)(2), introductory  1910.308(d)(2),       No substantive
 text.                         introductory text.    change.
1910.308(d)(2)(i)...........  1910.308(d)(2)(i)...  No substantive
                                                     change.
1910.308(d)(2)(ii)..........  1910.308(d)(2)(ii)..  **Adds a requirement
                                                     for power-limited
                                                     fire alarm circuit
                                                     power sources to be
                                                     listed and marked
                                                     as such.
1910.308(d)(3)..............  1910.308(d)(3)(i)...  No substantive
                                                     change.
1910.308(d)(4)..............  1910.308(d)(3)(ii)..  **Clarifies the
                              1910.308(d)(3)(iii).   requirements for
                              1910.308(d)(3)(iv)..   installing power-
                                                     limited fire-
                                                     protective
                                                     signaling circuits
                                                     with other types of
                                                     circuits.
                                                     (Individual
                                                     requirements are
                                                     placed in separate
                                                     paragraphs.)
1910.308(d)(5)..............  1910.308(d)(4)......  No substantive
                                                     change.
1910.308(e)(1)..............  1910.308(e),          No substantive
                               introductory text.    change.
1910.308(e)(2)..............  1910.308(e)(1)......  **Clarifies the
                                                     requirement for
                                                     listed primary
                                                     protectors to make
                                                     it clear that
                                                     circuits confined
                                                     within a block do
                                                     not need
                                                     protectors.
1910.308(e)(3)(i)...........  1910.308(e)(2)(i)...  No substantive
                              1910.308(e)(2)(ii)..   change.
1910.308(e)(3)(ii)..........  1910.308(e)(2)(iii).  No substantive
                                                     change.
1910.308(e)(3)(iii).........  1910.308(e)(2)(iv)..  No substantive
                                                     change.
1910.308(e)(4)..............  1910.308(e)(3)......  No substantive
                                                     change.
1910.308(e)(5)(i)...........  1910.308(e)(4)(i)...  No substantive
                                                     change.
1910.308(e)(5)(ii)..........  1910.308(e)(4)(ii)..  No substantive
                                                     change.
1910.308(e)(5)(iii).........  1910.308(e)(4)(iii).  No substantive
                                                     change.
                              1910.308(f).........  **Adds requirements
                                                     to separate
                                                     conductors of solar
                                                     photovoltaic
                                                     systems from
                                                     conductors of other
                                                     systems and to
                                                     provide a
                                                     disconnecting means
                                                     for solar
                                                     photovoltaic
                                                     systems.

[[Page 17793]]

 
                              1910.308(g).........  **Adds an exception
                                                     to the provisions
                                                     on the location of
                                                     overcurrent
                                                     protective devices
                                                     for integrated
                                                     electrical systems.
 
------------------------------------------------------------------------
Note to table:
**These new and revised provisions are included in the 2000 edition of
  NFPA 70E standard. The NFPA 70E Committee believes that these
  provisions, which were taken from the 1999 NEC, are essential to
  employee safety. OSHA agrees with the consensus of NFPA's expert
  opinion that these requirements are reasonably necessary to protect
  employees and has included them in the proposed rule. On occasion,
  OSHA has rewritten the provision to lend greater clarity to its
  requirements. However, these editorial changes to the language of NFPA
  70E do not represent substantive differences. NFPA's handling of these
  provisions and the rationale underpinning them is a matter of public
  record for the NEC and NFPA 70E. OSHA agrees with the rationale in
  this record as it pertains to the new and revised provisions the
  Agency is proposing. OSHA has placed the public record on all editions
  of the NEC and NFPA 70E after 1978 into the public docket for this
  rulemaking.

D. Branch Circuits-Ground Fault Circuit Interrupters for Employees

    Introduction. Each year many employees suffer electric shocks while 
using portable electric tools and equipment. The nature of the injuries 
ranges from minor burns to electrocution. Electric shocks produced by 
alternating currents of power line frequency passing through the body 
of an average adult from hand to foot for 1 second can cause various 
effects, starting from a condition of being barely perceptible at 1 
milliampere to loss of voluntary muscular control from 9 to 25 
milliamperes. The passage of still higher currents can produce 
ventricular fibrillation of the heart from 75 milliamperes to 4 amperes 
and, finally, immediate cardiac arrest at over 4 amperes. These 
injuries occur when employees contact electrically energized parts. 
Typically, the frame of a tool becomes accidentally energized because 
of an electrical fault that provides a conductive path to the tool 
casing. When the employee contacts the tool casing, the fault current 
flows through the employee to ground. The amount of current that flows 
through an employee depends, primarily, upon the resistance of the 
fault within the tool, the resistance of the employee, and the 
resistance of the path from the employee back to the electric power 
supply. Moisture in the atmosphere can contribute to the electrical 
fault by intensifying both the conductive path within the tool and the 
external path back to the electric power supply. Dry skin can have a 
resistance range of about 500 to 500,000 ohms and wet skin can have a 
resistance range of about 200 to 20,000, depending on several factors, 
such as the weight of the employee. Thus, more current will flow if the 
employee is perspiring or becomes wet because of environmental 
conditions.
    One method of protection against injuries from electric shock is 
the ground-fault circuit interrupter (GFCI). This device continually 
monitors the current flow to and from electric equipment. If the 
current going out of the equipment differs by 0.005 amperes from the 
current returning, then the GFCI will deenergize the equipment within 
as little as 25 milliseconds, quickly enough to prevent electrocution.
    GFCI requirements. Proposed Sec.  1910.304(b)(4) would set new 
requirements for ground-fault circuit interrupter protection of 
receptacles and cord connectors used in general industry. As noted 
earlier, this provision would only apply to installations made after 
the effective date of the final rule. Paragraph (b)(4)(i) would require 
ground-fault circuit protection for 125-volt, single-phase, 15- and 20-
ampere receptacles installed in bathrooms and on rooftops. Cord- and 
plug-connected equipment in these locations can get wet and expose 
employees to severe ground-fault hazards. The NFPA 70E Committee 
believes, and OSHA agrees, that using 125-volt, 15- and 20-ampere cord- 
and plug-connected equipment in these locations exposes employees to a 
risk of electrocution great enough to warrant the protection afforded 
by ground-fault circuit interrupters.
    Paragraph (b)(4)(ii) would require ground-fault circuit interrupter 
protection for receptacles on temporary wiring installations that are 
used during maintenance, remodeling, or repair of buildings, 
structures, or equipment, or during similar activities. However, 
receptacles on a 2-wire, single-phase portable or vehicle-mounted 
generator rated not more than 5 kW would be permitted without ground-
fault circuit-interrupter protection if the circuit conductors of the 
generator are insulated from the generator frame and all other grounded 
surfaces.
    OSHA currently requires GFCI protection for 120-volt, 15- and 20-
ampere temporary receptacle outlets used on construction sites (Sec.  
1926.404(b)(1)). In the 26 years that this requirement has been in 
effect, the Agency estimates that between 500 and 750 lives have been 
saved because of it.\15\ Temporary wiring associated with construction-
like activities exposes employees to the same ground-fault hazards as 
those associated with temporary receptacle outlets on construction 
sites. In Sec.  1910.304(b)(4)(ii), OSHA is proposing to extend this 
requirement to temporary receptacles used in construction-like activity 
performed in general industry. The proposal would extend protection to 
receptacles of higher voltage and current ratings. This will better 
protect employees from ground-fault hazards than the construction rule 
because it covers other equipment that is just as subject to damage as 
120-volt, 15- and 20-ampere equipment and that is more prevalent today 
than when the construction rule was promulgated.
---------------------------------------------------------------------------

    \15\ In the preamble to the final rule adopting a requirement 
for GFCIs on construction sites, OSHA estimated that there were 
between 30 and 45 deaths per year caused by 120-volt ground faults 
on construction sites, and the Agency determined that nearly all of 
those deaths could be prevented by the use of GFCIs or an assured 
grounding program (41 FR 55701). OSHA fatality investigation data 
indicate that only 46 deaths involving 120-volt ground-faults in 
temporary wiring occurred over the years 1990 to 1996 (the latest 
year for which data are complete). This is a death rate of only 6.6 
per year. Thus, OSHA believes that the rule has saved between 24 and 
39 lives per year or, over the 25 years the rule has been in effect, 
a total of between 600 and 975 lives.
---------------------------------------------------------------------------

    The Agency is not proposing to permit the NFPA 70E assured 
grounding program as an alternative to GFCIs in general industry and 
maritime employment. NFPA 70E's assured grounding program differs in 
several important respects from the assured grounding program in OSHA's 
construction standards. For example, NFPA 70E permits the assured 
grounding program as an alternative to GFCIs only (1) for industrial 
establishments with conditions of maintenance and supervision that 
ensure that only qualified personnel are involved and (2) for 
receptacle outlets rated other than 125 volts and 15, 20, or 30 
amperes. The OSHA construction rule recognizes the assured grounding

[[Page 17794]]

program as an alternative to GFCIs without restriction. Additionally, 
under the assured grounding program, NFPA 70E requires electric 
equipment to be tested only when there is evidence of damage. This is 
in contrast to the assured grounding program required by OSHA's 
construction standard, which requires electric equipment to be tested 
after any incident that can reasonably be suspected to have caused 
damage. OSHA believes that these differences would be confusing for 
employers who are subject to both standards and would offer less 
protection for employees.
    OSHA also considered including the assured grounding program 
requirements from the construction standard as an alternative to GFCIs 
in this proposed rule. However, the Agency believes that GFCIs alone, 
without the assured grounding program as an alternative will provide 
better protection for employees. The construction standard's assured 
grounding program demands constant vigilance on the part of employees 
to provide them with the same level of protection as GFCIs. Under that 
program, employers must test cord- and plug-connected equipment 
generally at 3-month intervals, and employees must inspect them daily. 
In contrast, GFCIs constantly monitor the circuit for ground faults and 
open the circuit when ground-fault current becomes excessive without 
the need for either the employer or the employee to take. Considering 
that three fourths of all electrical accidents are caused by poor work 
practices (55 FR 31986), OSHA believes that GFCIs are a much more 
reliable method of protecting employees.
    For these reasons, OSHA believes that this proposal would afford 
better protection for employees than NFPA 70E. However, OSHA requests 
comments on whether the assured grounding program required by the 
electrical standards for construction in Sec.  1926.404(b)(1)(iii) 
provides equal or better protection for employees than GFCIs, and 
whether it should be added as an alternative to GFCIs in the general 
industry electrical installation standard.

E. Carnivals, Circuses, Fairs, and Similar Events

    The proposed standard has new requirements for carnivals, circuses, 
exhibitions, fairs, traveling attractions, and similar events. These 
requirements, which are based on corresponding requirements in NFPA 
70E, would cover the installation of portable wiring and equipment for 
these temporary attractions. From 1991 to 2002, OSHA received reports 
of 46 serious accidents \16\ associated with carnivals, circuses, 
exhibitions, fairs, and similar events. Eleven of these accidents, 
resulting in 10 fatalities and 5 injuries, involved electric shock. 
Eight of those 11 cases (8 fatalities and 1 injury) involved electric 
wiring and equipment covered by the installation requirements in 
Subpart S. OSHA believes that the new electrical requirements for these 
events will prevent similar accidents in the future.
---------------------------------------------------------------------------

    \16\ These accidents were investigated by OSHA generally in 
response to employer reports of a fatality or three or more 
hospitalized injuries.
---------------------------------------------------------------------------

    In paragraph (k) of Sec.  1910.306, mechanical protection of 
electric equipment and wiring methods would be required in and around 
rides, concessions, or other units subject to physical damage. Inside 
tents and concession stands, the electrical wiring for temporary 
lighting would need to be secured and protected from physical damage. 
These new provisions would provide more electrical safety for employees 
working in and around this equipment.
    The disconnecting means would need to be readily accessible to the 
operator; that is, the fused disconnect switch or circuit breaker would 
have to be located within sight and within 6 feet of the operator for 
concession stands and rides. This provision would provide protection by 
enabling the operator to stop the equipment in an emergency. The 
disconnecting means would also have to be lockable if it is exposed to 
unqualified persons, to prevent such persons from operating it.

F. Zone Classification

    Introduction. Section 1910.307 contains OSHA's electrical safety 
requirements for locations that can be hazardous because of the 
presence of flammable or combustible substances. Hazardous locations 
are currently classified according to the properties of flammable 
vapors, liquids or gases, or combustible dusts or fibers that may be 
present. These locations are designated in the NEC and Sec.  1910.307 
as one of six types: Class I, Division 1; Class I, Division 2; Class 
II, Division 1; Class II, Division 2; Class III, Division 1; and Class 
III, Division 2. This system is called the ``division classification 
system,'' or the ``division system.'' The NEC first addressed this 
system in 1920. The OSHA website has a short but informative paper on 
this topic, which is available at http://www.osha.gov/doc/outreachtraining/htmlfiles/hazloc.html.
    The latest version of NFPA 70E incorporates an alternative system 
(in addition to the division classification system) for installing 
electric equipment in Class I locations. (Class II locations continue 
under the division system.) This system is called the ``zone 
classification system,'' or the ``zone system.'' The zone system 
designates three classifications: Class I, Zone 0; Class I, Zone 1; and 
Class I, Zone 2. The zone system is based on various European standards 
that were developed by the International Electrotechnical Commission 
(IEC).\17\ A modified version of this system was first adopted into the 
NEC in the 1996 edition. Although the zone and division classification 
systems differ in concept, individual equipment can be approved for use 
under both systems when the equipment incorporates protective 
techniques for both systems (as determined by the nationally recognized 
testing laboratory that lists or labels the equipment).
---------------------------------------------------------------------------

    \17\ The IEC prepares and publishes international standards for 
all electrical, electronic and related technologies. This global 
organization is made up of members from more than 60 participating 
countries, including the U.S.
---------------------------------------------------------------------------

    The zone system is an alternative method to the division system; 
employers may use either system for installations of electric equipment 
in Class I hazardous locations. OSHA proposes to permit the use of the 
zone system under Sec.  1910.307 and any other OSHA standard that 
references Sec.  1910.307.
    As noted earlier, OSHA is proposing in Sec.  1910.307(b) to require 
employers to document the designation of hazardous locations within 
their facilities. The documentation must denote the boundaries of each 
division or zone so that employees who install, inspect, maintain, or 
operate equipment in these areas will be able to determine whether the 
equipment is safe for the location. As noted earlier, OSHA is proposing 
to require documentation for the division system only for new 
installations that use that system. It would apply to all installations 
made under the zone system.
    Proposed changes to OSHA's existing requirements for the division 
classification system. The term ``hazardous concentrations'' is 
currently used in various definitions of specific hazardous locations 
in Sec.  1910.399. For example, Sec.  1910.399 defines ``Class I, 
Division 1,'' in part, as follows:

    A Class I, Division 1 location is a location: (a) in which 
hazardous concentrations of flammable gases or vapors may exist 
under normal operating conditions * * *

    The proposal would change the term ``hazardous concentrations'' to 
``ignitable concentrations'' in each of the

[[Page 17795]]

definitions. This change would reflect changes already incorporated 
into the 1999 NEC and the 2000 edition of NFPA 70E to make the 
definition more specific about the hazard being addressed. The changes 
will make these definitions clearer in addition to making the OSHA 
standard consistent with the latest editions of NEC and NFPA 70E.
    OSHA is also proposing to add a new paragraph (f) to Sec.  1910.307 
that sets acceptable protection techniques under the division system. 
These requirements address design features that must be used to protect 
employees who are using equipment in a hazardous location classified 
under the division system. Neither the current Subpart S nor NFPA 70E 
explicitly require specific protection techniques that may be used in 
the division classification system; however, the NEC does require 
specific protection techniques for installations made under the 
division classification system in various requirements spread 
throughout the Articles covering hazardous locations. OSHA has listed 
these techniques in one paragraph in the proposal to make the standard 
easier to use and to provide parallel requirements for both the 
division classification system and the zone classification system. 
Protective techniques other than those listed in paragraph (f) are 
acceptable if the equipment is: (1) Intrinsically safe as specified in 
Sec.  1910.307(c)(1); approved for the specific hazardous location as 
specified in Sec.  1910.307(c)(2); or (3) of a type and design that the 
employer demonstrates is safe for the specific hazardous location as 
specified in Sec.  1910.307(c)(3). New paragraph (f) is intended to 
clarify the existing OSHA requirements for hazardous locations by 
explicitly listing the types of protective techniques used under the 
division classification system. (The protection techniques are required 
implicitly under the existing standard through the requirements for 
approval and listing or labeling by a nationally recognized testing 
laboratory and through the reference to the National Electrical Code in 
the note following Sec.  1910.307(b)(3).)
    Brief background and description of the zone system. The zone 
system stemmed from the independent efforts of countries in Europe and 
elsewhere to develop an area classification system to address safety in 
locations containing hazardous substances. The IEC formalized these 
efforts into the zone system, which is now used to classify the 
majority of the world's hazardous location systems.\18\
---------------------------------------------------------------------------

    \18\ Brenon, M., Kelly, P., McManama, K., Klausmeyer, U., Shao, 
W., Smith, P., ``The Impact of the IECEx Scheme on the Global 
Availability of Explosion Protected Apparatus,'' Record of 
Conference Papers of the 1999 Petroleum and Chemical Industry 
Technical Conference, September 13-15, 1999, Paper No. PCIC-99-07, 
pp. 99-109.
---------------------------------------------------------------------------

    Article 505 of the 1996 NEC included requirements for the U.S. 
version of the zone system for the first time. The current version of 
NFPA 70E (NFPA 70E-2000) includes requirements for the zone system 
based on the 1999 version of the NEC. OSHA is proposing to adopt zone 
system rules that are based on these NFPA 70E provisions. This will 
permit electric equipment approved for use in hazardous locations to be 
used in U.S. workplaces, under either the division or zone system.
    Major differences between the division classification system and 
the zone classification system. The zone system can best be described 
by comparing it with the division system. Both systems characterize 
locations by the likelihood and circumstances under which flammable 
gases or vapors exist. The systems both define the types of gases or 
vapors that may exist and categorize them under a number of groups. 
Each system specifies an allowable range of operating temperature, and 
corresponding requirements, for electric equipment used in a particular 
division or zone.
    In contrast to the division system, however, the zone system is 
only used to classify areas that are hazardous because of the presence 
of flammable gases or vapors (Class I locations). The division system 
must be used to classify areas that may contain combustible dusts or 
easily ignitable fibers or flyings (Class II and III locations, 
respectively).
    The zone system defines three types of Class I locations (Zones 0, 
1, and 2) rather than two locations under the division system 
(Divisions 1 and 2). Zones 0 and 1 equate to Division 1, whereas Zone 2 
equates to Division 2. In a Class I, Division 1 location, flammable 
gases or vapors are or may be present in the air in ignitable 
concentrations. In a Class I, Zone 1 location, ignitable concentrations 
of flammable gases or vapors are not always present, but such 
concentrations may exist periodically even under normal conditions. By 
contrast, in a Class I, Zone 0 location, such gases or vapors are 
present either continuously or for long periods of time. (See Table 2.) 
Thus, a Class I, Zone 0 location is, in essence, a worst-case Class I, 
Division 1 location.
    Each system classifies flammable gases and vapors into a number of 
groups. The division system has four such groups, designated A, B, C, 
and D, with group A containing the most volatile substances, and groups 
B, C, and D containing gases or vapors that are progressively less 
volatile. The zone system has three such groups, designated IIA, IIB, 
and IIC, with group IIC containing the most volatile gases, and groups 
IIA and IIB containing gases or vapors that are progressively less 
volatile. Substances classified under Groups A and B in the division 
system generally fall under Group IIC of the zone system. However, some 
differences exist between the groups in the two systems. Thus, 
regardless of the classification system being used, equipment intended 
for use in a Class I hazardous location must indicate the groups for 
which it is approved, as required by proposed Sec.  1910.307(c)(2)(ii) 
and (g)(5)(ii). Table 2 summarizes the similarities and differences 
between the two systems.
    The other major differences concern the allowable protection 
schemes and the maximum allowable surface temperature of equipment 
under each system. The protection schemes acceptable for each division 
and zone are listed in Table 3, and the remainder of this paragraph 
discusses the differences in maximum allowable temperature. According 
to the NEC, equipment is acceptable for a hazardous location only if 
its surface temperatures will not approach the ignition temperature, or 
more specifically the autoignition temperature, of the particular gases 
and vapors that might be present in that location. There are 14 
temperature limits, and corresponding identification codes, under the 
division system. Each limit specifies the maximum surface temperature 
for equipment labeled with the matching code. There are six such 
temperature limits and corresponding identification codes under the 
zone system. The six zone system limits correspond directly to 6 of the 
14 division system temperature limits. However, as shown in Table 2, 
the remaining eight division temperature limits have values 
intermediate to the six zone system temperature limits. For example, 
the division system has 4 intermediate temperature limits, 215[deg]C, 
230[deg]C, 260[deg]C, and 280[deg]C (T2D, T2C, T2B, and T2A, 
respectively), between the zone system's temperature limits of 
200[deg]C (T3) and 300[deg]C (T2). Equipment approved for one of these 
intermediate values may be used under the zone system only for the 
higher (in temperature) of the two closest zone system values. For 
example, equipment marked T2A under the division system, which has a 
maximum surface temperature of 280[deg]C,

[[Page 17796]]

could only be used in locations where the ignition temperature of the 
substance is greater than or equal to the T2 value, which is 300[deg]C. 
In essence, T2A equipment becomes derated to T2 equipment when it is 
installed using the zone classification system. It could not be used in 
zone-classified locations where the ignition temperature of the 
substance is less than or equal to the T3 value, which is 200[deg]C, 
because the equipment could become hot enough to cause ignition.
    More details on the differences in gas groups. In the 1999 NEC, the 
definitions for each of the division system gas and vapor groups, 
except Group A,\19\ were changed to make them comparable to the 
definitions of the zone system groups. A gas or vapor is classified in 
the division system's Group B, C, or D or the zone systems Group IIC, 
IIB, or IIA based on the gas's or vapor's maximum experimental safe gap 
(MESG) \20\ or its minimum igniting current ratio (MIC ratio).\21\ 
These values are established under standard experimental conditions for 
each gas and vapor.
---------------------------------------------------------------------------

    \19\ Acetylene is the only Group A gas under the division 
system.
    \20\ The MESG is the maximum clearance between two parallel 
metal surfaces that has been found, under specified test conditions, 
to prevent an explosion in a test chamber from being propagated to a 
secondary chamber containing the same gas or vapor at the same 
concentration.
    \21\ The MIC ratio is the ratio of the minimum current required 
from an inductive spark discharge to ignite the most easily 
ignitable mixture of a gas or vapor, divided by the minimum current 
required from an inductive spark discharge to ignite methane under 
the same test conditions.
---------------------------------------------------------------------------

    The 1999 NEC indicates two factors that may affect MESG and MIC 
values: (1) Lower ambient temperatures (lower than minus 25[deg]C or 
minus 13[deg]F), and (2) oxygen enriched atmospheres. The 1999 NEC 
Handbook states that the latter factor can drastically change the 
explosion characteristics of materials. Such an atmosphere lowers the 
minimum ignition energy, increases the explosion pressure, and can 
reduce the maximum experimental safe gap. These factors would make it 
unsafe to use otherwise approved ``intrinsically safe'' and 
``explosion-proof'' equipment, unless the equipment has been tested for 
the specific conditions involved. Employers must ensure that the 
equipment approval is valid for the actual conditions present where the 
equipment is installed. This is required generally for all electric 
equipment. However, it is essential in hazardous locations because of 
the dire consequences that may result.
    Rationale for adopting the zone system requirements. As stated 
earlier, the zone system has been accepted in many countries. Such 
international acceptance has meant that U.S. manufacturers of electric 
equipment suitable for installation in hazardous locations have had to 
ensure that their equipment met the zone system requirements if they 
wished to sell such equipment in zone-system countries in addition to 
meeting the U.S. division system requirements. Also, U.S. employers 
that had hazardous locations in their workplaces have sought to use 
equipment approved for use only in zone-classified locations in this 
country. This, in turn, led NFPA to incorporate the zone system in the 
NEC starting in the 1996 edition.
    OSHA has determined that employees can be protected from the 
hazards of explosion in Class I hazardous locations by the installation 
of electric equipment following the latest NEC requirements for the 
zone classification system (Article 505 of the 2002 NEC). Therefore, 
the Agency is incorporating the zone system in this proposed revision 
of the electrical installation requirements in Subpart S. Under the 
proposed standard, employers would be able to comply with either the 
zone classification system or the division system for Class 1 hazardous 
locations.
    New Sec.  1910.307(g) and related definitions. OSHA is proposing to 
add a new paragraph (g) to Sec.  1910.307 to cover the zone 
classification system. This new paragraph addresses the following 
topics: scope; location and general requirements; protection 
techniques; special precaution; and listing and marking. A brief 
description of the contents of each paragraph follows.
    Paragraph (g)(1) permits employers to use the zone classification 
system as an alternative to the division classification system. This 
paragraph also explains that the requirements in Sec.  1910.307 that 
are specific to installations built under the division classification 
do not apply to installations built under the zone classification 
system. Thus, paragraph (c), electrical installations; paragraph (d), 
conduits; paragraph (e), equipment in Division 2 locations; and 
paragraph (f), protection techniques do not apply to installations 
built under the zone system. Paragraph (g) contains counterparts to 
each of these requirements.
    Paragraphs (g)(2)(i) and (ii) describe how hazardous locations are 
classified under the zone system. The employer must consider each 
individual room, section, or area separately and must designate 
locations according to the specific properties of the flammable gases, 
liquids, or vapors that might be present. The same requirements apply 
to the division system. (See Sec.  1910.307(a).)
    Paragraphs (g)(2)(iii) and (g)(2)(iv) require that conduit threads 
be of certain types and that connections be made wrench tight. These 
provisions ensure that there is no arcing across conduit connections in 
the event that they have to carry fault current. Paragraph (d) contains 
similar requirements for division system installations.
    Paragraph (g)(3) presents the protection techniques that are 
acceptable in zone-classified hazardous locations. Electric equipment 
in these locations must incorporate at least one of these protection 
techniques, and the equipment must be approved for the specific 
hazardous location. The protection techniques listed in the proposal 
have been taken directly from NFPA 70E-2000.
    Paragraph (g)(4) sets special precautions that must be taken with 
respect to hazardous locations classified under the zone system. First, 
the classification of areas and the selection of equipment and wiring 
must be under the supervision of a qualified professional engineer. 
This provision is contained in NFPA 70E-2000 and in the 1999 NEC. 
Because the zone system has been permitted in the U.S. only since 
1997,\22\ employers and installers in this country have relatively 
little experience with installations made using the zone classification 
system. The experts that developed NFPA 70E and the NEC have determined 
that, for the zone system, it is essential for competent persons to 
classify the hazardous locations and select equipment for those 
locations. OSHA agrees with these experts. Paragraph (g)(4) also 
indicates when it is safe to have locations classified using the 
division system on the same premises as locations classified under the 
zone system and vice versa. These provisions are also taken from NFPA 
70E-2000.
---------------------------------------------------------------------------

    \22\ As noted earlier, the zone system was first incorporated 
into the NEC in the 1996 edition. This edition was adopted by 
various governmental jurisdictions beginning in 1997. Installations 
made using the zone system were not permitted by these jurisdictions 
before then. In addition, the existing OSHA standard does not permit 
classifying hazardous locations under the zone system, and employers 
have not been certain that installations made using the zone 
classification systems would be acceptable to OSHA.
---------------------------------------------------------------------------

    Paragraph (g)(5) contains requirements for marking equipment that 
is approved for hazardous locations classified under the zone system. 
These provisions are comparable to the corresponding marking 
requirements under the division system, but reflect the need to provide 
information

[[Page 17797]]

necessary for safely installing equipment in a zone-classified 
location.
    Equivalence of systems and permitted protection techniques. Table 2 
shows the general equivalence between the two classification systems. 
It should be noted, however, that a given area classified under one 
system is not permitted to overlap an area classified under the other 
system. For example, although Division 2 and Zone 2 are basically 
equivalent classifications, under the proposed standard a Zone 2 
location is permitted to touch a Division 2 location, but the two 
locations are not permitted to overlap. This ensures that equipment 
installed and maintenance performed in these locations are appropriate 
for the conditions in each location.\23\
---------------------------------------------------------------------------

    \23\ Division 2 and Zone 2 are basically equivalent 
classifications, but there are some differences in what types of 
equipment are acceptable in each of those locations. See, for 
example, the earlier discussion on maximum allowable surface 
temperatures.

 Table 2.--Equivalence of Hazardous (Classified) Location Systems, Class
                          I Locations Only 1 2
------------------------------------------------------------------------
          Category               Division system         Zone system
------------------------------------------------------------------------
Locations...................  Division 1..........  Zone 0, Zone 1.
                              Division 2..........  Zone 2.
Gas Groups (see Table 3       A, B................  IIC (not fully
 since systems are not fully                         equivalent to
 equivalent).                                        Groups A and B).
                              C...................  IIB (not fully
                                                     equivalent to Group
                                                     C).
                              D...................  IIA (not fully
                                                     equivalent to Group
                                                     D).
Temperature Codes...........  T1 (<=450[deg]C)....  T1 (<=450[deg]C).
                              T2 (<=300[deg]C)....  T2 (<=300[deg]C).
                              T2A, T2B, T2C, T2D    T2 (effectively).\3\
                               (<=280, <=260,
                               <=230, <=215[deg]C).
                              T3 (<=200[deg]C)....  T3 (<=200[deg]C).
                              T3A, T3B, T3C         T3 (effectively).\3\
                               (<=180, <=165,
                               <=160[deg]C).
                              T4 (<=135[deg]C)....  T4 (<=135[deg]C).
                              T4A (<=120[deg]C)...  T4 (effectively).\3\
                              T5 (<=100[deg]C)....  T5 (<=100[deg]C).
                              T6 (<=85[deg]C).....  T6 (<=85[deg]C).
------------------------------------------------------------------------
Notes to Table 2:
\1\ Use of the equivalence shown in the table above must be done only as
  permitted by Sec.   1910.307.
\2\ The zone classification system described in this preamble does not
  cover Class II or Class III locations.
\3\ See the discussion of maximum allowable surface temperatures earlier
  in the preamble.

    Table 3 describes which protection techniques may be used in which 
classified locations.

                Table 3.--Permitted Protection Techniques (Design Criteria) in Class I Locations
----------------------------------------------------------------------------------------------------------------
 
                                                                   Zone 0:
                                                                    --intrinsically safe ``ia''
                                                                    --Class I, Division 1 intrinsically safe
Division 1:                                                        Zone 1:
 --explosion-proof                                                  --flameproof ``d''
 --purged and pressurized (Type X or Y)                             --purged and pressurized
 --intrinsically safe                                               --intrinsically safe ``ib''
                                                                    --oil immersion ``o''
                                                                    --increased safety ``e''
                                                                    --encapsulation ``m''
                                                                    --powder filling ``q''
                                                                    --any Class I, Division 1 method
                                                                    --any Class I, Zone 0 method
Division 2:                                                        Zone 2:
 --purged and pressurized (Type Z)                                  --non-sparking ``nA''
 --intrinsically safe                                               --protected sparking ``nC''
 --nonincendive                                                     --restricted breathing ``nR''
 --oil immersion                                                    --any Class I, Division 1 or 2 method
 --hermetically sealed                                              --any Class I, Zone 0 or 1 method
 --any Class I, Division 1 method                                  .............................................
 --any Class I, Zone 0, Zone 1, or Zone 2 method                   .............................................
----------------------------------------------------------------------------------------------------------------

    Listing and labeling by NRTLs. Paragraph (a) of proposed Sec.  
1910.303 would continue the existing requirement that all electric 
equipment be approved. While OSHA believes that approval is necessary 
for all electric equipment, the need for third-party approval of 
electric equipment in hazardous locations is crucial in most 
circumstances. The techniques for ensuring safety in hazardous 
locations require careful manufacturing and testing of products because 
tolerances are tight and the margin for error is slim. Thus, OSHA's 
general industry

[[Page 17798]]

electrical installation standard has always called for equipment 
approval, which generally requires listing or labeling by a nationally 
recognized testing laboratory (NRTL) of equipment installed in 
hazardous locations.\24\ Under 29 CFR 1910.7, OSHA recognizes testing 
organizations that are capable of performing third-party testing for 
safety and designates them as NRTLs. Employers may use products listed 
by NRTLs to meet OSHA standards that require testing and certification. 
NRTLs test and certify equipment to demonstrate conformance to 
appropriate test standards. Many of these test standards cover 
equipment used in hazardous locations.
---------------------------------------------------------------------------

    \24\ Equipment that is of a type that no nationally recognized 
testing laboratory accepts as being safe can achieve approval 
through acceptance by a Federal, State, or local authority having 
jurisdiction over the safety of electrical installations. Custom-
made equipment can gain approval through testing by the equipment 
manufacturer. However, these two modes of approval are rare for 
equipment installed in hazardous locations. Federal, State, and 
local authorities generally look to NRTLs for equipment approval, 
and this is even more true for equipment installed in hazardous 
locations. This type of equipment must be tested to ensure that it 
is safe, and these authorities generally do not have the capability 
to do electrical testing. Custom-made equipment, by its very nature, 
is very rare.
    Existing Sec.  1910.307(b) also recognizes equipment that is 
``safe for the hazardous (classified) location.'' This provision 
permits equipment that is approved for installation in nonhazardous 
locations if the employer demonstrates that the equipment will 
provide protection from the hazards arising from the combustibility 
and flammability of vapors, liquids, gases, dusts, or fibers. This 
condition exists only in limited circumstances as demonstrated by 
the 2002 NEC, which permits only certain types of general-purpose 
equipment in hazardous locations and then only under limited 
conditions. For example, Section 501.8(B) of the 2002 NEC permits 
nonexplosionproof enclosed motors in Class I, Division 2 locations 
if they have no brushes, switching mechanisms, or similar arc-
producing devices and if exposed motor surfaces do not exceed 80 
percent of the ignition temperature of the gas or vapor involved.
---------------------------------------------------------------------------

    OSHA's existing requirements for hazardous locations in Subpart S 
only address locations classified under the division system, and NRTLs 
perform testing based on that system. However, test standards currently 
used by NRTLs to test equipment in hazardous locations classified by 
division are not automatically appropriate for testing such equipment 
for use under the zone system. These current test standards are based 
on protective techniques used for equipment designed for use under the 
division system and do not contain criteria for protective techniques 
used in the zone system. Electric equipment that has been approved by a 
NRTL for use in division-classified hazardous locations may be capable 
of igniting flammable gases or vapors when used inappropriately in 
zone-classified locations. Such hazardous equipment can cause a 
catastrophic explosion and the deaths of and injuries to many 
employees. In recognizing laboratories under Sec.  1910.7 to test 
products designed for installation in zone-classified locations, OSHA 
will ensure that the proper test standards are used and look closely at 
the capability of the laboratory to perform testing under those 
standards.
    Effects and changes to other Part 1910 standards (Sec. Sec.  
1910.103, 1910.106, 1910.107, 1910.110, 1910.178, and 1910.253). A 
number of other OSHA standards under 29 CFR Part 1910 contain 
references to or requirements related to Sec.  1910.307. Some of these 
standards refer only to hazardous locations classified under the 
division system. The standards particularly affected are as follows:
    Sec.  1910.103(b)(3)(ii)(e) and (b)(3)(iii)(e), (c)(1)(ix)(a), and 
(c)(1)(ix)(b);
    Sec.  1910.106(d)(4)(iii), (e)(7)(i)(b), (e)(7)(i)(c), 
(e)(7)(i)(d), (g)(1)(i)(g), (g)(4)(iii)(a), (h)(7)(iii)(b), and 
(h)(7)(iii)(c);
    Sec.  1910.107(c)(6), (c)(8), (j)(4)(iv);
    Sec.  1910.110(b)(17)(v);
    Sec.  1910.178(c)(2)(iv) and (q)(2); and
    Sec.  1910.253(f)(4)(iv)(B) and (f)(6)(v).
    OSHA is not proposing to modify any of these standards in this 
rulemaking. Several of these requirements call for designating 
particular locations as Class I, Division 1 or Division 2 locations, 
and OSHA does not believe that revising them would be a straightforward 
or transparent process. For example, Sec.  1910.103(c)(1)(ix)(a) 
requires electric wiring and equipment ``located within 3 feet of a 
point where connections are regularly made and disconnected, shall be 
in accordance with subpart S of this part, for Class I, Group B, 
Division 1 locations.'' Under the zone system this location would 
likely be partly a Zone 0 location and partly a Zone 1 location. Thus, 
this requirement cannot be revised by a straightforward substitution of 
``Zone'' for ``Division.'' Similar problems exist in revising the other 
requirements. OSHA requests comments on whether these provisions should 
be modified to recognize installations made using the zone system and, 
if so, on what specific changes should be made to accomplish this.

G. Definitions

    The definitions for Subpart S are located in Sec.  1910.399. The 
proposed changes in these definitions reflect the provisions of the 
1999 National Electrical Code and NFPA 70E-2000.
    OSHA is proposing to remove several definitions from the standard. 
``Identified,'' as used in reference to a conductor or its terminal, 
would be removed because the proposal would discontinue the current 
standard's use of the word ``identified'' in this manner. The proposal 
does define ``identified'' to refer to equipment suitable for a 
specific purpose, function, use, environment, or application. ``Special 
permission,'' ``permanently installed swimming pools, wading and 
therapeutic pools,'' and ``storable swimming and wading pools'' would 
be removed because these terms are not used in Subpart S. Lastly, the 
definitions of ``electric sign'' and ``may'' would be removed. The 
existing Subpart S definitions of these terms are not substantially 
different from the commonly accepted dictionary definitions. Thus, 
their removal would not change the meaning of the standard.
    OSHA is proposing to add fifteen definitions to Sec.  1910.399. 
These definitions, all but one of which are based on NFPA 70E-2000, 
will help clarify the requirements in Subpart S. Other modifications 
made to the definitions are grammatical, and no substantive change is 
being made in the meaning of the terms. Table 4 summarizes the changes 
to the definitions.

                                 Table 4.--Summary of Changes to the Definitions
----------------------------------------------------------------------------------------------------------------
              Old definition                             New definition                        Rationale
----------------------------------------------------------------------------------------------------------------
                                            Barrier.................................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
                                            Bathroom................................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
                                            Class I, Zone 0.........................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000 to support the new
                                                                                       section on Zone
                                                                                       Classification in Sec.
                                                                                       1910.307.
                                            Class I, Zone 1.........................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000 to support the new
                                                                                       section on Zone
                                                                                       Classification in Sec.
                                                                                       1910.307.

[[Page 17799]]

 
                                            Class I, Zone 2.........................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000 to support the new
                                                                                       section on Zone
                                                                                       Classification in Sec.
                                                                                       1910.307.
                                            Conductive..............................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
                                            Deenergized.............................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
Electric sign.............................  [Removed]...............................  No substantive change. The
                                                                                       definition adds nothing
                                                                                       to the dictionary
                                                                                       definition of this term.
                                            Energized...............................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
Identified................................  Identified..............................  This term is used in a
                                                                                       different manner in the
                                                                                       proposed revision. The
                                                                                       new use and definition
                                                                                       are taken from NFPA 70E-
                                                                                       2000.
                                            Insulated...............................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
                                            Live parts..............................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
May.......................................  [Removed]...............................  No substantive change. The
                                                                                       definition adds nothing
                                                                                       to the dictionary
                                                                                       definition of this term.
                                            Motor Control Center....................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
                                            Overhaul................................  OSHA would use this term
                                                                                       in the standard in place
                                                                                       of ``major replacement,
                                                                                       modification, repair, or
                                                                                       rehabilitation,'' which
                                                                                       is used in the existing
                                                                                       standard to delineate
                                                                                       when an electrical
                                                                                       installation must meet
                                                                                       new requirements in the
                                                                                       standard. See the
                                                                                       explanation of the
                                                                                       definition and related
                                                                                       changes under the summary
                                                                                       and explanation of the
                                                                                       grandfather clause
                                                                                       earlier in this preamble.
Permanently installed swimming pools,       [Removed]...............................  This term is not used in
 wading and therapeutic pools.                                                         Subpart S.
                                            Service Point...........................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
Special permission........................  [Removed]...............................  This term is not used in
                                                                                       Subpart S.
Storable swimming or wading pool..........  [Removed]...............................  This term is not used in
                                                                                       Subpart S.
                                            Unqualified Person......................  OSHA would add this
                                                                                       definition to Sec.
                                                                                       1910.399 from NFPA 70E-
                                                                                       2000.
Utilization system........................  [Removed]...............................  This definition would be
                                                                                       removed. The existing
                                                                                       definition appears to
                                                                                       conflict with the scope
                                                                                       of Subpart S. See the
                                                                                       detailed explanation
                                                                                       earlier in this section
                                                                                       of the preamble.
----------------------------------------------------------------------------------------------------------------

    A few terms warrant additional explanation: ``identified,'' 
``labeled,'' and ``listed.'' The existing standard requires certain 
electric equipment to be ``approved for the purpose,'' and current 
Sec.  1910.399 defines this term as follows:
    Approved for a specific purpose, environment, or application 
described in a particular standard requirement.
    Suitability of equipment or materials for a specific purpose, 
environment or application may be determined by a nationally 
recognized testing laboratory, inspection agency or other 
organization concerned with product evaluation as part of its 
listing and labeling program. (See ``Labeled'' or ``Listed.'')
    In the proposal, OSHA is replacing the word ``approved,'' when used 
in this sense, with ``identified.'' The proposed definition of 
``identified,'' which is based on the definition of this term in NFPA 
70E,\25\ reads as follows:
---------------------------------------------------------------------------

    \25\ Except for the note to the definition, the exact language 
was taken from the 2002 NEC. This version is clearer than the 
definition in NFPA 70E, but the intent is the same. OSHA has 
clarified the note to indicate that acceptability of testing and 
inspection agencies is given in the definition of ``acceptable.''

    Identified (as applied to equipment). Approved as suitable for 
the specific purpose, function, use, environment, application, and 
---------------------------------------------------------------------------
so forth, where described in a particular requirement.

    Note to the definition of ``identified:'' Some examples of ways 
to determine suitability of equipment for a specific purpose, 
environment, or application include investigations by a nationally 
recognized testing laboratory (through listing and labeling), and 
inspection agency, or other organization recognized under the 
definition of ``acceptable.''

    The proposed definition of ``identified'' as it applies to 
equipment is intended to be equivalent to the existing definition of 
``approved for the purpose.'' \26\
---------------------------------------------------------------------------

    \26\ NFPA 70E uses the word ``recognizable'' in lieu of 
``approved'' in the definition of ``identified.'' It also contains a 
fine print note following the definition indicating that suitability 
of equipment for a specific purpose, environment, or application may 
be determined by a qualified testing laboratory, inspection agency, 
or other organization concerned with product evaluation. The 
proposed and existing OSHA standards both require all electric 
equipment to be approved, and this approval is the only mechanism 
for recognizing equipment as suitable. The Agency believes that the 
proposed definition of ``identified'' as applied to equipment 
clarifies the intent of the standard and is consistent with the 
existing standard's provisions that require electric equipment to be 
``approved for the purpose.''
---------------------------------------------------------------------------

    In the proposal, OSHA uses the terms ``listed'' and ``labeled'' to 
refer to electric equipment determined to be safe by a nationally 
recognized testing laboratory (NRTL). When equipment has been listed 
and labeled, this means that the equipment has been tested and found 
safe for use by a nationally recognized testing laboratory. The 
laboratories mark the equipment with a symbol identifying their 
trademark. The equipment is then considered by OSHA to be safe for its 
intended use. If the equipment is altered or used for other purposes, 
then the equipment is not acceptable under Subpart S. The laboratories 
typically require the equipment to be marked with such information as: 
the standards under which the equipment has been tested; the current 
rating in amperes; and the frequency. OSHA evaluates and recognizes 
``nationally recognized testing laboratories'' under Sec.  1910.7 to 
test equipment for safety and label or list it. It should be noted that 
the proposed rule would continue the existing Sec.  1910.399 
definitions of ``labeled'' and ``listed'' without substantive change.

H. Appendices

    Appendices B and C of current Subpart S contain no material; they 
are reserved for future use. OSHA is proposing to remove these 
``empty'' appendices because neither the Agency nor NFPA 70E currently 
have material to include there. NFPA 70E does have substantial appendix 
material relating to safety-related work practices, but not 
installations, in Part II of that standard. OSHA will consider whether 
to include or use the NFPA 70E appendices when the Agency revises its 
electrical safety-

[[Page 17800]]

related work practices standard (Sec. Sec.  1910.331 through 1910.335) 
in the future.
    Existing Appendix A contains a list of references. OSHA is 
proposing to revise and update the references in this appendix to 
reflect the most recent editions of various national consensus 
standards. These nonmandatory references can assist employers who 
desire additional information that will help them to comply with the 
performance standard in Subpart S. For example, if an employer complies 
with the detailed specifications of the 1999 National Electrical Code, 
the employer will be considered as being in compliance with the more 
performance-oriented requirements found in Subpart S. In addition, OSHA 
is proposing to remove various reference standards from the appendix 
because the documents are no longer in print and because the 
information can be found in other listed sources. The references that 
would be removed are:
    ANSI B9.1-71 Safety Code for Mechanical Refrigeration;
    ANSI B30.7-77 Base Mounted Drum Hoists;
    ANSI B30.15-73 Safety Code for Mobile Hydraulic Cranes;
    ANSI C33.27-74 Safety Standard for Outlet Boxes Fittings for Use in 
Hazardous Locations, Class I, Groups A, B, C, and D, and Class II, 
Groups E, F, and G;
    ASTM D2155-66 Test Method for Autoignition Temperature of Liquid 
Petroleum Products;
    IEEE 463-77 Standard for Electrical Safety Practices in 
Electrolytic Cell Line Working Zones;
    NFPA 56A-73 Standard for the Use of Inhalation Anesthetics 
(Flammable Nonflammable);
    NFPA 56F-74 Standard for Nonflammable Medical Gas Systems;
    NFPA 70C-74 Hazardous Locations Classification;
    NFPA 71-77 Standard for the Installation, Maintenance, and Use of 
Central Station Signaling Systems;
    NFPA 72A-75 Standard for the Installation, Maintenance, and Use of 
Local Protective Signaling Systems for Watchman, Fire Alarm, and 
Supervisory Service;
    NFPA 72B-75 Standard for the Installation, Maintenance, and Use of 
Auxiliary Protective Signaling Systems for Fire Alarms Service;
    NFPA 72C-75 Standards for Installation, Maintenance, and Use of 
Remote Station Protective Signaling Systems;
    NFPA 72D-75 Standard for the Installation, Maintenance and Use of 
Proprietary Protective Signaling Systems for Watchman, Fire Alarm, and 
Supervisory Service;
    NFPA 72E-74 Standard for Automatic Fire Detectors;
    NFPA 74-75 Standard for Installation, Maintenance, and Use of 
Household Fire Warning Equipment;
    NFPA 76A-73 Standard for Essential Electrical Systems for Health 
Care Facilities;
    NFPA 86A-73 Standard for Ovens and Furnaces; Design, Location and 
Equipment;
    NFPA 88B-73 Standard for Repair Garages;
    NFPA 325M-69 Fire-Hazard Properties of Flammable Liquids, Gases, 
and Volatile Solids; and
    NFPA 493-75 Standard for Intrinsically Safe Apparatus for Use in 
Class I Hazardous Locations and Its Associated Apparatus.
    OSHA is proposing to add five national consensus standards to the 
list. All of these documents refer to hazardous (classified) locations.
    ANSI/UL 913-2002 Intrinsically Safe Apparatus and Associated 
Apparatus for Use in Class I, II, and III, Division 1, Hazardous 
(Classified) Locations;
    ANSI/UL 2279-1997 Electrical Equipment for Use in Class I, Zone 0, 
1 and 2 Hazardous (Classified) Locations;
    ANSI/API RP 500-1998 (2002) Recommended Practice for Classification 
of Locations for Electrical Installations at Petroleum Facilities 
Classified as Class I Division 1 and Division 2;
    ANSI/API RP 505-1998 (2002) Recommended Practice for Classification 
of Locations for Electrical Installations at Petroleum Facilities 
Classified as Class I, Zone 0, Zone 1 and Zone 2; and
    NFPA 820-1999 Standard for Fire Protection in Wastewater Treatment 
and Collection Facilities.

I. Powered Platforms for Building Maintenance

    Mandatory Appendix D to Sec.  1910.66, powered platforms for 
building maintenance, applies to powered platforms installed between 
August 28, 1971, and July 23, 1990. Paragraphs (c)(22)(i) and 
(c)(22)(vii) in that appendix incorporate the 1971 National Electrical 
Code by reference. OSHA is proposing to reference Subpart S instead. 
The proposal, which would replace the highly specification-oriented NEC 
with the performance-oriented Subpart S, would make the standard more 
flexible for employers maintaining these platforms but would retain the 
protection currently afforded employees.\27\ In addition, employers 
would no longer need to refer to the NEC to determine how to comply 
with OSHA's standard for powered platforms. The Agency requests 
comments on whether replacing the reference to the NEC with one to 
Subpart S is reasonable and appropriate.
---------------------------------------------------------------------------

    \27\ Employers who make minor modifications to these platforms 
would thus be required to follow Subpart S rather than the 1971 NEC. 
Newer installations and major modifications of older platforms are 
already required to meet Subpart S with respect to the platform's 
electrical wiring and equipment.
---------------------------------------------------------------------------

VI. Preliminary Economic and Regulatory Screening Analysis

A. Existing Versus Proposed Standard

    The proposed rule would revise and update the provisions contained 
in Sections 1910.302-1910.308 and 1910.399 of the existing Subpart S 
electrical installation standard. The original version of Subpart S, 
adopted under section 6(a) of the OSH Act, incorporated the 1971 
National Electrical Code (NEC) by reference. In 1981, OSHA replaced the 
incorporation by reference with updated provisions based on the 1979 
National Fire Protection Association (NFPA) 70E committee 
recommendations. The 1981 version relied on the 1978 NEC. The proposed 
rulemaking will revise and update the OSHA electrical installation 
standard to be consistent with most of the NFPA 70E recommendations 
developed in 2000, which are based on the 1999 NEC, and to update 
requirements for new electrical installations.
    OSHA has conducted a detailed comparison of the existing and 
proposed rules in order to determine which provisions are expected to 
increase compliance costs. Table 5 summarizes the changes associated 
with the provisions of the proposed rule and their implications for 
compliance costs. The OSHA comparative analysis indicates that the 
changes in the proposed rule fall into four categories: (1) Changes in 
hardware specifications that are consistent with NEC requirements; (2) 
changes in installation practices that are consistent with current, 
normal and customary installation practices routinely followed by 
licensed electricians; (3) clarifications of existing requirements that 
do not add additional obligations and/or allow greater flexibility for 
achieving compliance; and (4) requirements that may require significant 
changes in electrical system and equipment installation practices.
    The first three categories of changes introduced by the proposed 
standard are

[[Page 17801]]

not expected to result in any additional costs. Category 1 changes are 
not expected to increase costs because most equipment manufacturers 
routinely follow current NEC requirements regarding hardware 
specifications. Category 2 changes are not expected to result in any 
increase in compliance costs since most licensed electricians routinely 
follow NEC requirements for installing electrical systems and 
equipment. Category 3 changes do not add any new installation or work 
practice requirements, but simply restate or eliminate existing 
requirements.
    Regarding Category 4, a number of changes indicated by the proposed 
rule correspond to revisions to the NEC made prior to 1999. Because 
these changes have been in the NEC since 1996,\28\ they are believed to 
represent widespread current industry practice. Therefore, the changes 
are not expected to result in increased compliance costs. Moreover, 
construction requirements usually imposed by mortgage lenders and 
insurance carriers, as well as installation practices routinely 
followed by licensed electricians (given their formal training), are 
generally consistent with the NEC requirements. In sum, there is a 
subset of Category 4 changes that can be assumed to be equivalent to 
the Category 2 changes described above. Only those Category 4 changes 
that represent additions or revisions to the 1999 NEC are expected to 
potentially result in any increase in compliance costs.
---------------------------------------------------------------------------

    \28\ The 1996 version of the NEC preceded the 1999 version.
---------------------------------------------------------------------------

    As noted, many Category 4 changes are not expected to increase 
compliance costs. In order to avoid having employers incur the costs of 
retrofitting the existing electrical systems and equipment in their 
buildings and facilities, OSHA has identified (in Sec.  1910.302(b)(4)) 
the substantive new provisions in the proposed standard, and then 
excluded (grandfathered) all existing electrical systems and equipment 
installations from having to comply with these new requirements. These 
provisions will only apply to new installations (that is, electrical 
systems and equipment installed for the first time, as well as 
installations that represent a major replacement, modification, repair, 
or rehabilitation of an existing electrical system) made after the 
effective date of the standard. Of the new provisions identified in 
Sec.  1910.302(b)(4), there are 14 provisions (or sets of related 
provisions) in Category 4 that were added or last revised in the 1999 
NEC. A number of these provisions represent changes in design and/or 
operating practices. OSHA believes that with the appropriate lead time 
(that is, sufficient delay in the effective date of the proposed 
standard), these provisions should not result in any incremental costs 
because these requirements can be reviewed and considered, and the 
electrical installation practices altered as necessary, prior to any 
work being performed.
    In addition to the provisions identified in Sec.  1910.302(b)(4), 
there are also new provisions identified in Sec.  1910.302(b)(2) and 
(b)(3) of the proposed standard that apply to: (1) Electrical system 
and equipment installations (either first time or major replacement, 
modification, repair, or rehabilitation) made after March 15, 1972; and 
(2) electrical system and equipment installations (either first time or 
major replacement, modification, repair, or rehabilitation) made after 
April 16, 1981, respectively. Reviewing the provisions identified in 
Sec.  1910.302(b)(2) and (b)(3) of the proposed rule, there are 12 new 
provisions (or sets of related provisions) in Category 4 that were 
added or last revised in the 1999 NEC. Table 5 lists the provisions 
with cost implications. Again, a number of these provisions represent 
changes in design or operating practice rather than new equipment 
requirements, and as discussed earlier, are not expected to result in 
any incremental costs as long as there is sufficient delay in the 
effective date of the proposed standard.
    OSHA has examined other new provisions for possible cost impacts. 
First, Sec.  1910.302(b)(1) of the existing and proposed standards 
identifies those provisions (that is, specific sections in the 
standards) that all new and existing electrical system and equipment 
installations must meet regardless of the installation date. For these 
provisions in the existing and proposed standards, there is no 
grandfathering of older, existing electrical system and equipment 
installations. However, OSHA has concluded that proposed Sec.  
1910.302(b)(1) imposes no new, substantive Category 4 requirements for 
existing electrical systems and equipment installations. Further, while 
Sec.  1910.302(b)(1) does add new coverage from Sec.  1910.307, only 
documentation of hazardous locations is a totally new requirement. The 
rest of the new provisions in Sec.  1910.307 allow employers to 
continue using the division system or to implement an alternative zone 
system for classifying hazardous locations containing flammable gases 
or vapors. They should not result in any additional costs unless 
employers voluntarily choose to abandon their present division system 
in favor of the alternative zone system. Finally, there are new 
proposed provisions not contained in the existing OSHA electrical 
installation standard that were originally in the 1971 NEC and were 
enforced by OSHA between March 15, 1972, and April 16, 1981. The latest 
version of NFPA 70E reincorporated these provisions. OSHA believes that 
these provisions represent widespread current industry practices, 
because they have been part of every version of the NEC since 1971, 
including the 1999 and 2002 editions, and will not impose any 
additional cost.

B. Potentially Affected Establishments

    The proposed electrical safety standard is based primarily upon the 
2000 NFPA 70E recommendations, which in turn, are based on the 1999 
NEC. Consequently, companies that are installing electrical systems and 
equipment in their facilities in locations where the 1999 (or 2002) NEC 
is currently being followed will not be further impacted by OSHA's 
proposed rulemaking with respect to new installations. Further, given 
that there are no new, substantive Category 4 provisions in the 
proposed standard that are mandatory for all existing electrical system 
and equipment installations (see above discussion), these provisions 
will not result in any economic impact for existing installations, 
until they are replaced, repaired, and/or renovated.
    In order to estimate the number of employers potentially impacted 
by the proposed rulemaking, OSHA has identified the States and 
municipalities that currently mandate the 1999 (or 2002) National 
Electrical Code (NEC), that currently mandate using an earlier NEC, or 
that have no mandated statewide electrical code pertaining to new 
installations.\29\ These states were identified using information 
contained in the Directory of Building Codes and Regulations, by City 
and State (National Conference of States on Building Codes and 
Standards, NCSBCS, 2002). In sum, 34 of the 50 States have already 
passed mandatory minimum building or fire codes specifying that new 
construction (including new electrical installations) must meet or 
exceed the requirements of

[[Page 17802]]

the 1999 (or 2002) National Electrical Code (NEC).\30\ Thus, OSHA 
assumes that employers in the covered industries in all locations in 
these 38 States (except for Baltimore, MD) will be unaffected by OSHA's 
proposed rulemaking with respect to new installations. These States 
(with the particular NEC indicated) are listed below:
---------------------------------------------------------------------------

    \29\ In States with no mandated electrical code pertaining to 
new installations, OSHA's existing standards, which are primarily 
based on the 1971 and 1978 NECs, are the governing regulations. (In 
State Plan States, each State has adopted a standard that Federal 
OSHA has found to be at least as effective as the Federal standard. 
For all practical purposes, this means that OSHA's existing standard 
is the governing standard unless the State has adopted a more 
stringent standard.)
    \30\ Maryland has adopted the 1999 NEC as a Mandatory Minimum 
Code, exempting Baltimore from compliance. Generally when a state 
updates these mandatory minimum requirements, the new requirements 
apply only to new facilities or installations.

Alaska (1999)
Arkansas (1999)
California (1999)
Colorado (1999)
Connecticut (1999)
Delaware (1999)
Florida (1999)
Georgia (1999)
Idaho (2002)
Indiana (1999)
Kentucky (2002)
Maine (1999)
Maryland (1999)
Massachusetts (1999)
Michigan (1999)
Minnesota (1999)
Montana (1999)
Nebraska (2002)
New Hampshire (1999)
New Jersey (1999)
New Mexico (1999)
New York (1999)
North Carolina (1999)
North Dakota (2002)
Ohio (2002)
Oklahoma (1999)
Oregon (1999)
Pennsylvania (1999)
Rhode Island (2002)
South Carolina (1999)
South Dakota (2002)
Tennessee (1999)
Utah (1999)
Vermont (1999)
Washington (1999)
West Virginia (1999)
Wisconsin (1999)
Wyoming (1999)

    Moreover, 16 large cities in other States have also adopted the 
1999 NEC. Therefore, employers in the covered industries in these 
municipalities are also expected to be unaffected by OSHA's proposed 
rulemaking with respect to new installations. These cities are listed 
below:

Austin, Texas
Chicago, Illinois
Dallas, Texas
Des Moines, Iowa
El Paso, Texas
Forth Worth, Texas
Honolulu, Hawaii
Houston, Texas
Jackson, Mississippi
Kansas City, Missouri
Las Vegas, Nevada
Phoenix, Arizona
San Antonio, Texas
St. Louis, Missouri
Tucson, Arizona
Wichita, Kansas

    Further, the State of Alabama has adopted a limited mandatory 
minimum code, which requires that a number of industries follow 1999 
NEC. These industries include hotels, schools, and movie theaters. 
Therefore, in this analysis, these identified industries in Alabama 
have been included with the group of 38 States and 16 large cities 
(described above) that currently follow the 1999 NEC.
    The remaining 12 States (or portions of these States) that would 
likely be affected by OSHA's proposed rulemaking can be separated into 
two subgroups: (1) States or municipal jurisdictions that have adopted 
the 1996 version of the NEC; and (2) States that have not adopted any 
statewide electrical code covering all non-government-owned buildings 
or facilities (that is, private sector installations). For group 1, it 
is likely that these jurisdictions will adopt a later version of the 
NEC at some point in the future. This will likely result in lower 
annual compliance costs than estimated below.
    Five States and three cities fall into the first of the two 
subgroups described above. These include all locations in Louisiana and 
Virginia, as well as portions of Arizona, Iowa, and Nevada (that is, 
all locations in these three States excluding the four large cities in 
these States that have adopted the 1999 NEC, as indicated in the list 
above). The three large cities in the first subgroup include Baltimore 
MD, Birmingham AL (excluding hotels, schools, and movie theaters), and 
Washington DC. Employers in these locations may be affected to the 
extent that the 1999 NEC, which is the basis for the proposed 
rulemaking, differs from the 1996 NEC.
    Many of the new provisions in the proposed rule, including those in 
Category 4 that have potential cost implications for new electrical 
systems and equipment installations, date back to the 1996 NEC or to an 
NEC prior to 1996. Thus, for these provisions, employers in locations 
now requiring that the 1996 NEC be followed, will not be affected by 
OSHA's proposed rulemaking with respect to new installations.
    Seven States have not yet adopted any statewide electrical code 
that applies to all private sector employers. These States include: 
Alabama (excluding hotels, schools, and movie theaters), Hawaii, 
Illinois, Kansas, Mississippi, Missouri, and Texas. Employers in these 
States are expected to be the most affected (of the three subgroups) by 
OSHA's proposed rulemaking, since no Statewide electrical code is 
currently required. For these seven States, OSHA's existing electrical 
installation standard, which is primarily based on the 1971 and 1978 
NECs, are the governing regulations.\31\ Below the Statewide level, it 
is not clear to what extent local jurisdictions have passed local 
electrical ordinances that exceed the 1971 and 1978 NECs and are 
consistent with the 1999 NEC. While it is likely that some local 
jurisdictions within these states enforce the 1999 (or 2002) NEC, 
OSHA's analysis treats these States as though they are not in 
compliance with either the 1999 or 2002 NEC for purposes of analysis. 
As a consequence, the estimated compliance costs are likely to be 
overstated.
---------------------------------------------------------------------------

    \31\ Note that of these seven States, Hawaii is the only State 
Plan State. Hawaii has adopted the Federal standard.
---------------------------------------------------------------------------

    Using data from the U.S. Department of Commerce's 1997 County 
Business Patterns (CBP) database, OSHA has estimated the total number 
of affected establishments and employment in those establishments for 
the 58 two-digit SICs covered by general industry electrical safety 
installation standard.\32\ In addition, the number of establishments 
and employment that are already subject to the 1999 NEC, the 1996 NEC, 
the 1990 NEC, and no statewide electrical code, are also estimated. For 
those cities (identified above) that are currently following a 
particular electrical code, OSHA has estimated the number of 
establishments and employment in these cities using, as a surrogate, 
the data for the county in which the cities are located.
---------------------------------------------------------------------------

    \32\ These 58 SICs include employers in maritime employment.
---------------------------------------------------------------------------

    The data indicate that there are an estimated 5.6 million 
establishments with 89.8 million employees in the industries covered by 
the general industry electrical safety installation standard. About 
84.7 percent of the establishments, employing about 85.3 percent of the 
workers, are in States or cities that have adopted the 1999 (or 2002) 
NEC. Approximately 6.3 percent of both the establishments and employees 
are in States or cities that have adopted the 1996 NEC. The remaining 
approximately 9.0 percent of the establishments, employing about 8.4 
percent of the workers, are in States

[[Page 17803]]

(excluding certain cities in these States) that have not adopted a 
statewide electrical code applicable to private sector employers. Table 
6 summarizes these findings.

C. Benefits

    Occupational fatalities associated with electrical accidents remain 
a significant and ongoing problem. The proposed standard would benefit 
workers by reducing their exposure to electrical hazards thereby 
reducing both fatal and nonfatal injuries.
    Table 7 presents data from the Survey of Occupational Injuries and 
Illnesses and the Census of Fatal Occupational Injuries on the number 
of work-related injuries and deaths in private industry attributed to 
contact with electrical current for 1992-2002. While the numbers of 
both injuries and deaths appear to have declined, this decline has not 
been consistent throughout the time for which data are available. 
Electrical-related injuries increased between 1992 and 1994, then 
declined for 1995 to 1997. For 1998 and 1999, injuries again increased. 
Note that the percentage of occupational injuries associated with 
electrical hazards has remained essentially constant throughout 1992 to 
2001. The number of deaths associated with contact with electrical 
current declined in 1993, but rose during 1994 and 1995. Deaths dropped 
in 1996, but rose again in 1997 and 1998. As a percentage of total 
occupational fatalities, death due to electrocution appears to have 
remained constant or declined slightly. However, contact with 
electrical current remains a significant source of occupational 
fatality, accounting for 5.2 percent of total occupational fatalities 
in 2002.
    For more than 30 years, electrical hazards have been a target of 
OSHA regulations. The proposed standard will help to further reduce the 
number of deaths and injuries associated with electrical accidents, and 
ensure that a downward trend in these incidents is sustained.
    To determine the extent to which the proposed standard may reduce 
the number of deaths attributable to electrical accidents, OSHA 
examined its accident investigation reports for the States without any 
statewide electrical code.\33\ The most recent and complete reports 
cover 1990-1996, and provide detailed information on the cause of fatal 
electrical accidents. The accident cause can be used to ascertain 
whether the death would have been prevented by compliance with the 
proposed standard. As an initial screen, OSHA reviewed the reports for 
accidents that could have been prevented through the use of a GFCI. 
While OSHA expects that other provisions of the revised standard 
potentially will reduce deaths due to electrical accidents, this 
initial screen focused on GFCI-related accidents since they are 
relatively easy to isolate using a key word search through all reports. 
Thus, the accident report analysis is conservative in the sense that it 
likely understates the number of deaths preventable under the proposed 
revision to Subpart S.
---------------------------------------------------------------------------

    \33\ Some cities within these States have adopted the 1999 (or 
later) NEC, and these cities were excluded when examining the 
accident report data.
---------------------------------------------------------------------------

    OSHA found that there were at least nine deaths in these seven 
States during 1990-1996, or an average of 1.3 per year, that could have 
been prevented with the use of a GFCI. Based on EPA's estimate of a 
value of $6.1 million for a statistical life, the estimated 1.3 lives 
saved per year (that is, between 1 and 2 lives saved per year) under 
the proposed standard would translate to an annual benefit of $6.1 
million to $12.2 million.\34\ As noted above, the monetized benefits 
understate total benefits since they do cover all potentially 
preventable deaths. Moreover, they do not account for any preventable 
nonfatal injuries.
---------------------------------------------------------------------------

    \34\ See EPA's Guidelines for Preparing Economic Analyses, EPA 
240-R-00-003, September 2000. Note that the $6.1 million is in 1999 
dollars. If this figure is updated for inflation using the CPI as 
EPA indicates is appropriate, the estimated 1.3 lives saved per year 
would translate to an annual benefit of $6.6 million to $13.2 
million (in 2002 dollars).
---------------------------------------------------------------------------

    In addition to quantifiable potential benefits, this update to 
OSHA's electrical standards yields important unquantified benefits. The 
revised standard potentially reduces industry confusion and 
inefficiency associated with the current standard, which is out of date 
with today's technology. While OSHA has a long standing policy of 
permitting employers to comply with more current versions of national 
consensus standards to the extent the more current version is as 
protective as the older version, this does not address all the concerns 
with the outdated standard. The older electrical standards may not 
address the hazards associated with newer equipment and machinery, 
leaving employers unsure which requirements presently apply. For 
example, the proposal contains requirements for electric equipment 
installed in hazardous locations classified under the zone 
classification system, which is not addressed in the existing standard. 
(See the summary and explanation of zone classification in section V. 
F. earlier in the preamble.) The proposed update to Subpart S will 
reduce or eliminate these problems.

D. Estimation of Compliance Costs

    OSHA adopted a conservative approach to estimating compliance 
costs, and consequently, the estimates reported below are likely to 
overstate actual compliance costs. In sum, OSHA did not estimate any 
cost savings associated with the proposed standard, even though many 
new, potentially less costly alternative compliance methods are being 
proposed. For example, as noted above, the proposal would permit 
electric equipment in Class I hazardous locations to be installed under 
the zone classification system, which is not addressed in the existing 
standard. Because the hazardous locations provision potentially reduces 
industry confusion and inefficiency associated with the current 
standard, costs savings are likely.
    For all provisions with the exception of Sec.  
1910.304(b)(4)(ii)(A) and (B), cost estimates were developed on a 
project-level basis. This involved obtaining data on the number of 
construction and other major renovation, addition, and alteration 
projects performed annually in States and local jurisdictions that do 
not now mandate the 1999 NEC (or equivalent).\35\ Table 8 summarizes 
the data on the number of projects potentially impacted by the proposed 
rule. In States and local jurisdictions that do not now mandate the 
1999 NEC (or equivalent), the data indicate that there were a total of 
29,306 project starts in 2001, consisting primarily (91 percent) of 
small projects under $3 million. Less than 0.5 percent of the projects 
were large projects over $25 million.
---------------------------------------------------------------------------

    \35\ Data on new and other (major renovation, addition, and 
alteration) construction projects started annually between 1998 and 
2001 are compiled by F.W. Dodge (Schriver, 2002). While construction 
projects serve as the basis for estimating costs, construction is 
not covered by the proposed standard. Rather, it is the particular 
product or output of the construction project that is covered.
---------------------------------------------------------------------------

    For Sec.  1910.304(b)(4)(ii)(A) and (B), compliance costs were 
estimated on an establishment-level rather than project-level basis. As 
Table 6 suggests, it is estimated that approximately 861,400 
establishments are in locations that either are currently following the 
1996 NEC or have not adopted a statewide electrical code applicable to 
private sector employers. These employers potentially are impacted by 
the proposed rule. Costs per provision were computed according to 
establishment size: establishments with fewer than 99 employees, 
establishments with 100-

[[Page 17804]]

499 employees, and establishments with more than 500 employees.
    All potentially impacted projects/establishments would not 
necessarily be affected by each and every provision, and some would not 
be affected at all in any given year. Thus, it was necessary to 
estimate the percentage of projects/establishments affected by each 
provision annually. This percentage, when multiplied by the number of 
potentially impacted projects/establishments yields the number of 
projects/establishments subject to each provision annually without 
considering baseline levels of compliance. Table 9 presents the 
estimated percentage of projects/establishments that actually would be 
affected by each provision annually. These estimates were based on 
experience and technical knowledge of electrical practices. OSHA seeks 
comment on the accuracy of these estimates.
    Baseline levels of compliance associated with each of the new 
provisions also were considered. Baseline levels of compliance were 
estimated for each provision by considering construction requirements 
imposed by mortgage lenders and insurance carriers and installation 
practices routinely followed by licensed electricians (given their 
formal training). These requirements and installation practices are 
generally consistent with the current NEC requirements. Moreover, it is 
expected that these requirements and practices generally become more 
prevalent as the size of the establishment or project increases. Table 
10 presents the estimated percentages for baseline compliance rates. 
These estimates were based on experience and technical knowledge of 
electrical practices. OSHA seeks comment on the accuracy of the 
estimated levels of baseline compliance.
    For each provision, estimates of labor and material costs were 
developed on a project level basis. Labor costs are based on an hourly 
wage rate of $20.44 for an electrician in the construction sector (SICs 
15-17) to perform the work (plus fringe benefits at 37%).\36\ Costs for 
materials, which consist of labels, GFCIs, conduits, connectors, and 
outlets, are based on data in the Maintenance Direct Catalog of Lab 
Supply, Inc. (2001). Equipment costs were annualized assuming the 
useful life of the equipment is two years and an interest rate of 7 
percent. Table 11 summarizes the key data and bases for the cost 
estimates.
---------------------------------------------------------------------------

    \36\ The wage rate data are for 2000, taken from the BLS (2001) 
2000 National Occupational Employment Statistics (OES) Survey. 
Fringe benefit rate data are from BLS (2000) Employer Costs for 
Employee Compensation, March. USDL: 00-186.
---------------------------------------------------------------------------

    Table 12 presents the estimates. The total annual incremental 
compliance costs associated with the new provisions in the proposed 
standard, for new electrical system and equipment installations, are 
estimated to be $9.8 million. The overwhelmingly majority of costs, 
81.9 percent, are associated with Sec.  1910.304(b)(4)(ii)(A) and (B). 
Since these provisions apply to temporary wiring installations, some of 
the costs and exposures to temporary wiring could potentially be 
incurred by construction employers instead of general industry 
employers. This could occur if general industry employers bring in 
construction companies to make changes in their electrical 
installations. Temporary wiring requirements for construction work are 
already covered under Subpart K of Part 1926; and, consequently, this 
analysis likely overestimates the incremental costs associated with the 
proposed revisions to Subpart S.

E. Technological and Economic Feasibility

    As noted previously, the proposed rule incorporates the NFPA 70E 
recommendations developed in 2000, which are based on the 1999 NEC. The 
NFPA 70E Committee has updated the document in accordance with 
revisions to the NEC, which periodically recodifies acceptable 
electrical practices as a national consensus standard. As noted 
earlier, more than 80 percent of establishments covered by the proposed 
rule are located in areas that currently mandate adherence to these 
recommendations or the 1999 or more stringent version of the NEC. 
Moreover, a number of employers comply with the NFPA 70E 
recommendations in the absence of any legal obligation.\37\ Thus, most 
potentially affected parties already are in compliance with the 
proposed rule, which clearly demonstrates that it is both 
technologically and economically feasible.
---------------------------------------------------------------------------

    \37\ As noted previously, construction requirements imposed by 
mortgage lenders and insurance carriers and installation practices 
followed by licensed electricians (given their formal training) are 
reasons to expect that some employers comply NFPA 70E 
recommendations in the absence of any legal obligation.
---------------------------------------------------------------------------

F. Regulatory Flexibility Screening Analysis and Regulatory Flexibility 
Certification

    In order to determine whether a regulatory flexibility analysis is 
required under the Regulatory Flexibility Act, OSHA has evaluated the 
potential economic impacts of this action on small entities. Table 13 
presents the data used in this analysis to determine whether this 
regulation would have a significant impact on a substantial number of 
small entities.
    First, compliance costs were computed on a per establishment basis, 
which required consideration of the number of establishments 
potentially impacted. The analysis of CBP data discussed above 
indicated that approximately 861,400 establishments are in local 
jurisdictions in the 12 States that are either currently requiring 
compliance with the 1996 NEC or have not adopted a statewide electrical 
code applicable to private sector employers. Regarding the 
documentation provisions for new installations in hazardous locations 
(Sec.  1910.307(b) in Table 12), only those industries that handle 
flammable and/or combustible liquids, vapors, gases, dusts, and/or 
fibers will be impacted. OSHA identified these industries by reviewing 
data on Sec.  1910.307 citations issued between October 2000 and 
September 2001 (available on the OSHA Web site at http://www.osha.gov/oshstats/) and IMIS accident data from 1994 to 2001 indicating Sec.  
1910.307 citations (OSHA, 2001). OSHA estimated that approximately 
441,400 establishments with hazardous locations are in local 
jurisdictions in the 12 States that either are currently following the 
1996 NEC or have not adopted a statewide electrical code applicable to 
private sector employers. These are the establishments potentially 
impacted by the hazardous locations provision. The remaining provisions 
potentially affect all 861,400 establishments in the 12 States as noted 
above.
    OSHA assumed for purposes of conducting the regulatory flexibility 
screening analysis, that small firms, on average, will conduct the same 
type and size of projects as larger establishments. This is a 
conservative assumption, since it is more likely that smaller 
establishments will tend to perform small sized, less costly projects. 
Consequently, OSHA applied average cost per establishment in analyzing 
effect on small entities. The average cost per establishment was 
computed by dividing the total costs reported in Table 12 by the number 
of affected establishments reported in Table 6. For Provisions 1 to 5 
and 7, the cost per establishment is $10.44 and for Provision 6, the 
cost per establishment is $1.92. Thus, for industries that handle 
flammable and/or combustible liquids, vapors, gases, dusts, and/or 
fibers, the total cost per establishment is estimated to be $12.36.

[[Page 17805]]

    OSHA guidelines for determining the need for regulatory flexibility 
analysis require determining the regulatory costs as a percentage of 
the revenues and profits of small entities. OSHA derived estimates of 
the profits and revenues using data from U.S. Census and Dun and 
Bradstreet. In defining a small business, OSHA followed Small Business 
Administration (SBA) criteria for each sector. For many of the affected 
industries, the SBA small business criteria are determined directly by 
the number of employees. But, for those industries where the SBA small 
business criteria are not determined by the number of employees (but 
rather by annual sales), the sales-based criteria were converted to 
employment-based criteria. Specifically, an employment-based firm size 
standard was determined by first calculating an employment level, based 
on the industry average annual receipts per employee, which would be 
sufficient to produce a total sales amount per firm consistent with the 
SBA sales-based firm size standard.
    As shown in Table 13, at worst, compliance costs represent 0.01 
percent of the revenues (for SIC 72, Personal Services) and 0.15 
percent of profits (for SIC 56, apparel and Accessory Stores). On 
average (computed by weighting by number of establishments), compliance 
costs constitute 0.002 percent of revenues and 0.048 percent of 
profits. Based on this evaluation, OSHA certifies that this proposed 
regulation will not have a significant economic impact on a substantial 
number of small entities.\38\
---------------------------------------------------------------------------

    \38\ 38 OSHA also examined the situation where all compliance 
costs accrue to the construction sector (in SIC 1731, Electrical 
Services). In this case, costs constitute 0.04 percent of revenues 
and 1.3 percent of profits. Thus, even if all costs are assigned to 
construction, the proposed regulation will not have a significant 
impact on small entities.

                                         Table 5.--Proposed Changes to Existing Standard With Cost Implications
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Types of                                              Provisions identified in
         Proposed standard            Comments on cost impact      establishments/        Basis for estimating costs      proposed Sec.   1910.302(b)(4)
                                                                  projects affected                                                    \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
1910.303(c)(2)(ii)................  Requires the purchase and   All Establishments     Projects.                         ...............................
                                     installation of labels.     All Projects.
1910.303(h)(5)(iii)(B)............  Requires the purchase and   All Establishments     Projects.                         ...............................
                                     installation of signs.      All Projects.
1910.304(b)(1)....................  Requires the purchase and   All Establishments     Projects........................  X
                                     installation of labels      All Projects.
                                     and identification of
                                     branch circuits.
1910.304(b)(3)....................  Requires the purchase and   All Establishments     Projects........................  X
                                     installation of labels      All Projects.
                                     and identification of
                                     branch circuits.
1910.304(b)(4)(i).................  Requires the purchase and   All Establishments     Projects.                         ...............................
                                     installation of GFCI in     All Projects.
                                     place of standard outlets.
1910.304(b)(4)(ii) (A-B)..........  Requires that facility      All Establishments     Establishments.                   ...............................
                                     purchase GFCI equipment     All Projects.
                                     (power stations or
                                     extension cords) for use
                                     by maintenance personnel.
1910.306(j)(1)(iii)...............  Change in design impacts    Real Estate            Projects........................  X
                                     construction cost (near     Development and
                                     universal compliance        Dwelling Projects.
                                     assumed).
1910.307(b).......................  Facility owner must         Industrial             Projects........................  X
                                     develop documentation.      Establishments All
                                                                 Projects.
1910.308(a)(5)(vi)(B).............  Requires the purchase and   All Establishments     Projects........................  X
                                     installation of labels      All Projects.
                                     and identification.
1910.308(d)(2)(ii)................  Requires the purchase and   All Establishments     Projects.                         ...............................
                                     installation of labels      All Projects.
                                     and identification.
1910.308(e)(1)(i),                  Change in facility design   All Establishments     Projects.                         ...............................
 1910.308(e)(1)(ii),                 and additional materials    Large Projects.
 1910.308(e)(1)(iii).                and installation cost.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Note: Provisions listed in Sec.   1910.302(b)(4) only apply to new installations.


                        Table 6.--Establishments and Employment by Version of NEC Adopted
----------------------------------------------------------------------------------------------------------------
                                                                   Establishments              Employment
                                                             ---------------------------------------------------
                  Applicable version of NEC                      Number     Percent of     Number     Percent of
                                                               (million)      total      (million)      total
----------------------------------------------------------------------------------------------------------------
1996........................................................          0.4          6.3          5.6          6.3
1999 or 2002................................................          4.8         84.7         76.6         85.3
None........................................................          0.5          9.0          7.6          8.4
                                                             --------------
    Total...................................................          5.6          100         89.8         100
----------------------------------------------------------------------------------------------------------------
Source: Compiled from 1997 County Business Patterns database.


[[Page 17806]]


        Table 7.--Fatal and Nonfatal Occupational Injuries Attributable to Contact With Electric Current
----------------------------------------------------------------------------------------------------------------
                                                             Number of    Percent of
                                                              injuries       total                   Percent of
                           Year                              involving     nonfatal     Number of    total fatal
                                                             days away   occupational     deaths    occupational
                                                             from work     injuries                   injuries
----------------------------------------------------------------------------------------------------------------
1992......................................................        4,806           0.2          317           5.8
1993......................................................        4,995           0.2          303           5.4
1994......................................................        6,018           0.3          332           5.6
1995......................................................        4,744           0.2          327           6.0
1996......................................................        4,126           0.2          268           4.8
1997......................................................        3,170           0.2          282           5.0
1998......................................................        3,910           0.2          324           5.9
1999......................................................        4,224           0.2          259           4.7
2000......................................................        3,704           0.2          256           4.8
2001......................................................        3,394           0.2          285           4.8
2002......................................................          N/A           N/A          289          5.2
----------------------------------------------------------------------------------------------------------------
N/A=not available.
Source: U.S. Bureau of Labor Statistics, Survey of Occupational Injuries and Illnesses and the Census of Fatal
  Occupational Injuries (http://www.bls.gov/iif/home.htm).


    Table 8.--Construction Project Starts in 2001 for States That Have Adopted the 1996 NEC or Do Not Have a
                                            Statewide Electrical Code
----------------------------------------------------------------------------------------------------------------
                                                                 Size of project (contract value)
                                                             ---------------------------------------
                        Building type                          Less than      $3-25      More than      Total
                                                               $3 million    million    $25 million
                                                                (small)      (medium)      (large)
----------------------------------------------------------------------------------------------------------------
Commercial and Public Buildings.............................        15219         1490           45        16754
Warehouses..................................................         1659          204            8         1871
Health Facilities and Laboratories..........................         1691          245           33         1969
Funeral and Interment Facilities............................           45  ...........  ...........           45
Athletic and Entertainment Facilities.......................           54            9            2           65
Auto, Bus, and Truck Service................................          797           47  ...........          844
Residential Housing.........................................         1491          169            6         1666
Apartments, Hotels and Dormitories..........................         2505          269           24         2798
Tanks.......................................................          309            8  ...........          317
Hydroelectric Power Plants..................................            3  ...........  ...........            3
Natural Gas Plants..........................................            2            2            1            5
Gas, Water, and Sewer Lines.................................         2340           91            1         2432
Manufacturing Facilities....................................          447           84            6          537
                                                             --------------
    Total...................................................        26562         2618          126       29306
----------------------------------------------------------------------------------------------------------------
Source: William R. Schriver (2002), The University of Tennessee, Knoxville, Construction Industry Research and
  Policy Center, based on F.W. Dodge data on construction project starts for 2001.


 Table 9.--Estimated Percentages of Potentially Affected Projects/Establishments Actually Affected by Provision
                                         and Project/Establishment Size
----------------------------------------------------------------------------------------------------------------
                                                                               Project/establishment size (in
                                                       Description of                     percent)
         Provision No.          Proposed standard        requirement      --------------------------------------
                                                                              Small        Medium       Large
----------------------------------------------------------------------------------------------------------------
1.............................  1910.303(c)(2)(ii  Electrical                       50           50          100
                                 ).                 Connections--Terminal
                                                    s.
2.............................  1910.303(h)(5)(ii  Working Space and                50          100          100
                                 i)(B).             Guarding--Posting of
                                                    Warning Signs.
1a............................  1910.304(b)(1)...  Branch Circuits--                50           50          100
                                                    Identification of
                                                    Multiwire Branch
                                                    Circuits.
1b............................  1910.304(b)(3)...  Branch Circuits--                50           50          100
                                                    Ground-Fault Circuit
                                                    Interrupter
                                                    Protection For
                                                    Personnel.
3.............................  1910.304(b)(4)(i)  Temporary Wiring                100          100          100
                                                    Installations.
4.............................  1910.304(b)(4)(ii  Temporary Wiring                 30           80          100
                                 )(A-B).            Installations.
5.............................  1910.306(j)(1)(ii  Swimming Pools,                  20           80          100
                                 i).                Fountains, and
                                                    Similar
                                                    Installations--Recept
                                                    acles.
6.............................  1910.307(b)......  Hazardous (Classified)           60           80          100
                                                    Locations--Documentat
                                                    ion.
1c............................  1910.308(a)(5)(vi  Systems Over 600                 50           50          100
                                 )(B).              Volts, Nominal--
                                                    Interrupting and
                                                    Isolating Devices.
1d............................  1910.308(d)(2)(ii  Fire Alarm Systems--             50           50          100
                                 ).                 Power Sources.

[[Page 17807]]

 
7.............................  1910.308(e)(1)(i-  Communication Systems--           5           60         100
                                 iii).              Protective Devices.
----------------------------------------------------------------------------------------------------------------
Source: OSHA estimates, based on experience and knowledge of electrical practices.


      Table 10.--Estimated Percentages for Baseline Compliance by Provision and Project/Establishment Size
----------------------------------------------------------------------------------------------------------------
                                                                               Project/establishment size (in
                                                       Description of                     percent)
         Provision No.          Proposed standard        requirement      --------------------------------------
                                                                              Small        Medium       Large
----------------------------------------------------------------------------------------------------------------
1.............................  1910.303(c)(2)(ii  Electrical                       25           25           50
                                 ).                 Connections--Terminal
                                                    s.
2.............................  1910.303(h)(5)(ii  Working Space and                25           25           50
                                 i)(B).             Guarding--Posting of
                                                    Warning Signs.
1a............................  1910.304(b)(1)...  Branch Circuits--                25           25           50
                                                    Identification of
                                                    Multiwire Branch
                                                    Circuits.
1b............................  1910.304(b)(3)...  Branch Circuits--                25           25           50
                                                    Ground-Fault Circuit
                                                    Interrupter
                                                    Protection For
                                                    Personnel.
3.............................  1910.304(b)(4)(i)  Temporary Wiring                 50           95           95
                                                    Installations.
4.............................  1910.304(b)(4)(ii  Temporary Wiring                 50           95           95
                                 )(A-B).            Installations.
5.............................  1910.306(j)(1)(ii  Swimming Pools,                  60           90           90
                                 i).                Fountains, and
                                                    Similar
                                                    Installations--Recept
                                                    acles.
6.............................  1910.307(b)......  Hazardous (Classified)           50           80           80
                                                    Locations--Documentat
                                                    ion.
1c............................  1910.308(a)(5)(vi  Systems Over 600                 25           25           50
                                 )(B).              Volts, Nominal--
                                                    Interrupting and
                                                    Isolating Devices.
1d............................  1910.308(d)(2)(ii  Fire Alarm Systems--             25           25           50
                                 ).                 Power Sources.
7.............................  1910.308(e)(1)(i-  Communication Systems--          10           30          40
                                 iii).              Protective Devices.
----------------------------------------------------------------------------------------------------------------
Source: OSHA estimates, based on experience and knowledge of electrical practices.


                                   Table 11.--Data and Bases for Cost Analysis
----------------------------------------------------------------------------------------------------------------
     Provision No.            Proposed standard                Labor costs                 Material costs
----------------------------------------------------------------------------------------------------------------
1.....................  1910.303(c)(2)(ii)..........  1 minute of labor to install  Cost of label: $1.
                        1910.304(b)(1)..............   label at $28/hour ($20.44 x
                        1910.308(a)(5)(vi)(B).......   1.37).
                        1910.304(b)(3)..............
                        1910.308(d)(2)(ii)..........
2.....................  1910.303(h)(5)(iii)(B)......  1 minute of labor to install  Cost of label: $1.
                                                       label at $28/hour ($20.44 x
                                                       1.37).
3.....................  1910.304(b)(4)(i)...........  None........................  GFCI: $5.
4.....................  1910.304(b)(4)(ii)(A)and (B)  None........................  GFCI power station or cord:
                                                                                     $55 each, annualized over 2-
                                                                                     year useful life.
5.....................  1910.306(j)(1)(iii).........  3 hours at $28/hour ($20.44   Various conduit, connectors,
                                                       x 1.37).                      outlets: $75.
6.....................  1910.307(b).................  4 hours at $28/hour ($20.44   None.
                                                       x 1.37).
7.....................  1910.308(e)(1)(i),(ii), and   1 minute of labor to install  Cost of label: $1.
                         (iii).                        label at $28/hour ($20.44 x
                                                       1.37).
----------------------------------------------------------------------------------------------------------------
Note: The wage rate data are for 2000, taken from the BLS (2001) 2000 National Occupational Employment
  Statistics (OES) Survey. Fringe benefit rate data are from BLS (2000) Employer Costs for Employee
  Compensation, March. USDL: 00-186.


      Table 12.--Annual Incremental Compliance Costs for Proposed Changes to Subpart S Electrical Standard
----------------------------------------------------------------------------------------------------------------
                                                                 Annual costs for projects/establishments \1\
    Provision No.          Proposed        Description of    ---------------------------------------------------
                           standard          requirement         Total        Small        Medium       Large
----------------------------------------------------------------------------------------------------------------
1....................  1910.303(c)(2)(  Electrical                639,881      365,239      239,991       34,651
                        ii).             Connections--Termin
                                         als.
2....................  1910.303(h)(5)(  Working Space and          66,839       49,141       16,145        1,554
                        iii)(B).         Guarding--Posting
                                         of Warning Signs.
                                                             --------------
1a...................  1910.304(b)(1).  Branch Circuits--                   Included in Provision 1
                                         Identification of
                                         Multiwire Branch
                                         Circuits.
                                                             --------------

[[Page 17808]]

 
1b...................  1910.304(b)(3).  Branch Circuits--                   Included in Provision 1
                                         Ground-Fault
                                         Circuit Interrupter
                                         Protection For
                                         Personnel.
 
4....................  1910.304(b)(4)(  Temporary Wiring        8,057,529    7,686,276      206,832      164,420
                        ii)(A-B).        Installations.
5....................  1910.306(j)(1)(  Swimming Pools,            36,050       31,865        3,422          763
                        iii).            Fountains, and
                                         Similar
                                         Installations-
                                         Receptacles.
6....................  1910.307(b)....  Hazardous                 846,930      756,479       77,816       12,635
                                         (Classified)
                                         Locations--Document
                                         ation.
                                                             --------------
1c...................  1910.308(a)(5)(  Systems Over 600                    Included in Provision 1
                        vi)(B).          Volts, Nominal--
                                         Interrupting and
                                         Isolating Devices.
                                                             --------------
1d...................  1910.308(d)(2)(  Fire Alarm Systems--                Included in Provision 1
                        ii).             Power Sources.
                                                             --------------
7....................  1910.308(e)(1)(  Communication              51,044        8,172       37,593        5,280
                        i-iii).          Systems-Protective
                                         Devices.
                                                             --------------
    Total............  ...............  ....................    9,839,204    9,029,982      588,343     220,879
----------------------------------------------------------------------------------------------------------------
\1\ The total cost per establishment is estimated to be $12.36 for industries that handle flammable and/or
  combustible liquids, vapors, gases, dusts, and/or fibers and $10.44 for all other industries.
Source: OSHA estimates
Notes:
(a) Compliance costs for all provisions except 4 are based on projects. Compliance costs for provision 4 are
  based on establishments (small establishments have 1-99 employees medium establishments have 100-499
  employees, and large establishments have 500+ employees).
(b) Represents the number of projects (or establishments) incurring costs. Factors in both the percentage of
  projects (or establishments) for which each provision would be applicable, as well as voluntary compliance
  with each provision.


                                                         Table 13.--Impacts on Small Businesses
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                               Cost as a
                                                                                                                                    Cost as a   percent
 SIC                    Industry description                   Number of SBA      SBA       Revenue per     Profit     Profit per    percent   of Profit
                                                              establishments    revenues   establishment   rate (%)  establishment      of        (in
                                                                                                                                     revenue    percent)
--------------------------------------------------------------------------------------------------------------------------------------------------------
  700  Agricultural services................................       109,663    $38,501,047      $351,085        6.02      $21,130       0.0030     0.0494
  800  Forestry.............................................         2,400      1,496,747       623,645       10.30       64,235       0.0017     0.0163
  900  Fishing, hunting, and trapping.......................            NA             NA            NA        5.80           NA           NA         NA
 1300  Oil And Gas Extraction...............................        14,787     29,931,841     2,024,200        8.65      175,093       0.0006     0.0071
 1500  General building contractors.........................       195,315    234,203,450     1,199,106        4.00       47,964       0.0009     0.0218
 1600  Heavy construction, except building..................        35,618     68,664,092     1,927,792        4.00       77,112       0.0005     0.0135
 1700  Special trade contractors............................       426,477    270,401,924       634,036        4.00       25,361       0.0016     0.0412
 2000  Food And Kindred Products............................        15,992    104,629,113     6,542,591        3.46      226,600       0.0002     0.0055
 2100  Tobacco Products.....................................            91      1,255,255    13,794,011        4.02      554,130       0.0001     0.0022
 2200  Textile Mill Products................................         4,845     20,377,246     4,205,830        2.77      116,423       0.0003     0.0106
 2300  Apparel And Other Textile Products...................        22,383     38,507,048     1,720,370        2.56       44,010       0.0007     0.0281
 2400  Lumber And Wood Products.............................        35,076     58,343,756     1,663,353        3.90       64,854       0.0007     0.0191
 2500  Furniture And Fixtures...............................        11,217     26,295,821     2,344,283        3.51       82,285       0.0005     0.0150
 2600  Paper And Allied Products............................         4,057     31,334,277     7,723,509        4.50      347,629       0.0002     0.0036
 2700  Printing And Publishing..............................        57,018     85,620,541     1,501,641        3.80       57,055       0.0008     0.0217
 2800  Chemicals And Allied Products........................         8,227     59,010,014     7,172,726        4.49      321,776       0.0002     0.0038
 2900  Petroleum And Coal Products..........................         1,047     13,950,653    13,324,406        2.99      398,317       0.0001     0.0031
 3000  Rubber And Misc. Plastics Products...................        13,043     58,709,872     4,501,255        4.02      181,167       0.0003     0.0068
 3100  Leather And Leather Products.........................         1,675      4,003,751     2,390,299        2.20       52,509       0.0005     0.0235
 3200  Stone, Clay, And Glass Products......................        11,791     34,254,470     2,905,137        4.93      143,127       0.0004     0.0086
 3300  Primary Metal Industries.............................         4,806     36,511,582     7,597,083        4.52      343,213       0.0002     0.0036
 3400  Fabricated Metal Products............................        34,250    113,752,781     3,321,249        4.55      150,988       0.0004     0.0082
 3500  Industrial Machinery And Equipment...................        52,548    127,178,710     2,420,239        4.05       97,917       0.0005     0.0126
 3600  Electronic & Other Electric Equipment................        14,355     69,499,940     4,841,514        5.59      270,705       0.0003     0.0046
 3700  Transportation Equipment.............................        10,653     41,544,504     3,899,794        3.74      145,974       0.0003     0.0085
 3800  Instruments And Related Products.....................        10,190     33,908,725     3,327,647        5.06      168,410       0.0004     0.0073
 3900  Miscellaneous Manufacturing Industries...............        17,837     30,627,905     1,717,100        3.80       65,322       0.0007     0.0189
 4000  Railroad transportation..............................            NA             NA            NA       11.08           NA           NA         NA
 4100  Local and interurban passenger transit...............        16,537      7,690,615       465,055        4.51       20,964       0.0022     0.0498
 4200  Trucking And Warehousing.............................       114,623     79,888,400       696,967        3.91       27,278       0.0018     0.0453
 4400  Water Transportation.................................         8,051     14,075,608     1,748,306        7.48      130,855       0.0007     0.0094
 4500  Transportation by air................................         6,386     15,156,218     2,373,351        3.62       85,925       0.0004     0.0121
 4600  Pipelines, Except Natural Gas........................            39        986,979    25,307,154        6.55    1,657,050       0.0000     0.0007

[[Page 17809]]

 
 4700  Transportation Services..............................        40,529     19,513,397       481,468        3.39       16,327       0.0026     0.0757
 4800  Communications.......................................        17,482     41,125,079     2,352,424        5.58      131,244       0.0004     0.0080
 4900  Electric, Gas, And Sanitary Services.................         8,938     10,824,146     1,211,026       10.37      125,641       0.0010     0.0098
 5000  Wholesale Trade--Durable Goods.......................       258,492    837,107,306     3,238,426        2.54       82,401       0.0004     0.0150
 5100  Wholesale Trade--Nondurable Goods....................       143,751    637,454,650     4,434,436        4.46      197,917       0.0003     0.0062
 5200  Building Materials & Garden Supplies.................        46,450     37,776,200       813,266        2.37       19,289       0.0015     0.0641
 5300  General Merchandise Stores...........................         8,796      3,346,901       380,503        2.70       10,283       0.0027     0.1015
 5400  Food Stores..........................................       123,572    101,566,550       821,922        1.41       11,595       0.0013     0.0900
 5500  Automotive Dealers & Service Stations................       116,015    149,337,410     1,287,225        1.45       18,609       0.0010     0.0664
 5600  Apparel And Accessory Stores.........................        50,308     18,706,435       371,838        1.85        6,867       0.0028     0.1520
 5700  Furniture And Homefurnishings Stores.................        78,842     45,392,798       575,744        2.28       13,142       0.0018     0.0794
 5800  Eating And Drinking Places...........................       355,297    128,561,814       361,843        3.00       10,850       0.0034     0.1139
 5900  Miscellaneous Retail.................................       258,538    119,265,615       461,308        2.49       11,479       0.0027     0.1077
 6000  Depository Institutions..............................        14,378     15,538,559     1,080,718       10.80      116,718       0.0010     0.0089
 6100  Nondepository Institutions...........................        21,262     13,454,697       632,805       15.05       95,230       0.0016     0.0110
 6200  Security And Commodity Brokers.......................        27,262     19,644,662       720,588       13.32       95,949       0.0014     0.0109
 6300  Insurance Carriers...................................         4,967      5,850,805     1,177,935        6.82       80,375       0.0009     0.0130
 6400  Insurance Agents, Brokers, & Service.................       119,907     47,083,678       392,668        6.83       26,800       0.0027     0.0390
 6500  Real Estate..........................................       230,304    142,479,284       618,657       13.31       82,340       0.0017     0.0127
 6700  Holding And Other Investment Offices.................        21,022     35,174,755     1,673,235       24.01      401,733       0.0006     0.0026
 7000  Hotels And Other Lodging Places......................        47,698     24,876,889       521,550        6.96       36,302       0.0020     0.0288
 7200  Personal Services....................................       176,477     36,957,629       209,419        5.86       12,262       0.0050     0.0851
 7300  Business Services....................................       337,126    188,061,601       557,838        4.79       26,703       0.0022     0.0463
 7500  Auto Repair, Services, and Parking...................       167,057     66,003,052       395,093        4.39       17,356       0.0031     0.0712
 7600  Miscellaneous Repair Services........................        63,328     25,861,556       408,375        5.44       22,198       0.0030     0.0557
 7800  Motion Pictures......................................        29,959     13,026,870       434,823        5.14       22,341       0.0024     0.0467
 7900  Amusement & Recreation Services......................        90,742     47,922,810       528,122        4.28       22,604       0.0023     0.0547
 8000  Health Services......................................       413,561    243,370,668       588,476        6.17       36,312       0.0021     0.0340
 8100  Legal Services.......................................       156,877     54,265,197       345,909       17.50       60,534       0.0030     0.0172
 8200  Educational Services.................................        40,592     25,677,552       632,577        8.14       51,502       0.0017     0.0203
 8300  Social Services......................................       117,544     50,553,841       430,084        4.44       19,088       0.0024     0.0547
 8400  Museums, Botanical, Zoological Gardens...............         4,912      2,928,264       596,145       21.45      127,873       0.0018     0.0082
 8600  Membership Organizations.............................       242,081     78,452,141       324,074        7.21       23,371       0.0032     0.0447
 8700  Engineering and management services..................       271,169    151,671,072       559,323        6.39       35,745       0.0019     0.0292
 8900  Services, n.e.c......................................        16,395      8,169,059       498,265        6.80       33,882       0.0021     0.0308
--------------------------------------------------------------------------------------------------------------------------------------------------------

VII. State Plan Standards

    The 26 States or territories with OSHA-approved occupational safety 
and health plans must adopt an equivalent amendment or one that is at 
least as protective to employees within 6 months of the publication 
date of the final standard. These are: Alaska, Arizona, California, 
Connecticut (for State and local government employees only), Hawaii, 
Indiana, Iowa, Kentucky, Maryland, Michigan, Minnesota, Nevada, New 
Mexico, New Jersey (for State and local government employees only), New 
York (for State and local government employees only), North Carolina, 
Oregon, Puerto Rico, South Carolina, Tennessee, Utah, Vermont, 
Virginia, Virgin Islands, Washington, and Wyoming.

VIII. Environmental Impact Analysis

    The proposed standard's provisions have been reviewed in accordance 
with the requirements of the National Environmental Policy Act (NEPA) 
of 1969 (42 U.S.C. 4321, et seq.), the regulations of the Council on 
Environmental Quality (40 CFR Part 1502), and the Department of Labor's 
NEPA procedures (29 CFR Part 11). As a result of this review, OSHA has 
determined that these provisions will have no significant effect on 
air, water or soil quality, plant or animal life, on the use of land, 
or other aspects of the environment.

IX. Unfunded Mandates

    This proposed rule has been reviewed in accordance with the 
Unfunded Mandates Reform Act of 1995 (UMRA) (2 U.S.C. 1501 et seq.). 
For the purposes of the UMRA, the Agency certifies that this proposed 
rule does not impose any Federal mandate that may result in increased 
expenditures by State, local, or tribal governments, or increased 
expenditures by the private sector, of more than $100 million in any 
year.

X. Federalism

    OSHA has reviewed this proposed rule in accordance with the 
Executive Order on Federalism (Executive Order 13132, 64 FR 43255, 
August 10, 1999), which requires that agencies, to the extent possible, 
refrain from limiting State policy options, consult with States prior 
to taking any actions that would restrict State policy options, and 
take such actions only when there is clear constitutional authority and 
the presence of a problem of national scope. The Order provides for 
preemption of State law only if there is a clear Congressional intent 
for the Agency to do so. Any such preemption is to be limited to the 
extent possible.
    Section 18 of the OSH Act expresses Congress's intent to preempt 
State laws where OSHA has promulgated occupational safety and health 
standards. A State can avoid preemption on issues covered by Federal 
standards only if it submits, and obtains Federal approval of, a plan 
for the development of such standards and their enforcement. 29 U.S.C. 
667, Gade v. National Solid Wastes Management Association, 505 U.S. 88 
(1992). Occupational safety and health standards developed by such Plan 
States must, among other things, be at least as

[[Page 17810]]

effective in providing safe and healthful employment and places of 
employment as the Federal standards. Subject to the statutory 
limitations of the OSH Act, State-Plan States are free to develop and 
enforce their own requirements for occupational safety and health 
protections related to electrical installation.
    Although OSHA has a clear statutory mandate to preempt state 
occupational safety and health laws, the proposed standard would 
introduce few new requirements that are not already mandated by 
applicable State and local law. As discussed above in the Economic 
Analysis, most States and municipalities require compliance with the 
NEC, which is consistent with the proposed rule.

XI. OMB Review Under the Paperwork Reduction Act of 1995

    The proposed Electrical Standard contains collection-of-information 
(paperwork) requirements that are subject to review by the Office of 
Management and Budget (OMB) under the Paperwork Reduction Act of 1995 
(PRA-95), 44 U.S.C. 3501 et seq., and OMB's regulations at 5 CFR part 
1320. The Paperwork Reduction Act defines ``collection of information'' 
as ``the obtaining, causing to be obtained, soliciting, or requiring 
the disclosure to third parties or the public of facts or opinions by 
or for an agency regardless of form or format * * *'' (44 U.S.C. 
3502(3)(A)). OMB is currently reviewing OSHA's request for approval of 
the proposed collections. OSHA solicits comments on the collection-of-
information requirements and the estimated burden hours associated with 
these collections, including comments on the following:
     Whether the proposed information-collection 
requirements are necessary for the proper performance of the Agency's 
functions, including whether the information is useful;
     The accuracy of OSHA's estimate of the burden 
(time and cost) of the information-collection requirements, including 
the validity of the methodology and assumptions used;
     The quality, utility, and clarity of the 
information collected; and
     Ways to minimize the burden on employers who 
must comply, for example, by using automated or other technological 
techniques for collecting and transmitting information.
    The title, description of the need for and proposed use of the 
information, description of the respondents, and frequency of response 
of the information collections are described below with an estimate of 
the annual reporting burden and cost as required by Sec.  
1320.5(a)(1)(iv) and Sec.  1320.8(d)(2).
    Title: Design Safety Standards for Electrical Systems (Sec. Sec.  
1910.302 through 1910.308).
    Description and Proposed use of the collections of information: The 
proposed standard would impose new information collection requirements 
for purposes of the PRA. These collection of information requirements 
in the proposal (Sec. Sec.  1910.303(f)(5)(i), 1910.303(f)(5)(ii), 
1910.304(b)(1), 1910.304(b)(3), 1910.306(c)(6)(i), 1910.306(c)(6)(ii), 
1910.306(k)(4)(iv)(B), 1910.307(b), 1910.308(b)(3)(i), and 
1910.308(b)(3)(ii)) have not been approved by the Office of Budget and 
Management (OMB). These provisions are needed to provide electrical 
safety to employees against the electric shock hazards that might be 
present in the workplace. The marking of electrical equipment with the 
proper ratings, identifying the phase and system of each ungrounded 
conductor, identifying the disconnecting means with a sign for the 
location, or documenting hazardous classified areas are all ways of 
reducing the electrical hazards pose on employees. OSHA will use the 
records developed in response to this standard to determine compliance. 
The employer's failure to generate and disclose the information 
required in this Standard will affect significantly OSHA's effort to 
control and reduce injuries and fatalities related to electrical 
hazards in the workplace.
    Summary of the Collections of Information: The following are new 
collections of information contained in the Design Safety Standards for 
Electrical Systems (Sec. Sec.  1910.302 through 1910.308).

Section 1910.303 Marking Requirements for Series Combination Ratings

    Paragraphs (f)(5)(i) and (ii) of this section require the employer 
to mark in the indicated field the circuit breakers' and fuses' series 
combination ratings of the equipment given by the manufacture. The 
wording shall state ``Caution--Series Combination System Rated ---- 
Amperes. Identified Replacement Component Required.'' The employer has 
to legibly mark in the blank to indicate the rating.

Section 1910.304 Wiring Design and Protection

    Paragraph (b)(1) of this section requires the employer to identify 
the phase and system of each ungrounded conductor of a multiwire branch 
circuit in a building containing more than one nominal voltage system. 
This marking is required to be permanently posted on each panelboard.
    Paragraph (b)(3) requires the employer to identify the phase and 
system of each ungrounded system conductor in a building where there is 
more than one nominal voltage system. The identification is required to 
be permanently posted at each branch circuit panelboard.

Section 1910.306 Specific Purpose Equipment and Installations

    Paragraph (c)(6)(i) requires the employer to identify the 
disconnecting means with the number that corresponds to the driving 
machine number that it controls where there is more than one driving 
machine in the machine room.
    Paragraph (c)(6)(ii) requires the employer to provide the 
disconnecting means with a sign to identify the location of the supply-
side overcurrent protective device.
    Paragraph (k)(4)(iv)(B) requires the employer to mark the systems 
to which single-pole separable connectors used in portable professional 
motion picture and television equipment are connected if the connectors 
are interchangeable for ac or dc use or for different current ratings 
on the same premises.

Section 1910.307 Hazardous (Classified) Locations

    Paragraph (b) requires the employer to properly document all areas 
designated as hazardous (classified) locations. This documentation 
shall be available to those authorized to design, install, inspect, 
maintain, or operate electric equipment at the location.

Section 1910.308 Special Systems

    Paragraph (b)(3)(i) requires the employer to place a sign at the 
service entrance equipment indicating the type and location of on-site 
emergency power sources. A sign is not required for individual unit 
equipment.
    Paragraph (b)(3)(ii) requires a sign at the grounding location that 
identifies all emergency and normal sources connected at the location.
    Respondents: Employers who design, install, or use electrical 
installations and utilization equipment within or on buildings, 
structures, and other premises.
    Frequency of Response: On occasion. Most of the collections of 
information are markings, labels or signs that provide information to 
protect employees against the electric shock hazards that might be 
present in the workplace. The collections of information are completed 
at the time electrical work is being performed.

[[Page 17811]]

    Average Time per Response: Time per response varies from one minute 
for an engineering manager to brief the technician on the type and 
location of on-site emergency power sources to 4 hours for an 
electrical certified electrical engineer to determine and document all 
areas designated as hazardous (classified) location.
    Total Burden Hours: 8,157.
    Estimated Costs (Operating and Maintenance): -0-.
    Interested parties who wish to comment on the paperwork 
requirements in this proposal must send their written comments to the 
OSHA Docket Office, Docket No. S-108C, Occupational Safety and Health, 
Room N-2625, 200 Constitution Avenue, NW., Washington, DC 20210, and to 
the Office of Information and Regulatory Affairs, New Executive Office 
Building, Office of Management and Budget, Room 10235, 725 17th Street, 
NW., Washington, DC 20503, Attn: OSHA Desk Officer (RIN 1218-AB95)) . 
The Agency also encourages commenters to include their comments on 
paperwork requirements with their other comments on the proposed rule 
submitted to OSHA.

XII. Public Participation

    The Agency requests members of the public to submit written 
comments and other information concerning this proposal. These comments 
may include objections to the proposal with or without a hearing 
request, as well as comments that endorse or support the proposed 
amendment set forth in this notice. OSHA welcomes such comments and 
information so that the record of this rulemaking will represent a 
balanced public response on the issues involved. OSHA is particularly 
interested in receiving comments that address provisions of the 
proposed rule that differ from those in existing Subpart S. See the 
sections above titled DATES and ADDRESSES for information on submitting 
these comments and information to the Agency. Submissions received 
within the specified comment period will become part of the record, and 
will be available for public inspection and copying in the OSHA Docket 
Office.
    Under section 6(b)(3) of the OSH Act and 29 CFR 1911.11, members of 
the public may request an informal hearing by following the 
instructions under the section of this Federal Register notice titled 
ADDRESSES. These requests must include the objections to the proposal 
that warrant a hearing. The party making objections that are part of a 
hearing request must:

     Include their name and address;
     Ensure that the request is sent or postmarked no 
later than June 4, 2004;
     Number each objection separately;
     Specify with particularity the grounds for each 
objection;
     Include a detailed summary of the evidence 
supporting each objection which they plan to offer at the requested 
hearing.

XIII. List of Subjects

    Electric power, Fire prevention, Hazardous substances, Occupational 
safety and health, Safety.

XIV. Authority and Signature

    This document was prepared under the direction of John Henshaw, 
Assistant Secretary of Labor for Occupational Safety and Health, 200 
Constitution Avenue, NW., Washington, DC 20210.
    This action is taken pursuant to sections 4, 6, and 8 of the 
Occupational Safety and Health Act of 1970 (29 U.S.C. 653, 655, 657), 
Secretary of Labor's Order No. 5-2002 (67 FR 65008), and 29 CFR Part 
1911.

    Signed at Washington, DC, this 23rd day of March, 2004.
John Henshaw,
Assistant Secretary of Labor.
    It is proposed to amend Part 1910 of Title 29 of the Code of 
Federal Regulations as follows:

Subpart F--[Amended]

    1. The authority citation for Subpart F would be revised to read as 
follows:

    Authority: Secs. 4, 6, and 8 of the Occupational Safety and 
Health Act of 1970 (29 U.S.C. 653, 655, and 657); Secretary of 
Labor's Order No. 12-71 (36 FR 8754), 8-76 (41 FR 25059), 9-83 (48 
FR 35736), 1-90 (55 FR 9033), or 5-2002 (67 FR 65008), as 
applicable; and 29 CFR part 1911.

Appendix D to Sec.  1910.66 [Amended]

    2. Appendix D to Sec.  1910.66 would be amended as follows:
    a. The words ``the National Electrical Code, NFPA 70-1971; ANSI C1-
1971 (Rev. of C1-1968)'' would be revised to read ``subpart S of this 
part'' in paragraph (c)(22)(i).
    b. The words ``Article 610 of the National Electrical Code, NFPA 
70-1971; ANSI C1--1971 (Rev. of C1-1968)'' would be revised to read 
``subpart S of this part'' in paragraph (c)(22)(vii).

Subpart S--[Amended]

    3. The authority citation for Subpart S would be revised to read as 
follows:

    Authority: Secs. 4, 6, 8, Occupational Safety and Health Act of 
1970 (29 U.S.C. 653, 655, 657); Secretary of Labor's Order No. 8-76 
(41 FR 25059), 1-90 (55 FR 9033), or 5-2002 (67 FR 65008), as 
applicable; 29 CFR part 1911.

    4. Sections 1910.302 through 1910.308 would be revised to read as 
follows:

Design Safety Standards for Electrical Systems


Sec.  1910.302  Electric utilization systems.

    Sections 1910.302 through 1910.308 contain design safety standards 
for electric utilization systems.
    (a) Scope--(1) Covered. The provisions of Sec. Sec.  1910.302 
through 1910.308 of this subpart cover electrical installations and 
utilization equipment installed or used within or on buildings, 
structures, and other premises including:
    (i) Yards,
    (ii) Carnivals,
    (iii) Parking and other lots,
    (iv) Mobile homes,
    (v) Recreational vehicles,
    (vi) Industrial substations,
    (vii) Conductors that connect the installations to a supply of 
electricity, and
    (viii) Other outside conductors on the premises.
    (2) Not covered. The provisions of Sec. Sec.  1910.302 through 
1910.308 of this subpart do not cover:
    (i) Installations in ships, watercraft, railway rolling stock, 
aircraft, or automotive vehicles other than mobile homes and 
recreational vehicles.
    (ii) Installations underground in mines.
    (iii) Installations of railways for generation, transformation, 
transmission, or distribution of power used exclusively for operation 
of rolling stock or installations used exclusively for signaling and 
communication purposes.
    (iv) Installations of communication equipment under the exclusive 
control of communication utilities, located outdoors or in building 
spaces used exclusively for such installations.
    (v) Installations under the exclusive control of electric utilities 
for the purpose of communication or metering; or for the generation, 
control, transformation, transmission, and distribution of electric 
energy located in buildings used exclusively by utilities for such 
purposes or located outdoors on property owned or leased by the utility 
or on public highways, streets, roads, etc., or outdoors by established 
rights on private property.
    (b) Extent of application--(1) Requirements applicable to all 
installations. The following requirements apply to all electrical

[[Page 17812]]

installations and utilization equipment, regardless of when they were 
designed or installed:

Sec.   1910.303(b).....................  Examination, installation, and
                                          use of equipment.
Sec.   1910.303(c)(3)..................  Electrical connections--
                                          Splices.
Sec.   1910.303(d).....................  Arcing parts.
Sec.   1910.303(e).....................  Marking.
Sec.   1910.303(f), except (f)(4) and    Disconnecting means and
 (f)(5).                                  circuits.
Sec.   1910.303(g)(2)..................  600 volts or less--Guarding of
                                          live parts.
Sec.   1910.304(f)(1)(i), (f)(1)(iv),    Overcurrent protection--600
 and (f)(1)(v).                           volts, nominal, or less.
Sec.   1910.304(g)(1)(ii), (g)(1)(iii),  Grounding--Systems to be
 (g)(1)(iv), and (g)(1)(v).               grounded.
Sec.   1910.304(g)(3)..................  Grounding--Grounding
                                          connections.
Sec.   1910.304(g)(4)..................  Grounding--Grounding path.
Sec.   1910.304(g)(5)(iv)(A) through     Grounding--Supports,
 (g)(5)(iv)(D), and (g)(5)(vi).           enclosures, and equipment to
                                          be grounded.
Sec.   1910.304(g)(6)..................  Grounding--Nonelectrical
                                          equipment.
Sec.   1910.304(g)(7)(i)...............  Grounding--Methods of grounding
                                          fixed equipment.
Sec.   1910.305(g)(1)..................  Flexible cords and cables--Use
                                          of flexible cords and cables.
Sec.   1910.305(g)(2)(ii) and            Flexible cords and cables--
 (g)(2)(iii).                             Identification, splices, and
                                          terminations.
Sec.   1910.307........................  Hazardous (classified)
                                          locations.
 

    (2) Requirements applicable to installations made after March 15, 
1972. Every electrical installation and all utilization equipment 
installed or overhauled after March 15, 1972, shall comply with the 
provisions of Sec. Sec.  1910.302 through 1910.308, except as noted in 
paragraphs (b)(3) and (b)(4) of this section.
    (3) Requirements applicable only to installations made after April 
16, 1981. The following requirements apply only to electrical 
installations and utilization equipment installed after April 16, 1981:

Sec.   1910.303(h)(4)..................  Over 600 volts, nominal--
                                          Entrance and access to work
                                          space.
Sec.   1910.304(f)(1)(vii) and           Overcurrent protection--600
 (f)(1)(viii).                            volts, nominal, or less.
Sec.   1910.304(g)(8)(i)...............  Grounding--Grounding of systems
                                          and circuits of 1000 volts and
                                          over (high voltage).
Sec.   1910.305(j)(6)(ii)(D)...........  Equipment for general use--
                                          Capacitors.
Sec.   1910.306(c)(9)..................  Elevators, dumbwaiters,
                                          escalators, moving walks,
                                          wheelchair lifts, and stairway
                                          chair lifts--Interconnection
                                          between multicar controllers.
Sec.   1910.306(i).....................  Electrically driven or
                                          controlled irrigation
                                          machines.
Sec.   1910.306(j)(5)..................  Swimming pools, fountains, and
                                          similar installations--
                                          Fountains.
Sec.   1910.308(a)(1)(ii)..............  Systems over 600 volts,
                                          nominal--Aboveground wiring
                                          methods.
Sec.   1910.308(c)(2)..................  Class 1, Class 2, and Class 3
                                          remote control, signaling, and
                                          power-limited circuits--
                                          Marking.
Sec.   1910.308(d).....................  Fire alarm systems.
 

    (4) Requirements applicable only to installations made after the 
effective date of the final rule. The following requirements apply only 
to electrical installations and utilization equipment installed after 
the effective date of the final rule:

Sec.   1910.303(f)(4)..................  Disconnecting means and
                                          circuits--Capable of accepting
                                          a lock.
Sec.   1910.303(f)(5)..................  Disconnecting means and
                                          circuits--Marking for series
                                          combination ratings.
Sec.   1910.303(g)(1)(iv) and            600 Volts, nominal, or less--
 (g)(1)(vii).                             Space about electric
                                          equipment.
Sec.   1910.303(h)(5)(vi)..............  Over 600 volts, nominal--
                                          Working space and guarding.
Sec.   1910.304(b)(1)..................  Branch circuits--Identification
                                          of multiwire branch circuits.
Sec.   1910.304(b)(3)..................  Branch circuits--Identification
                                          of ungrounded conductors.
Sec.   1910.304(b)(4)(i)...............  Branch circuits--Ground-fault
                                          circuit interrupter protection
                                          for personnel.
Sec.   1910.304(f)(2)(i)(A),             Overcurrent protection--Feeders
 (f)(2)(i)(B) (but not the introductory   and branch circuits over 600
 text to Sec.   1910.304(f)(2)(i)), and   volts, nominal.
 (f)(2)(iv)(A).
Sec.   1910.305(a)(3)(v)...............  Wiring methods--Cable trays.
Sec.   1910.305(c)(3)(ii)..............  Switches--Connection of
                                          switches.
Sec.   1910.305(c)(5)..................  Switches--Grounding.
Sec.   1910.306(a)(1)(ii)..............  Electric signs and outline
                                          lighting--Disconnecting means.
Sec.   1910.306(c)(4)..................  Elevators, dumbwaiters,
                                          escalators, moving walks,
                                          wheelchair lifts, and stairway
                                          chair lifts--Operation.
Sec.   1910.306(c)(5)..................  Elevators, dumbwaiters,
                                          escalators, moving walks,
                                          wheelchair lifts, and stairway
                                          chair lifts--Location.
Sec.   1910.306(c)(6)..................  Elevators, dumbwaiters,
                                          escalators, moving walks,
                                          wheelchair lifts, and stairway
                                          chair lifts--Identification
                                          and signs.
Sec.   1910.306(c)(7)..................  Elevators, dumbwaiters,
                                          escalators, moving walks,
                                          wheelchair lifts, and stairway
                                          chair lifts--Single-car and
                                          multicar installations.
Sec.   1910.306(j)(1)(iii).............  Swimming pools, fountains, and
                                          similar installations--
                                          Receptacles.
Sec.   1910.306(k).....................  Carnivals, circuses, fairs, and
                                          similar events.
Sec.   1910.308(a)(5)(v) and             Systems over 600 volts,
 (a)(5)(vi)(B).                           nominal--Interrupting and
                                          isolating devices.
Sec.   1910.308(a)(7)(vi)..............  Systems over 600 volts,
                                          nominal--Tunnel installations.
Sec.   1910.308(b)(3)..................  Emergency power systems--Signs.

[[Page 17813]]

 
Sec.   1910.308(c)(3)..................  Class 1, Class 2, and Class 3
                                          remote control, signaling, and
                                          power-limited circuits--
                                          Separation from conductors of
                                          other circuits.
Sec.   1910.308(f).....................  Solar photovoltaic systems.
 

    (c) Applicability of requirements for disconnecting means. The 
requirement in Sec.  1910.147(c)(2)(iii) that energy isolating devices 
be capable of accepting a lockout device whenever replacement or major 
repair, renovation or modification of a machine or equipment is 
performed, and whenever new machines or equipment are installed after 
January 2, 1990, applies in addition to any requirements in Sec.  
1910.303 through Sec.  1910.308 that disconnecting means be capable of 
being locked in the open position under certain conditions.


Sec.  1910.303  General.

    (a) Approval. The conductors and equipment required or permitted by 
this subpart shall be acceptable only if approved, as defined in Sec.  
1910.399.
    (b) Examination, installation, and use of equipment--(1) 
Examination. Electric equipment shall be free from recognized hazards 
that are likely to cause death or serious physical harm to employees. 
Safety of equipment shall be determined using the following 
considerations:
    (i) Suitability for installation and use in conformity with the 
provisions of this subpart;

    Note to paragraph (b)(1)(i) of this section: Suitability of 
equipment for an identified purpose may be evidenced by listing or 
labeling for that identified purpose.

    (ii) Mechanical strength and durability, including, for parts 
designed to enclose and protect other equipment, the adequacy of the 
protection thus provided;
    (iii) Wire-bending and connection space;
    (iv) Electrical insulation;
    (v) Heating effects under all conditions of use;
    (vi) Arcing effects;
    (vii) Classification by type, size, voltage, current capacity, and 
specific use; and
    (viii) Other factors that contribute to the practical safeguarding 
of persons using or likely to come in contact with the equipment.
    (2) Installation and use. Listed or labeled equipment shall be 
installed and used in accordance with any instructions included in the 
listing or labeling.
    (3) Insulation integrity. Completed wiring installations shall be 
free from short circuits and from grounds other than those required or 
permitted by this subpart.
    (4) Interrupting rating. Equipment intended to interrupt current at 
fault levels shall have an interrupting rating sufficient for the 
nominal circuit voltage and the current that is available at the line 
terminals of the equipment. Equipment intended to interrupt current at 
other than fault levels shall have an interrupting rating at nominal 
circuit voltage sufficient for the current that must be interrupted.
    (5) Circuit impedance and other characteristics. The overcurrent 
protective devices, the total impedance, the component short-circuit 
current ratings, and other characteristics of the circuit to be 
protected shall be selected and coordinated to permit the circuit 
protective devices used to clear a fault to do so without the 
occurrence of extensive damage to the electrical components of the 
circuit. This fault shall be assumed to be either between two or more 
of the circuit conductors, or between any circuit conductor and the 
grounding conductor or enclosing metal raceway.
    (6) Deteriorating agents. Unless identified for use in the 
operating environment, no conductors or equipment shall be located in 
damp or wet locations; where exposed to gases, fumes, vapors, liquids, 
or other agents that have a deteriorating effect on the conductors or 
equipment; or where exposed to excessive temperatures.
    (7) Mechanical execution of work. Electric equipment shall be 
installed in a neat and workmanlike manner.
    (i) Unused openings in boxes, raceways, auxiliary gutters, 
cabinets, equipment cases, or housings shall be effectively closed to 
afford protection substantially equivalent to the wall of the 
equipment.
    (ii) Conductors shall be racked to provide ready and safe access in 
underground and subsurface enclosures that persons enter for 
installation and maintenance.
    (iii) Internal parts of electrical equipment, including busbars, 
wiring terminals, insulators, and other surfaces may not be damaged or 
contaminated by foreign materials such as paint, plaster, cleaners, 
abrasives, or corrosive residues.
    (iv) There shall be no damaged parts that may adversely affect safe 
operation or mechanical strength of the equipment, such as parts that 
are broken, bent, cut, or deteriorated by corrosion, chemical action, 
or overheating.
    (8) Mounting and cooling of equipment. (i) Electric equipment shall 
be firmly secured to the surface on which it is mounted.

    Note to paragraph (b)(8)(i) of this section: Wooden plugs driven 
into holes in masonry, concrete, plaster, or similar materials are 
not considered secure means of fastening electric equipment.

    (ii) Electric equipment that depends on the natural circulation of 
air and convection principles for cooling of exposed surfaces shall be 
installed so that room airflow over such surfaces is not prevented by 
walls or by adjacent installed equipment. For equipment designed for 
floor mounting, clearance between top surfaces and adjacent surfaces 
shall be provided to dissipate rising warm air.
    (iii) Electric equipment provided with ventilating openings shall 
be installed so that walls or other obstructions do not prevent the 
free circulation of air through the equipment.
    (c) Electrical connections--(1) General. Because of different 
characteristics of dissimilar metals:
    (i) Devices such as pressure terminal or pressure splicing 
connectors and soldering lugs shall be identified for the material of 
the conductor and shall be properly installed and used.
    (ii) Conductors of dissimilar metals may not be intermixed in a 
terminal or splicing connector where physical contact occurs between 
dissimilar conductors (such as copper and aluminum, copper and copper-
clad aluminum, or aluminum and copper-clad aluminum) unless the device 
is identified for the purpose and conditions of use.
    (iii) Materials such as solder, fluxes, inhibitors, and compounds, 
where employed, shall be suitable for the use and shall be of a type 
that will not adversely affect the conductors, installation, or 
equipment.
    (2) Terminals. (i) Connection of conductors to terminal parts shall 
ensure a good connection without damaging the conductors and shall be 
made by means of pressure connectors (including set-screw type), solder 
lugs, or splices to flexible leads. However, No. 10 or smaller 
conductors may be connected by means of wire binding screws or studs 
and nuts having upturned lugs or equivalent.
    (ii) Terminals for more than one conductor and terminals used to 
connect aluminum shall be so identified.
    (3) Splices. (i) Conductors shall be spliced or joined with 
splicing devices

[[Page 17814]]

identified for the use or by brazing, welding, or soldering with a 
fusible metal or alloy. Soldered splices shall first be spliced or 
joined to be mechanically and electrically secure without solder and 
then soldered. All splices and joints and the free ends of conductors 
shall be covered with an insulation equivalent to that of the 
conductors or with an insulating device identified for the purpose.
    (ii) Wire connectors or splicing means installed on conductors for 
direct burial shall be listed for such use.
    (d) Arcing parts. Parts of electric equipment that in ordinary 
operation produce arcs, sparks, flames, or molten metal shall be 
enclosed or separated and isolated from all combustible material.
    (e) Marking--(1) Identification of manufacturer and ratings. 
Electric equipment may not be used unless the following markings have 
been placed on the equipment:
    (i) The manufacturer's name, trademark, or other descriptive 
marking by which the organization responsible for the product may be 
identified; and
    (ii) Other markings giving voltage, current, wattage, or other 
ratings as necessary.
    (2) Durability. The marking shall be of sufficient durability to 
withstand the environment involved.
    (f) Disconnecting means and circuits--(1) Motors and appliances. 
Each disconnecting means required by this subpart for motors and 
appliances shall be legibly marked to indicate its purpose, unless 
located and arranged so the purpose is evident.
    (2) Services, feeders, and branch circuits. Each service, feeder, 
and branch circuit, at its disconnecting means or overcurrent device, 
shall be legibly marked to indicate its purpose, unless located and 
arranged so the purpose is evident.
    (3) Durability of markings. The markings required by paragraphs 
(f)(1) and (f)(2) of this section shall be of sufficient durability to 
withstand the environment involved.
    (4) Capable of accepting a lock. Disconnecting means required by 
this subpart shall be capable of being locked in the open position.
    (5) Marking for series combination ratings. (i) Where circuit 
breakers or fuses are applied in compliance with the series combination 
ratings marked on the equipment by the manufacturer, the equipment 
enclosures shall be legibly marked in the field to indicate that the 
equipment has been applied with a series combination rating.
    (ii) The marking required by paragraph (f)(5)(i) of this section 
shall be readily visible and shall state ``Caution--Series Combination 
System Rated -------- Amperes. Identified Replacement Component 
Required.''
    (g) 600 volts, nominal, or less. The following requirements apply 
to electric equipment operating at 600 volts, nominal, or less to 
ground:
    (1) Space about electric equipment. Sufficient access and working 
space shall be provided and maintained about all electric equipment to 
permit ready and safe operation and maintenance of such equipment.
    (i) Working space for equipment likely to require examination, 
adjustment, servicing, or maintenance while energized shall comply with 
the following dimensions, except as required or permitted elsewhere in 
this subpart:
    (A) The depth of the working space in the direction of access to 
live parts may not be less than indicated in Table S-1. Distances shall 
be measured from the live parts if they are exposed or from the 
enclosure front or opening if they are enclosed.
    (B) The width of working space in front of the electric equipment 
shall be the width of the equipment or 762 mm (30 in.), whichever is 
greater. In all cases, the working space shall permit at least a 90-
degree opening of equipment doors or hinged panels.
    (C) The work space shall be clear and extend from the grade, floor 
or platform to the height required by paragraph (g)(1)(vi) of this 
section. However, other equipment associated with the electrical 
installation and located above or below the electric equipment may 
extend not more than 153 mm (6 in.) beyond the front of the electric 
equipment.
    (ii) Working space required by this standard may not be used for 
storage. When normally enclosed live parts are exposed for inspection 
or servicing, the working space, if in a passageway or general open 
space, shall be suitably guarded.
    (iii) At least one entrance of sufficient area shall be provided to 
give access to the working space about electric equipment.
    (iv) For equipment rated 1200 amperes or more and over 1.83 m (6.0 
ft) wide, containing overcurrent devices, switching devices, or control 
devices, there shall be one entrance not less than 610 mm (24 in.) wide 
and 1.98 m (6.5 ft) high at each end of the working space. Where the 
location permits a continuous and unobstructed way of exit travel, one 
means of exit is permitted. Where the working space required by 
paragraph (g)(1)(i) of this section is doubled, only one entrance to 
the working space is required, and the entrance shall be located so 
that the edge of the entrance nearest the equipment is the minimum 
clear distance given in Table S-1 away from such equipment.
    (v) Illumination shall be provided for all working spaces about 
service equipment, switchboards, panelboards, and motor control centers 
installed indoors. Additional lighting fixtures are not required where 
the working space is illuminated by an adjacent light source. In 
electric equipment rooms, the illumination may not be controlled by 
automatic means only.
    (vi) The minimum headroom of working spaces about service 
equipment, switchboards, panelboards, or motor control centers shall be 
as follows:
    (A) For installations built before the effective date of the final 
rule, 1.91 m (6.25 ft); and
    (B) For installations built on or after the effective date of the 
final rule, 1.98 m (6.5 ft), except that where the electrical equipment 
exceeds 1.98 m (6.5 ft) in height, the minimum headroom may not be less 
than the height of the equipment.

              Table S-1.--Minimum Depth of Clear Working Space at Electric Equipment, 600 V or Less
----------------------------------------------------------------------------------------------------------------
                                                            Minimum clear distance for condition 2 3
                                               -----------------------------------------------------------------
           Nominal voltage to ground                 Condition A           Condition B           Condition C
                                               -----------------------------------------------------------------
                                                    m          ft         m          ft         m          ft
----------------------------------------------------------------------------------------------------------------
0--150........................................    \1\ 0.9    \1\ 3.0    \1\ 0.9    \1\ 3.0        0.9        3.0
151--600......................................    \1\ 0.9    \1\ 3.0        1.0        3.5        1.2        4.0
----------------------------------------------------------------------------------------------------------------
Notes to Table S-1:
\1\ Minimum clear distances may be 0.7 m (2.5 ft) for installations built before April 16, 1981.

[[Page 17815]]

 
\2\ Conditions A, B, and C are as follows:
Condition A--Exposed live parts on one side and no live or grounded parts on the other side of the working
  space, or exposed live parts on both sides effectively guarded by suitable wood or other insulating material.
  Insulated wire or insulated busbars operating at not over 300 volts are not considered live parts.
Condition B--Exposed live parts on one side and grounded parts on the other side.
Condition C--Exposed live parts on both sides of the work space (not guarded as provided in Condition A) with
  the operator between.
\3\ Working space is not required in back of assemblies such as dead-front switchboards or motor control centers
  where there are no renewable or adjustable parts (such as fuses or switches) on the back and where all
  connections are accessible from locations other than the back. Where rear access is required to work on
  deenergized parts on the back of enclosed equipment, a minimum working space of 762 mm (30 in.) horizontally
  shall be provided.

    (vii) Switchboards, panelboards, and distribution boards installed 
for the control of light and power circuits, and motor control centers 
shall be located in dedicated spaces and protected from damage.
    (A) For indoor installation, the dedicated space shall comply with 
the following:
    (1) The space equal to the width and depth of the equipment and 
extending from the floor to a height of 1.83 m (6.0 ft) above the 
equipment or to the structural ceiling, whichever is lower, shall be 
dedicated to the electrical installation. Unless isolated from 
equipment by height or physical enclosures or covers that will afford 
adequate mechanical protection from vehicular traffic or accidental 
contact by unauthorized personnel or that complies with paragraph 
(g)(1)(vii)(A)(2) of this section, piping, ducts, or equipment foreign 
to the electrical installation may not be located in this area.
    (2) The space equal to the width and depth of the equipment shall 
be kept clear of foreign systems unless protection is provided to avoid 
damage from condensation, leaks, or breaks in such foreign systems. 
This area shall extend from the top of the electric equipment to the 
structural ceiling.
    (3) Sprinkler protection is permitted for the dedicated space where 
the piping complies with this section.
    (4) Control equipment that by its very nature or because of other 
requirements in this subpart must be adjacent to or within sight of its 
operating machinery is permitted in the dedicated space.

    Note to paragraph (g)(1)(vii)(A) of this section: A dropped, 
suspended, or similar ceiling that does not add strength to the 
building structure is not considered a structural ceiling.

    (B) Outdoor electric equipment shall be installed in suitable 
enclosures and shall be protected from accidental contact by 
unauthorized personnel, or by vehicular traffic, or by accidental 
spillage or leakage from piping systems. No architectural appurtenance 
or other equipment may be located in the working space required by 
paragraph (g)(1)(i) of this section.
    (2) Guarding of live parts. (i) Except as elsewhere required or 
permitted by this standard, live parts of electric equipment operating 
at 50 volts or more shall be guarded against accidental contact by use 
of approved cabinets or other forms of approved enclosures or by any of 
the following means:
    (A) By location in a room, vault, or similar enclosure that is 
accessible only to qualified persons.
    (B) By suitable permanent, substantial partitions or screens so 
arranged so that only qualified persons will have access to the space 
within reach of the live parts. Any openings in such partitions or 
screens shall be so sized and located that persons are not likely to 
come into accidental contact with the live parts or to bring conducting 
objects into contact with them.
    (C) By placement on a suitable balcony, gallery, or platform so 
elevated and otherwise located as to prevent access by unqualified 
persons.
    (D) By elevation of 2.44 m (8.0 ft) or more above the floor or 
other working surface.
    (ii) In locations where electric equipment is likely to be exposed 
to physical damage, enclosures or guards shall be so arranged and of 
such strength as to prevent such damage.
    (iii) Entrances to rooms and other guarded locations containing 
exposed live parts shall be marked with conspicuous warning signs 
forbidding unqualified persons to enter.
    (h) Over 600 volts, nominal--(1) General. Conductors and equipment 
used on circuits exceeding 600 volts, nominal, shall comply with all 
applicable provisions of the paragraphs (a) through (g) of this section 
and with the following provisions, which supplement or modify the 
preceding requirements. However, paragraphs (h)(2), (h)(3), and (h)(4) 
of this section do not apply to the equipment on the supply side of the 
service point.
    (2) Enclosure for electrical installations. (i) Electrical 
installations in a vault, room, or closet or in an area surrounded by a 
wall, screen, or fence, access to which is controlled by lock and key 
or other approved means, are considered to be accessible to qualified 
persons only. The type of enclosure used in a given case shall be 
designed and constructed according to the hazards associated with the 
installation.
    (ii) For installations other than equipment described in paragraph 
(h)(2)(v) of this section, a wall, screen, or fence shall be used to 
enclose an outdoor electrical installation to deter access by persons 
who are not qualified. A fence may not be less than 2.13 m (7.0 ft) in 
height or a combination of 1.80 m (6.0 ft) or more of fence fabric and 
a 305-mm (1-ft) or more extension utilizing three or more strands of 
barbed wire or equivalent.
    (iii) The following requirements apply to indoor installations that 
are accessible to other than qualified persons:
    (A) The installations shall be made with metal-enclosed equipment 
or shall be enclosed in a vault or in an area to which access is 
controlled by a lock.
    (B) Metal-enclosed switchgear, unit substations, transformers, pull 
boxes, connection boxes, and other similar associated equipment shall 
be marked with appropriate caution signs.
    (C) Openings in ventilated dry-type transformers and similar 
openings in other equipment shall be designed so that foreign objects 
inserted through these openings will be deflected from energized parts.
    (iv) Outdoor electrical installations having exposed live parts 
shall be accessible to qualified persons only.
    (v) The following requirements apply to outdoor enclosed equipment 
accessible to unqualified employees:
    (A) Ventilating or similar openings in equipment shall be so 
designed that foreign objects inserted through these openings will be 
deflected from energized parts.
    (B) Where exposed to physical damage from vehicular traffic, 
suitable guards shall be provided.
    (C) Nonmetallic or metal-enclosed equipment located outdoors and 
accessible to the general public shall be designed so that exposed nuts 
or bolts cannot be readily removed, permitting access to live parts.
    (D) Where nonmetallic or metal-enclosed equipment is accessible to 
the general public and the bottom of the enclosure is less than 2.44 m 
(8.0 ft) above the floor or grade level, the enclosure door or hinged 
cover shall be kept locked.

[[Page 17816]]

    (E) Except for underground box covers that weigh over 45.4 kg (100 
lb), doors and covers of enclosures used solely as pull boxes, splice 
boxes, or junction boxes shall be locked, bolted, or screwed on.
    (3) Work space about equipment. Sufficient space shall be provided 
and maintained about electric equipment to permit ready and safe 
operation and maintenance of such equipment. Where energized parts are 
exposed, the minimum clear work space may not be less than 1.98 m (6.5 
ft) high (measured vertically from the floor or platform) or less than 
914 mm (3.0 ft) wide (measured parallel to the equipment). The depth 
shall be as required in paragraph (h)(5)(i) of this section. In all 
cases, the work space shall be adequate to permit at least a 90-degree 
opening of doors or hinged panels.
    (4) Entrance and access to work space. (i) At least one entrance 
not less than 610 mm (24 in.) wide and 1.98 m (6.5 ft) high shall be 
provided to give access to the working space about electric equipment.
    (A) On switchboard and control panels exceeding 1.83 m (6.0 ft) in 
width, there shall be one entrance at each end of such boards unless 
the location of the switchboards and control panels permits a 
continuous and unobstructed way of exit travel, or unless the work 
space required in paragraph (h)(5)(i) of this section is doubled.
    (B) Where one entrance to the working space is permitted under the 
conditions described in paragraph (h)(4)(i)(A) of this section, the 
entrance shall be located so that the edge of the entrance nearest the 
switchboards and control panels is the minimum clear distance given in 
Table S-2 away from such equipment.
    (C) Where bare energized parts at any voltage or insulated 
energized parts above 600 volts, nominal, to ground are located 
adjacent to such entrance, they shall be suitably guarded.
    (ii) Permanent ladders or stairways shall be provided to give safe 
access to the working space around electric equipment installed on 
platforms, balconies, mezzanine floors, or in attic or roof rooms or 
spaces.
    (5) Working space and guarding. (i) Except as elsewhere required or 
permitted in this subpart, the minimum clear working space in the 
direction of access to live parts of electric equipment may not be less 
than specified in Table S-2. Distances shall be measured from the live 
parts, if they are exposed, or from the enclosure front or opening, if 
they are enclosed.
    (ii) If switches, cutouts, or other equipment operating at 600 
volts, nominal, or less, are installed in a room or enclosure where 
there are exposed live parts or exposed wiring operating at over 600 
volts, nominal, the high-voltage equipment shall be effectively 
separated from the space occupied by the low-voltage equipment by a 
suitable partition, fence, or screen. However, switches or other 
equipment operating at 600 volts, nominal, or less, and serving only 
equipment within the high-voltage vault, room, or enclosure may be 
installed in the high-voltage enclosure, room, or vault if accessible 
to qualified persons only.
    (iii) The following requirements apply to the entrances to all 
buildings, rooms, or enclosures containing exposed live parts or 
exposed conductors operating at over 600 volts, nominal:
    (A) The entrances shall be kept locked unless they are under the 
observation of a qualified person at all times.
    (B) Permanent and conspicuous warning signs shall be provided, 
reading substantially as follows:
    ``DANGER--HIGH VOLTAGE--KEEP OUT.''
    (iv) Illumination shall be provided for all working spaces about 
electric equipment.
    (A) The lighting outlets shall be arranged so that persons changing 
lamps or making repairs on the lighting system will not be endangered 
by live parts or other equipment.
    (B) The points of control shall be located so that persons are 
prevented from contacting any live part or moving part of the equipment 
while turning on the lights.
    (v) Unguarded live parts above working space shall be maintained at 
elevations not less than specified in Table S-3.
    (vi) Pipes or ducts that are foreign to the electrical installation 
and that require periodic maintenance or whose malfunction would 
endanger the operation of the electrical system may not be located in 
the vicinity of service equipment, metal-enclosed power switchgear, or 
industrial control assemblies. Protection shall be provided where 
necessary to avoid damage from condensation leaks and breaks in such 
foreign systems.

    Note to paragraph (h)(5)(vi) of this section: Piping and other 
facilities are not considered foreign if provided for fire 
protection of the electrical installation.


               Table S-2.--Minimum Depth of Clear Working Space at Electric Equipment, Over 600 V
----------------------------------------------------------------------------------------------------------------
                                                            Minimum clear distance for condition 2 3
                                               -----------------------------------------------------------------
           Nominal voltage to ground                 Condition A           Condition B           Condition C
                                               -----------------------------------------------------------------
                                                    m          ft         m          ft         m          Ft
----------------------------------------------------------------------------------------------------------------
601-2500 V....................................        0.9        3.0        1.2        4.0        1.5        5.0
2501-9000 V...................................        1.2        4.0        1.5        5.0        1.8        6.0
9001 V-25 kV..................................        1.5        5.0        1.8        6.0        2.8        9.0
Over 25-75 kV \1\.............................        1.8        6.0        2.5        8.0        3.0       10.0
Above 75 kV \1\...............................        2.5        8.0        3.0       10.0        3.7      12.0
----------------------------------------------------------------------------------------------------------------
Notes to Table S-2:
\1\ Minimum depth of clear working space in front of electric equipment with a nominal voltage to ground above
  25,000 volts may be the same as that for 25,000 volts under Conditions A, B, and C for installations built
  before April 16, 1981.
\2\ Conditions A, B, and C are as follows:
Condition A--Exposed live parts on one side and no live or grounded parts on the other side of the working
  space, or exposed live parts on both sides effectively guarded by suitable wood or other insulating material.
  Insulated wire or insulated busbars operating at not over 300 volts are not considered live parts.
Condition B--Exposed live parts on one side and grounded parts on the other side. Concrete, brick, and tile
  walls are considered as grounded surfaces.
Condition C--Exposed live parts on both sides of the work space (not guarded as provided in Condition A) with
  the operator between.
\3\ Working space is not required in back of equipment such as dead-front switchboards or control assemblies
  that has no renewable or adjustable parts (such as fuses or switches) on the back and where all connections
  are accessible from locations other than the back. Where rear access is required to work on the deenergized
  parts on the back of enclosed equipment, a minimum working space 762 mm (30 in.) horizontally shall be
  provided.


[[Page 17817]]


    Table S-3.--Elevation of Unguarded Live Parts Above Working Space
------------------------------------------------------------------------
                                               Elevation
   Nominal voltage between   -------------------------------------------
           phases                       m                    ft
------------------------------------------------------------------------
601-7500 V..................  2.8 \1\.............  9.0 \1\
7501 V-35 kV................  2.8.................  9.0
Over 35 kV..................  2.8 + 9.5 mm/kV over  9.0 + 0.37 in./kV
                               35 kV.                over 35 kV
------------------------------------------------------------------------
\1\ The minimum elevation may be 2.6 m (8.5 ft) for installations built
  before the effective date of the standard.

Sec.  1910.304  Wiring design and protection.

    (a) Use and identification of grounded and grounding conductors--
(1) Identification of conductors. (i) A conductor used as a grounded 
conductor shall be identifiable and distinguishable from all other 
conductors.
    (ii) A conductor used as an equipment grounding conductor shall be 
identifiable and distinguishable from all other conductors.
    (2) Polarity of connections. No grounded conductor may be attached 
to any terminal or lead so as to reverse designated polarity.
    (3) Use of grounding terminals and devices. A grounding terminal or 
grounding-type device on a receptacle, cord connector, or attachment 
plug may not be used for purposes other than grounding.
    (b) Branch circuits--(1) Identification of multiwire branch 
circuits. Where more than one nominal voltage system exists in a 
building containing multiwire branch circuits, each ungrounded 
conductor of a multiwire branch circuit, where accessible, shall be 
identified by phase and system. The means of identification shall be 
permanently posted at each branch-circuit panelboard.
    (2) Receptacles and cord connectors. (i) Receptacles installed on 
15- and 20-ampere branch circuits shall be of the grounding type except 
as permitted for replacement receptacles in paragraph (b)(2)(iv) of 
this section. Grounding-type receptacles shall be installed only on 
circuits of the voltage class and current for which they are rated, 
except as provided in Table S-4 and Table S-5.
    (ii) Receptacles and cord connectors having grounding contacts 
shall have those contacts effectively grounded except for receptacles 
mounted on portable and vehicle-mounted generators in accordance with 
paragraph (g)(2) of this section and replacement receptacles installed 
in accordance with paragraph (b)(2)(iv) of this section.
    (iii) The grounding contacts of receptacles and cord connectors 
shall be grounded by connection to the equipment grounding conductor of 
the circuit supplying the receptacle or cord connector. The branch 
circuit wiring method shall include or provide an equipment grounding 
conductor to which the grounding contacts of the receptacle or cord 
connector shall be connected.
    (iv) Replacement of receptacles shall comply with the following 
requirements:
    (A) Where a grounding means exists in the receptacle enclosure or a 
grounding conductor is installed, grounding-type receptacles shall be 
used and shall be connected to the grounding means or conductor.
    (B) Ground-fault circuit-interrupter protected receptacles shall be 
provided where replacements are made at receptacle outlets that are 
required to be so protected elsewhere in this subpart.
    (C) Where a grounding means does not exist in the receptacle 
enclosure, the installation shall comply with one of the following 
provisions:
    (1) A nongrounding-type receptacle may be replaced with another 
nongrounding-type receptacle; or
    (2) A nongrounding-type receptacle may be replaced with a ground-
fault circuit-interrupter-type of receptacle that is marked ``No 
Equipment Ground;'' an equipment grounding conductor may not be 
connected from the ground-fault circuit-interrupter-type receptacle to 
any outlet supplied from the ground-fault circuit-interrupter 
receptacle; or
    (3) A nongrounding-type receptacle may be replaced with a 
grounding-type receptacle where supplied through a ground-fault 
circuit-interrupter; the replacement receptacle shall be marked ``GFCI 
Protected'' and ``No Equipment Ground;'' an equipment grounding 
conductor may not be connected to such grounding-type receptacles.
    (v) Receptacles connected to circuits having different voltages, 
frequencies, or types of current (ac or dc) on the same premises shall 
be of such design that the attachment plugs used on these circuits are 
not interchangeable.
    (3) Identification of ungrounded conductors. Where more than one 
nominal voltage system exists in a building, each ungrounded system 
conductor shall be identified by phase and system. This means of 
identification shall be permanently posted at each branch-circuit 
panelboard.
    (4) Ground-fault circuit interrupter protection for personnel. (i) 
All 125-volt, single-phase, 15- and 20-ampere receptacles installed in 
bathrooms or on rooftops shall have ground-fault circuit-interrupter 
protection for personnel.
    (ii) The following requirements apply to temporary wiring 
installations that are used during maintenance, remodeling, or repair 
of buildings, structures, or equipment or during similar activities:
    (A) All 125-volt, single-phase, 15- and 20- and 30-ampere 
receptacle outlets that are not part of the permanent wiring of the 
building or structure and that are in use by personnel shall have 
ground-fault circuit-interrupter protection for personnel. However, 
receptacles on a 2-wire, single-phase portable or vehicle-mounted 
generator rated not more than 5 kW, where the circuit conductors of the 
generator are insulated from the generator frame and all other grounded 
surfaces, are permitted without ground-fault circuit-interrupter 
protection for personnel.

    Note 1 to paragraph (b)(4)(ii)(A) of this section: A cord 
connector on an extension cord set is considered to be a receptacle 
outlet if the cord set is used for temporary electric power.


    Note 2 to paragraph (b)(4)(ii)(A) of this section: Cord sets and 
devices incorporating listed ground-fault circuit-interrupter 
protection for personnel are acceptable forms of protection.

    (B) Receptacles other than 125 volt, single-phase, 15-, 20-, and 
30-ampere receptacles that are not part of the permanent wiring of the 
building or structure and that are in use by personnel shall have 
ground-fault circuit-interrupter protection for personnel.
    (5) Outlet devices. Outlet devices shall have an ampere rating not 
less than the load to be served and shall comply with the following 
provisions:
    (i) Where connected to a branch circuit having a rating in excess 
of 20 amperes, lampholders shall be of the heavy-duty type. A heavy-
duty lampholder shall have a rating of not less than 660 watts if of 
the admedium

[[Page 17818]]

type and not less than 750 watts if of any other type.
    (ii) Receptacle outlets shall comply with the following provisions:
    (A) A single receptacle installed on an individual branch circuit 
shall have an ampere rating of not less than that of the branch 
circuit.
    (B) Where connected to a branch circuit supplying two or more 
receptacles or outlets, a receptacle may not supply a total cord- and 
plug-connected load in excess of the maximum specified in Table S-4.
    (C) Where connected to a branch circuit supplying two or more 
receptacles or outlets, receptacle ratings shall conform to the values 
listed in Table S-5; or, where larger than 50 amperes, the receptacle 
rating may not be less than the branch-circuit rating. However, 
receptacles of cord- and plug-connected arc welders may have ampere 
ratings not less than the minimum branch-circuit conductor ampacity.
    (6) Cord connections. A receptacle outlet shall be installed 
wherever flexible cords with attachment plugs are used. Where flexible 
cords are permitted to be permanently connected, receptacles may be 
omitted.

     Table S-4.--Maximum Cord- and Plug-Connected Load to Receptacle
------------------------------------------------------------------------
                                                 Receptacle    Maximum
           Circuit rating (amperes)                rating        load
                                                 (amperes)    (amperes)
------------------------------------------------------------------------
15 or 20......................................           15           12
20............................................           20           16
30............................................           30           24
------------------------------------------------------------------------


        Table S-5.--Receptacle Ratings for Various Size Circuits
------------------------------------------------------------------------
         Circuit rating (amperes)            Receptacle rating (amperes)
------------------------------------------------------------------------
15........................................  Not over 15.
20........................................  15 or 20.
30........................................  30.
40........................................  40 or 50.
50........................................  50.
------------------------------------------------------------------------

    (c) Outside conductors, 600 volts, nominal, or less. The following 
requirements apply to branch-circuit, feeder, and service conductors 
rated 600 volts, nominal, or less and run outdoors as open conductors.
    (1) Conductors on poles. Conductors on poles shall have a 
separation of not less than 305 mm (1.0 ft) where not placed on racks 
or brackets. Conductors supported on poles shall provide a horizontal 
climbing space not less than the following:
    (i) Power conductors below communication conductors--762 mm (30 
in.);
    (ii) Power conductors alone or above communication conductors:
    300 volts or less--610 mm (24 in.),
    Over 300 volts--762 mm (30 in.);
    (iii) Communication conductors below power conductors--same as 
power conductors;
    (iv) Communications conductors alone--no requirement.
    (2) Clearance from ground. Open conductors, open multiconductor 
cables, and service-drop conductors of not over 600 volts, nominal, 
shall conform to the minimum clearances specified in Table S-6.

                                       Table S-6.--Clearances From Ground
----------------------------------------------------------------------------------------------------------------
                               Installations built before the effective    Installations built on or after the
                                        date of the final rule               effective date of the final rule
          Distance           -----------------------------------------------------------------------------------
                                                                            Voltage to
                               Maximum voltage         Conditions             ground             Conditions
----------------------------------------------------------------------------------------------------------------
3.05 m (10.0 ft)............  < 600 V..........  Above finished grade    < 150 V.........  Above finished grade
                                                  or sidewalks, or from                     or sidewalks, or
                                                  any platform or                           from any platform or
                                                  projection from which                     projection from
                                                  they might be                             which they might be
                                                  reached. (If these                        reached. (If these
                                                  areas are accessible                      areas are accessible
                                                  to other than                             to other than
                                                  pedestrian traffic,                       pedestrian traffic,
                                                  then one of the other                     then one of the
                                                  conditions applies.).                     other conditions
                                                                                            applies.)
3.66 m (12.0 ft)............  < 600 V..........  Over areas, other than  < 300 V.........  Over residential
                                                  public streets,                           property and
                                                  alleys, roads, and                        driveways.
                                                  driveways, subject to                    Over commercial areas
                                                  vehicular traffic                         subject to
                                                  other than truck                          pedestrian traffic
                                                  traffic.                                  or to vehicular
                                                                                            traffic other than
                                                                                            truck traffic
                                                                                           (This category
                                                                                            includes conditions
                                                                                            covered under the
                                                                                            3.05-m (10.0-ft)
                                                                                            category where the
                                                                                            voltage exceeds 150
                                                                                            V.)
4.57 m (15.0 ft)............  < 600 V..........  Over areas, other than  301 to 600 V....  Over residential
                                                  public streets,                           property and
                                                  alleys, roads, and                        driveways
                                                  driveways, subject to                    Over commercial areas
                                                  truck traffic.                            subject to
                                                                                            pedestrian traffic
                                                                                            or to vehicular
                                                                                            traffic other than
                                                                                            truck traffic.
                                                                                           (This category
                                                                                            includes conditions
                                                                                            covered under the
                                                                                            3.05-m (10.0-ft)
                                                                                            category where the
                                                                                            voltage exceeds 300
                                                                                            V.)
5.49 m (18.0 ft)............  < 600 V..........  Over public streets,    < 600 V.........  Over public streets,
                                                  alleys, roads, and                        alleys, roads, and
                                                  driveways.                                driveways.
                                                                                           Over commercial areas
                                                                                            subject to truck
                                                                                            traffic.
                                                                                           Other land traversed
                                                                                            by vehicles,
                                                                                            including land used
                                                                                            for cultivating or
                                                                                            grazing and forests
                                                                                            and orchards.
----------------------------------------------------------------------------------------------------------------


[[Page 17819]]

    (3) Clearance from building openings. (i) Service conductors 
installed as open conductors or multiconductor cable without an overall 
outer jacket shall have a clearance of not less than 914 mm (3.0 ft) 
from windows that are designed to be opened, doors, porches, balconies, 
ladders, stairs, fire escapes, and similar locations. However, 
conductors that run above the top level of a window may be less than 
914 mm (3.0 ft) from the window. Vertical clearance of final spans 
above, or within 914 mm (3.0 ft) measured horizontally of, platforms, 
projections, or surfaces from which they might be reached shall be 
maintained in accordance with paragraph (c)(2) of this section.
    (ii) Overhead service conductors may not be installed beneath 
openings through which materials may be moved, such as openings in farm 
and commercial buildings, and may not be installed where they will 
obstruct entrance to these building openings.
    (4) Above roofs. Overhead spans of open conductors and open 
multiconductor cables shall have a vertical clearance of not less than 
2.44 m (8.0 ft) above the roof surface. The vertical clearance above 
the roof level shall be maintained for a distance not less than 914 mm 
(3.0 ft) in all directions from the edge of the roof.
    (i) The area above a roof surface subject to pedestrian or 
vehicular traffic shall have a vertical clearance from the roof surface 
in accordance with the clearance requirements of paragraph (c)(2) of 
this section.
    (ii) A reduction in clearance to 914 mm (3.0 ft) is permitted where 
the voltage between conductors does not exceed 300 and the roof has a 
slope of 102 mm (4 in.) in 305 mm (12 in.) or greater.
    (iii) A reduction in clearance above only the overhanging portion 
of the roof to not less than 457 mm (18 in.) is permitted where the 
voltage between conductors does not exceed 300 if (1) the conductors do 
not pass above the roof overhang for a distance of more than 1.83 m 
(6.0 ft), 1.22 m (4.0 ft) horizontally, and (2) the conductors are 
terminated at a through-the-roof raceway or approved support.
    (iv) The requirement for maintaining a vertical clearance of 914 mm 
(3.0 ft) from the edge of the roof does not apply to the final 
conductor span where the conductors are attached to the side of a 
building.
    (d) Location of outdoor lamps. Lamps for outdoor lighting shall be 
located below all energized conductors, transformers, or other electric 
equipment, unless such equipment is controlled by a disconnecting means 
that can be locked in the open position, or unless adequate clearances 
or other safeguards are provided for relamping operations.
    (e) Services--(1) Disconnecting means. (i) Means shall be provided 
to disconnect all conductors in a building or other structure from the 
service-entrance conductors. The service disconnecting means shall 
plainly indicate whether it is in the open or closed position and shall 
be installed at a readily accessible location nearest the point of 
entrance of the service-entrance conductors.
    (ii) Each service disconnecting means shall simultaneously 
disconnect all ungrounded conductors.
    (iii) Each service disconnecting means shall be suitable for the 
prevailing conditions.
    (2) Services over 600 volts, nominal. The following additional 
requirements apply to services over 600 volts, nominal.
    (i) Service-entrance conductors installed as open wires shall be 
guarded to make them accessible only to qualified persons.
    (ii) Signs warning of high voltage shall be posted where 
unqualified employees might come in contact with live parts.
    (f) Overcurrent protection--(1) 600 volts, nominal, or less. The 
following requirements apply to overcurrent protection of circuits 
rated 600 volts, nominal, or less.
    (i) Conductors and equipment shall be protected from overcurrent in 
accordance with their ability to safely conduct current.
    (ii) Except for motor running overload protection, overcurrent 
devices may not interrupt the continuity of the grounded conductor 
unless all conductors of the circuit are opened simultaneously.
    (iii) A disconnecting means shall be provided on the supply side of 
all fuses in circuits over 150 volts to ground and cartridge fuses in 
circuits of any voltage where accessible to other than qualified 
persons so that each individual circuit containing fuses can be 
independently disconnected from the source of power. However, a 
current-limiting device without a disconnecting means is permitted on 
the supply side of the service disconnecting means. In addition, a 
single disconnecting means is permitted on the supply side of more than 
one set of fuses as permitted by the exception to Sec.  
1910.305(j)(4)(vi), for group operation of motors and for fixed 
electric space-heating equipment.
    (iv) Overcurrent devices shall be readily accessible to each 
employee or authorized building management personnel. These overcurrent 
devices may not be located where they will be exposed to physical 
damage or in the vicinity of easily ignitable material.
    (v) Fuses and circuit breakers shall be so located or shielded that 
employees will not be burned or otherwise injured by their operation. 
Handles or levers of circuit breakers, and similar parts that may move 
suddenly in such a way that persons in the vicinity are likely to be 
injured by being struck by them, shall be guarded or isolated.
    (vi) Circuit breakers shall clearly indicate whether they are in 
the open (off) or closed (on) position.
    (vii) Where circuit breaker handles on switchboards are operated 
vertically rather than horizontally or rotationally, the up position of 
the handle shall be the closed (on) position.
    (viii) Circuit breakers used as switches in 120-volt and 277-volt, 
fluorescent lighting circuits shall be listed and marked ``SWD.''
    (ix) A circuit breaker with a straight voltage rating, such as 240 
V or 480 V, may only be installed in a circuit in which the nominal 
voltage between any two conductors does not exceed the circuit 
breaker's voltage rating. A two-pole circuit breaker may not be used 
for protecting a 3-phase, corner-grounded delta circuit unless the 
circuit breaker is marked 1[phis]-3[phis] to indicate such suitability. 
A circuit breaker with a slash rating, such as 120/240 V or 480Y/277 V, 
may only be installed in a circuit where the nominal voltage of any 
conductor to ground does not exceed the lower of the two values of the 
circuit breaker's voltage rating and the nominal voltage between any 
two conductors does not exceed the higher value of the circuit 
breaker's voltage rating.
    (2) Feeders and branch circuits over 600 volts, nominal. The 
following requirements apply to feeders and branch circuits energized 
at more than 600 volts, nominal:
    (i) Feeder and branch-circuit conductors shall have overcurrent 
protection in each ungrounded conductor located at the point where the 
conductor receives its supply or at a location in the circuit 
determined under engineering supervision.
    (A) Circuit breakers used for overcurrent protection of three-phase 
circuits shall have a minimum of three overcurrent relays operated from 
three current transformers. On three-phase, three-wire circuits, an 
overcurrent relay in the residual circuit of the current transformers 
may replace one of the phase relays. An overcurrent relay, operated 
from a current transformer that links all phases of a three-phase, 
three-wire circuit, may replace the residual relay and one other phase-
conductor

[[Page 17820]]

current transformers. Where the neutral is not grounded on the load 
side of the circuit, the current transformer may link all three phase 
conductors and the grounded circuit conductor (neutral).
    (B) If fuses are used for overcurrent protection, a fuse shall be 
connected in series with each ungrounded conductor.
    (ii) Each protective device shall be capable of detecting and 
interrupting all values of current that can occur at its location in 
excess of its trip setting or melting point.
    (iii) The operating time of the protective device, the available 
short-circuit current, and the conductor used shall be coordinated to 
prevent damaging or dangerous temperatures in conductors or conductor 
insulation under short-circuit conditions.
    (iv) The following additional requirements apply to feeders only:
    (A) The continuous ampere rating of a fuse may not exceed three 
times the ampacity of the conductors. The long-time trip element 
setting of a breaker or the minimum trip setting of an electronically 
actuated fuse may not exceed six times the ampacity of the conductor. 
For fire pumps, conductors may be protected for short circuit only.
    (B) Conductors tapped to a feeder may be protected by the feeder 
overcurrent device where that overcurrent device also protects the tap 
conductor.
    (g) Grounding. Paragraphs (g)(1) through (g)(8) of this section 
contain grounding requirements for systems, circuits, and equipment.
    (1) Systems to be grounded. Systems that supply premises wiring 
shall be grounded as follows:
    (i) All 3-wire dc systems shall have their neutral conductor 
grounded.
    (ii) Two-wire dc systems operating at over 50 volts through 300 
volts between conductors shall be grounded unless:
    (A) They supply only industrial equipment in limited areas and are 
equipped with a ground detector; or
    (B) They are rectifier-derived from an ac system complying with 
paragraphs (g)(1)(iii), (g)(1)(iv), and (g)(1)(v) of this section; or
    (C) They are fire-alarm circuits having a maximum current of 0.030 
amperes.
    (iii) AC circuits of less than 50 volts shall be grounded if they 
are installed as overhead conductors outside of buildings or if they 
are supplied by transformers and the transformer primary supply system 
is ungrounded or exceeds 150 volts to ground.
    (iv) AC systems of 50 volts to 1000 volts shall be grounded under 
any of the following conditions, unless exempted by paragraph (g)(1)(v) 
of this section:
    (A) If the system can be so grounded that the maximum voltage to 
ground on the ungrounded conductors does not exceed 150 volts;
    (B) If the system is nominally rated three-phase, four-wire wye 
connected in which the neutral is used as a circuit conductor;
    (C) If the system is nominally rated three-phase, four-wire delta 
connected in which the midpoint of one phase is used as a circuit 
conductor; or
    (D) If a service conductor is uninsulated.
    (v) AC systems of 50 volts to 1000 volts are not required to be 
grounded under any of the following conditions:
    (A) If the system is used exclusively to supply industrial electric 
furnaces for melting, refining, tempering, and the like;
    (B) If the system is separately derived and is used exclusively for 
rectifiers supplying only adjustable speed industrial drives;
    (C) If the system is separately derived and is supplied by a 
transformer that has a primary voltage rating less than 1000 volts, 
provided all of the following conditions are met:
    (1) The system is used exclusively for control circuits,
    (2) The conditions of maintenance and supervision ensure that only 
qualified persons will service the installation,
    (3) Continuity of control power is required, and
    (4) Ground detectors are installed on the control system;
    (D) If the system is an isolated power system that supplies 
circuits in health care facilities; or
    (E) If the system is a high-impedance grounded neutral system in 
which a grounding impedance, usually a resistor, limits the ground-
fault current to a low value for 3-phase ac systems of 480 volts to 
1000 volts provided all of the following conditions are met:
    (1) The conditions of maintenance and supervision ensure that only 
qualified persons will service the installation,
    (2) Continuity of power is required,
    (3) Ground detectors are installed on the system, and
    (4) Line-to-neutral loads are not served.
    (2) Portable and vehicle-mounted generators. (i) The frame of a 
portable generator need not be grounded and may serve as the grounding 
electrode for a system supplied by the generator under the following 
conditions:
    (A) The generator supplies only equipment mounted on the generator 
or cord- and plug-connected equipment through receptacles mounted on 
the generator, or both; and
    (B) The noncurrent-carrying metal parts of equipment and the 
equipment grounding conductor terminals of the receptacles are bonded 
to the generator frame.
    (ii) The frame of a vehicle need not be grounded and may serve as 
the grounding electrode for a system supplied by a generator located on 
the vehicle under the following conditions:
    (A) The frame of the generator is bonded to the vehicle frame; and
    (B) The generator supplies only equipment located on the vehicle 
and cord- and plug-connected equipment through receptacles mounted on 
the vehicle; and
    (C) The noncurrent-carrying metal parts of equipment and the 
equipment grounding conductor terminals of the receptacles are bonded 
to the generator frame; and
    (D) The system complies with all other provisions of paragraph (g) 
of this section.
    (iii) A neutral conductor shall be bonded to the generator frame 
where the generator is a component of a separately derived system.
    (3) Grounding connections. (i) For a grounded system, a grounding 
electrode conductor shall be used to connect both the equipment 
grounding conductor and the grounded circuit conductor to the grounding 
electrode. Both the equipment grounding conductor and the grounding 
electrode conductor shall be connected to the grounded circuit 
conductor on the supply side of the service disconnecting means or on 
the supply side of the system disconnecting means or overcurrent 
devices if the system is separately derived.
    (ii) For an ungrounded service-supplied system, the equipment 
grounding conductor shall be connected to the grounding electrode 
conductor at the service equipment. For an ungrounded separately 
derived system, the equipment grounding conductor shall be connected to 
the grounding electrode conductor at, or ahead of, the system 
disconnecting means or overcurrent devices.
    (iii) On extensions of existing branch circuits that do not have an 
equipment grounding conductor, grounding-type receptacles may be 
grounded to a grounded cold water pipe near the equipment.
    (4) Grounding path. The path to ground from circuits, equipment, 
and enclosures shall be permanent and continuous.
    (5) Supports, enclosures, and equipment to be grounded. (i) Metal 
cable trays, metal raceways, and metal enclosures for conductors shall 
be grounded, except that:
    (A) Metal enclosures such as sleeves that are used to protect cable 
assemblies

[[Page 17821]]

from physical damage need not be grounded; and
    (B) Metal enclosures for conductors added to existing installations 
of open wire, knob-and-tube wiring, and nonmetallic-sheathed cable need 
not be grounded if all of the following conditions are met:
    (1) Runs are less than 7.62 meters (25.0 ft);
    (2) Enclosures are free from probable contact with ground, grounded 
metal, metal laths, or other conductive materials; and
    (3) Enclosures are guarded against employee contact.
    (ii) Metal enclosures for service equipment shall be grounded.
    (iii) Frames of electric ranges, wall-mounted ovens, counter-
mounted cooking units, clothes dryers, and metal outlet or junction 
boxes that are part of the circuit for these appliances shall be 
grounded.
    (iv) Exposed noncurrent-carrying metal parts of fixed equipment 
that may become energized shall be grounded under any of the following 
conditions:
    (A) If within 2.44 m (8 ft) vertically or 1.52 m (5 ft) 
horizontally of ground or grounded metal objects and subject to 
employee contact;
    (B) If located in a wet or damp location and not isolated;
    (C) If in electrical contact with metal;
    (D) If in a hazardous (classified) location;
    (E) If supplied by a metal-clad, metal-sheathed, or grounded metal 
raceway wiring method; or
    (F) If equipment operates with any terminal at over 150 volts to 
ground.
    (v) Notwithstanding the provisions of paragraph (g)(5)(iv) of this 
section, exposed noncurrent-carrying metal parts of the following types 
of fixed equipment need not be grounded:
    (A) Enclosures for switches or circuit breakers used for other than 
service equipment and accessible to qualified persons only;
    (B) Electrically heated appliances that are permanently and 
effectively insulated from ground;
    (C) Distribution apparatus, such as transformer and capacitor 
cases, mounted on wooden poles, at a height exceeding 2.44 m (8.0 ft) 
above ground or grade level; and
    (D) Listed equipment protected by a system of double insulation, or 
its equivalent, and distinctively marked as such.
    (vi) Exposed noncurrent-carrying metal parts of cord- and plug-
connected equipment that may become energized shall be grounded under 
any of the following conditions:
    (A) If in hazardous (classified) locations (see Sec.  1910.307);
    (B) If operated at over 150 volts to ground, except for guarded 
motors and metal frames of electrically heated appliances if the 
appliance frames are permanently and effectively insulated from ground;
    (C) If the equipment is of the following types:
    (1) Refrigerators, freezers, and air conditioners;
    (2) Clothes-washing, clothes-drying and dishwashing machines, sump 
pumps, and electric aquarium equipment;
    (3) Hand-held motor-operated tools, stationary and fixed motor-
operated tools, and light industrial motor-operated tools;
    (4) Motor-operated appliances of the following types: hedge 
clippers, lawn mowers, snow blowers, and wet scrubbers;
    (5) Cord- and plug-connected appliances used in damp or wet 
locations, or by employees standing on the ground or on metal floors or 
working inside of metal tanks or boilers;
    (6) Portable and mobile X-ray and associated equipment;
    (7) Tools likely to be used in wet and conductive locations; and
    (8) Portable hand lamps.
    (vii) Notwithstanding the provisions of paragraph (g)(5)(vi) of 
this section, the following equipment need not be grounded:
    (A) Tools likely to be used in wet and conductive locations if 
supplied through an isolating transformer with an ungrounded secondary 
of not over 50 volts, and
    (B) Listed or labeled portable tools and appliances if protected by 
an approved system of double insulation, or its equivalent, and 
distinctively marked.
    (6) Nonelectrical equipment. The metal parts of the following 
nonelectrical equipment shall be grounded: Frames and tracks of 
electrically operated cranes and hoists; frames of nonelectrically 
driven elevator cars to which electric conductors are attached; hand-
operated metal shifting ropes or cables of electric elevators; and 
metal partitions, grill work, and similar metal enclosures around 
equipment of over 750 volts between conductors.
    (7) Methods of grounding fixed equipment. (i) Noncurrent-carrying 
metal parts of fixed equipment, if required to be grounded by this 
subpart, shall be grounded by an equipment grounding conductor that is 
contained within the same raceway, cable, or cord, or runs with or 
encloses the circuit conductors. For dc circuits only, the equipment 
grounding conductor may be run separately from the circuit conductors.
    (ii) Electric equipment is considered to be effectively grounded if 
it is secured to, and in electrical contact with, a metal rack or 
structure that is provided for its support and the metal rack or 
structure is grounded by the method specified for the noncurrent-
carrying metal parts of fixed equipment in paragraph (g)(7)(i) of this 
section. Metal car frames supported by metal hoisting cables attached 
to or running over metal sheaves or drums of grounded elevator machines 
are also considered to be effectively grounded. For installations made 
before April 16, 1981, only, electric equipment is also considered to 
be effectively grounded if it is secured to, and in metallic contact 
with, the grounded structural metal frame of a building.
    (8) Grounding of systems and circuits of 1000 volts and over (high 
voltage). If high voltage systems are grounded, they shall comply with 
all applicable provisions of paragraphs (g)(1) through (g)(7) of this 
section as supplemented and modified by the following requirements:
    (i) Systems supplying portable or mobile high voltage equipment, 
other than substations installed on a temporary basis, shall comply 
with the following:
    (A) The system shall have its neutral grounded through an 
impedance. If a delta-connected high voltage system is used to supply 
the equipment, a system neutral shall be derived.
    (B) Exposed noncurrent-carrying metal parts of portable and mobile 
equipment shall be connected by an equipment grounding conductor to the 
point at which the system neutral impedance is grounded.
    (C) Ground-fault detection and relaying shall be provided to 
automatically deenergize any high voltage system component that has 
developed a ground fault. The continuity of the equipment grounding 
conductor shall be continuously monitored so as to deenergize 
automatically the high voltage feeder to the portable equipment upon 
loss of continuity of the equipment grounding conductor.
    (D) The grounding electrode to which the portable equipment system 
neutral impedance is connected shall be isolated from and separated in 
the ground by at least 6.1 m (20.0 ft) from any other system or 
equipment grounding electrode, and there shall be no direct connection 
between the grounding electrodes, such as buried pipe, fence, and so 
forth.

[[Page 17822]]

    (ii) All noncurrent-carrying metal parts of portable equipment and 
fixed equipment, including their associated fences, housings, 
enclosures, and supporting structures, shall be grounded. However, 
equipment that is guarded by location and isolated from ground need not 
be grounded. Additionally, pole-mounted distribution apparatus at a 
height exceeding 2.44 m (8.0 ft) above ground or grade level need not 
be grounded.


Sec.  1910.305  Wiring methods, components, and equipment for general 
use.

    (a) Wiring methods. The provisions of this section do not apply to 
conductors that are an integral part of factory-assembled equipment.
    (1) General requirements. (i) Metal raceways, cable trays, cable 
armor, cable sheath, enclosures, frames, fittings, and other metal 
noncurrent-carrying parts that are to serve as grounding conductors, 
with or without the use of supplementary equipment grounding 
conductors, shall be effectively bonded where necessary to ensure 
electrical continuity and the capacity to conduct safely any fault 
current likely to be imposed on them. Any nonconductive paint, enamel, 
or similar coating shall be removed at threads, contact points, and 
contact surfaces or be connected by means of fittings designed so as to 
make such removal unnecessary.
    (ii) Where necessary for the reduction of electrical noise 
(electromagnetic interference) of the grounding circuit, an equipment 
enclosure supplied by a branch circuit may be isolated from a raceway 
containing circuits supplying only that equipment by one or more listed 
nonmetallic raceway fittings located at the point of attachment of the 
raceway to the equipment enclosure. The metal raceway shall be 
supplemented by an internal insulated equipment grounding conductor 
installed to ground the equipment enclosure.
    (iii) No wiring systems of any type may be installed in ducts used 
to transport dust, loose stock, or flammable vapors. No wiring system 
of any type may be installed in any duct used for vapor removal or for 
ventilation of commercial-type cooking equipment, or in any shaft 
containing only such ducts.
    (2) Temporary wiring. Except as specifically modified in this 
paragraph, all other requirements of this subpart for permanent wiring 
shall also apply to temporary wiring installations.
    (i) Temporary electrical power and lighting installations of 600 
volts, nominal, or less may be used only as follows:
    (A) During and for remodeling, maintenance, or repair of buildings, 
structures, or equipment, and similar activities;
    (B) For a period not to exceed 90 days for Christmas decorative 
lighting, carnivals, and similar purposes; or
    (C) For experimental or development work, and during emergencies.
    (ii) Temporary wiring shall be removed immediately upon completion 
of the project or purpose for which the wiring was installed.
    (iii) Temporary electrical installations of more than 600 volts may 
be used only during periods of tests, experiments, or emergencies.
    (iv) The following requirements apply to feeders:
    (A) Feeders shall originate in an approved distribution center.
    (B) Conductors shall be run as multiconductor cord or cable 
assemblies. However, if installed as permitted in paragraph 
(a)(2)(i)(C) of this section, and if accessible only to qualified 
persons, feeders may be run as single insulated conductors.
    (v) The following requirements apply to branch circuits:
    (A) Branch circuits shall originate in an approved power outlet or 
panelboard.
    (B) Conductors shall be multiconductor cord or cable assemblies or 
open conductors. If run as open conductors they shall be fastened at 
ceiling height every 3.05 m (10.0 ft).
    (C) No branch-circuit conductor may be laid on the floor.
    (D) Each branch circuit that supplies receptacles or fixed 
equipment shall contain a separate equipment grounding conductor if run 
as open conductors.
    (vi) Receptacles shall be of the grounding type. Unless installed 
in a continuous grounded metallic raceway or metallic covered cable, 
each branch circuit shall contain a separate equipment grounding 
conductor and all receptacles shall be electrically connected to the 
grounding conductor.
    (vii) No bare conductors nor earth returns may be used for the 
wiring of any temporary circuit.
    (viii) Suitable disconnecting switches or plug connectors shall be 
installed to permit the disconnection of all ungrounded conductors of 
each temporary circuit. Multiwire branch circuits shall be provided 
with a means to disconnect simultaneously all ungrounded conductors at 
the power outlet or panelboard where the branch circuit originated.

    Note to paragraph (a)(2)(viii) of this section.  Circuit 
breakers with their handles connected by approved handle ties are 
considered a single disconnecting means for the purpose of this 
requirement.

    (ix) All lamps for general illumination shall be protected from 
accidental contact or breakage by a suitable fixture or lampholder with 
a guard. Brass shell, paper-lined sockets, or other metal-cased sockets 
may not be used unless the shell is grounded.
    (x) Flexible cords and cables shall be protected from accidental 
damage, as might be caused, for example, by sharp corners, projections, 
and doorways or other pinch points.
    (xi) Cable assemblies and flexible cords and cables shall be 
supported in place at intervals that ensure that they will be protected 
from physical damage. Support shall be in the form of staples, cables 
ties, straps, or similar type fittings installed so as not to cause 
damage.
    (3) Cable trays. (i) Only the following wiring methods may be 
installed in cable tray systems: Armored cable, electrical metallic 
tubing, electrical nonmetallic tubing, fire alarm cables, flexible 
metal conduit, flexible metallic tubing, instrumentation tray cable, 
intermediate metal conduit, liquidtight flexible metal conduit and 
liquidtight flexible nonmetallic conduit, metal-clad cable, mineral-
insulated, metal-sheathed cable, multiconductor service-entrance cable, 
multiconductor underground feeder and branch-circuit cable, 
multipurpose and communications cables, nonmetallic-sheathed cable, 
power and control tray cable, power-limited tray cable, optical fiber 
cables, other factory-assembled, multiconductor control, signal, or 
power cables that are specifically approved for installation in cable 
trays, rigid metal conduit, and rigid nonmetallic conduit.
    (ii) In industrial establishments where conditions of maintenance 
and supervision assure that only qualified persons will service the 
installed cable tray system, the following cables may also be installed 
in ladder, ventilated-trough, or ventilated-channel cable trays:
    (A) Single conductor cable; the cable shall be No. 1/0 or larger 
and shall be of a type listed and marked on the surface for use in 
cable trays; where Nos. 1/0 through 4/0 single conductor cables are 
installed in ladder cable tray, the maximum allowable rung spacing for 
the ladder cable tray shall be 229 mm (9 in.); where exposed to direct 
rays of the sun, cables shall be identified as being sunlight 
resistant;
    (B) Welding cables installed in dedicated cable trays;
    (C) Single conductors used as equipment grounding conductors; these 
conductors, which may be insulated, covered, or bare, shall be No. 4 or 
larger;

[[Page 17823]]

    (D) Multiconductor cable, Type MV; where exposed to direct rays of 
the sun, the cable shall be identified as being sunlight resistant.
    (iii) Metallic cable trays may be used as equipment grounding 
conductors only where continuous maintenance and supervision ensure 
that qualified persons will service the installed cable tray system.
    (iv) Cable trays in hazardous (classified) locations may contain 
only the cable types permitted in such locations. (See Sec.  1910.307.)
    (v) Nonmetallic cable trays may only be installed in corrosive 
areas and in areas requiring voltage isolation.
    (vi) Cable tray systems may not be used in hoistways or where 
subjected to severe physical damage.
    (4) Open wiring on insulators. (i) Open wiring on insulators is 
only permitted on systems of 600 volts, nominal, or less for industrial 
or agricultural establishments, indoors or outdoors, in wet or dry 
locations, where subject to corrosive vapors, and for services.
    (ii) Conductors smaller than No. 8 shall be rigidly supported on 
noncombustible, nonabsorbent insulating materials and may not contact 
any other objects. Supports shall be installed as follows:
    (A) Within 152 mm (6 in.) from a tap or splice;
    (B) Within 305 mm (12 in.) of a dead-end connection to a lampholder 
or receptacle; and
    (C) At intervals not exceeding 1.37 m (4.5 ft), and at closer 
intervals sufficient to provide adequate support where likely to be 
disturbed.
    (iii) In dry locations, where not exposed to severe physical 
damage, conductors may be separately enclosed in flexible nonmetallic 
tubing. The tubing shall be in continuous lengths not exceeding 4.57 m 
(15.0 ft) and secured to the surface by straps at intervals not 
exceeding 1.37 m (4.5 ft).
    (iv) Open conductors shall be separated from contact with walls, 
floors, wood cross members, or partitions through which they pass by 
tubes or bushings of noncombustible, nonabsorbent insulating material. 
If the bushing is shorter than the hole, a waterproof sleeve of 
nonconductive material shall be inserted in the hole and an insulating 
bushing slipped into the sleeve at each end in such a manner as to keep 
the conductors absolutely out of contact with the sleeve. Each 
conductor shall be carried through a separate tube or sleeve.
    (v) Where open conductors cross ceiling joints and wall studs and 
are exposed to physical damage (for example, located within 2.13 m (7.0 
ft) of the floor), they shall be protected.
    (b) Cabinets, boxes, and fittings--(1) Conductors entering boxes, 
cabinets, or fittings. (i) Conductors entering cutout boxes, cabinets, 
or fittings shall be protected from abrasion, and openings through 
which conductors enter shall be effectively closed.
    (ii) Unused openings in cabinets, boxes, and fittings shall be 
effectively closed.
    (iii) Where cable is used, each cable shall be secured to the 
cabinet, cutout box, or meter socket enclosure. However, where cable 
with an entirely nonmetallic sheath enters the top of a surface-mounted 
enclosure through one or more nonflexible raceways not less than 457 mm 
(18 in.) or more than 3.05 m (10.0 ft) in length, the cable need not be 
secured to the cabinet, box, or enclosure provided all of the following 
conditions are met:
    (A) Each cable is fastened within 305 mm (12 in.) of the outer end 
of the raceway, measured along the sheath;
    (B) The raceway extends directly above the enclosure and does not 
penetrate a structural ceiling;
    (C) A fitting is provided on each end of the raceway to protect the 
cable from abrasion, and the fittings remain accessible after 
installation;
    (D) The raceway is sealed or plugged at the outer end using 
approved means so as to prevent access to the enclosure through the 
raceway;
    (E) The cable sheath is continuous through the raceway and extends 
into the enclosure not less than 6.35 mm (0.25 in.) beyond the fitting;
    (F) The raceway is fastened at its outer end and at other points as 
necessary; and
    (G) Where installed as conduit or tubing, the allowable cable fill 
does not exceed that permitted for complete conduit or tubing systems.
    (2) Covers and canopies. (i) All pull boxes, junction boxes, and 
fittings shall be provided with covers identified for the purpose. If 
metal covers are used they shall be grounded. In completed 
installations each outlet box shall have a cover, faceplate, or fixture 
canopy. Covers of outlet boxes having holes through which flexible cord 
pendants pass shall be provided with bushings designed for the purpose 
or shall have smooth, well-rounded surfaces on which the cords may 
bear.
    (ii) Where a fixture canopy or pan is used, any combustible wall or 
ceiling finish exposed between the edge of the canopy or pan and the 
outlet box shall be covered with noncombustible material.
    (3) Pull and junction boxes for systems over 600 volts, nominal. In 
addition to other requirements in this section, the following 
requirements apply to pull and junction boxes for systems over 600 
volts, nominal:
    (i) Boxes shall provide a complete enclosure for the contained 
conductors or cables.
    (ii) Boxes shall be closed by suitable covers securely fastened in 
place.

    Note to paragraph (b)(3)(ii) of this section: Underground box 
covers that weigh over 45.4 kg (100 lbs) meet this requirement.

    (iii) Covers for boxes shall be permanently marked ``HIGH 
VOLTAGE.'' The marking shall be on the outside of the box cover and 
shall be readily visible and legible.
    (c) Switches--(1) Single-throw knife switches. Single-throw knife 
switches shall be so placed that gravity will not tend to close them. 
Single-throw knife switches approved for use in the inverted position 
shall be provided with a locking device that will ensure that the 
blades remain in the open position when so set.
    (2) Double-throw knife switches. Double-throw knife switches may be 
mounted so that the throw will be either vertical or horizontal. 
However, if the throw is vertical, a locking device shall be provided 
to ensure that the blades remain in the open position when so set.
    (3) Connection of switches. (i) Single-throw knife switches and 
switches with butt contacts shall be connected so that the blades are 
deenergized when the switch is in the open position.
    (ii) Single-throw knife switches, molded-case switches, switches 
with butt contacts, and circuit breakers used as switches shall be 
connected so that the terminals supplying the load are deenergized when 
the switch is in the open position. However, blades and terminals 
supplying the load of a switch may be energized when the switch is in 
the open position where the switch is connected to circuits or 
equipment inherently capable of providing a backfeed source of power. 
For such installations, a permanent sign shall be installed on the 
switch enclosure or immediately adjacent to open switches that reads, 
``WARNING--LOAD SIDE TERMINALS MAY BE ENERGIZED BY BACKFEED.''
    (4) Faceplates for flush-mounted snap switches. Snap switches 
mounted in boxes shall have faceplates installed so as to completely 
cover the opening and seat against the finished surface.
    (5) Grounding. Snap switches, including dimmer switches, shall be 
effectively grounded and shall provide a

[[Page 17824]]

means to ground metal faceplates, whether or not a metal faceplate is 
installed. However, if no grounding means exists within the snap-switch 
enclosure, or where the wiring method does not include or provide an 
equipment ground, a snap switch without a grounding connection is 
permitted for replacement purposes only. Such snap switches shall be 
provided with a faceplate of nonconducting, noncombustible material if 
they are located within reach of conducting floors or other conducting 
surfaces.
    (d) Switchboards and panelboards--(1) Switchboards with exposed 
live parts. Switchboards that have any exposed live parts shall be 
located in permanently dry locations and shall be accessible only to 
qualified persons.
    (2) Panelboard enclosures. Panelboards shall be mounted in 
cabinets, cutout boxes, or enclosures designed for the purpose and 
shall be dead front. However, panelboards other than the dead front 
externally-operable type are permitted where accessible only to 
qualified persons.
    (3) Knife switches mounted in switchboards or panelboards. Exposed 
blades of knife switches mounted in switchboards or panelboards shall 
be dead when open.
    (e) Enclosures for damp or wet locations--(1) Cabinets, cutout 
boxes, fittings, boxes, and panelboard enclosures. Cabinets, cutout 
boxes, fittings, boxes, and panelboard enclosures in damp or wet 
locations shall be installed so as to prevent moisture or water from 
entering and accumulating within the enclosures and shall be mounted so 
there is at least 6.35-mm (0.25-in.) airspace between the enclosure and 
the wall or other supporting surface. However, nonmetallic enclosures 
may be installed without the airspace on a concrete, masonry, tile, or 
similar surface. The enclosures shall be weatherproof in wet locations.
    (2) Switches, circuit breakers, and switchboards. Switches, circuit 
breakers, and switchboards installed in wet locations shall be enclosed 
in weatherproof enclosures.
    (f) Conductors for general wiring--(1) Insulation. All conductors 
used for general wiring shall be insulated unless otherwise permitted 
in this subpart.
    (2) Type. The conductor insulation shall be of a type that is 
approved for the voltage, operating temperature, and location of use.
    (3) Distinguishable. Insulated conductors shall be distinguishable 
by appropriate color or other suitable means as being grounded 
conductors, ungrounded conductors, or equipment grounding conductors.
    (g) Flexible cords and cables--(1) Use of flexible cords and 
cables. (i) Flexible cords and cables shall be approved for conditions 
of use and location.
    (ii) Flexible cords and cables may be used only for:
    (A) Pendants;
    (B) Wiring of fixtures;
    (C) Connection of portable lamps or appliances;
    (D) Portable and mobile signs;
    (E) Elevator cables;
    (F) Wiring of cranes and hoists;
    (G) Connection of stationary equipment to facilitate their frequent 
interchange;
    (H) Prevention of the transmission of noise or vibration;
    (I) Appliances where the fastening means and mechanical connections 
are designed to permit removal for maintenance and repair;
    (J) Data processing cables approved as a part of the data 
processing system;
    (K) Connection of moving parts; and
    (L) Temporary wiring as permitted in paragraph (a)(2) of this 
section.
    (iii) If used as permitted in paragraphs (g)(1)(ii)(C), 
(g)(1)(ii)(G), or (g)(1)(ii)(I) of this section, the flexible cord 
shall be equipped with an attachment plug and shall be energized from 
an approved receptacle outlet.
    (iv) Unless specifically permitted otherwise in paragraph 
(g)(1)(ii) of this section, flexible cords and cables may not be used:
    (A) As a substitute for the fixed wiring of a structure;
    (B) Where run through holes in walls, ceilings, or floors;
    (C) Where run through doorways, windows, or similar openings;
    (D) Where attached to building surfaces;
    (E) Where concealed behind building walls, ceilings, or floors; or
    (F) Where installed in raceways, except as otherwise permitted in 
this subpart.
    (v) Flexible cords used in show windows and showcases shall be Type 
S, SE, SEO, SEOO, SJ, SJE, SJEO, SJEOO, SJO, SJOO, SJT, SJTO, SJTOO, 
SO, SOO, ST, STO, or STOO except for the wiring of chain-supported 
lighting fixtures and supply cords for portable lamps and other 
merchandise being displayed or exhibited.
    (2) Identification, splices, and terminations. (i) A conductor of a 
flexible cord or cable that is used as a grounded conductor or an 
equipment grounding conductor shall be distinguishable from other 
conductors. Types S, SC, SCE, SCT, SE, SEO, SEOO, SJ, SJE, SJEO, SJEOO, 
SJO, SJT, SJTO, SJTOO, SO, SOO, ST, STO, and STOO flexible cords and 
Types G, G-GC, PPE, and W flexible cables shall be durably marked on 
the surface at intervals not exceeding 610 mm (24 in.) with the type 
designation, size, and number of conductors.
    (ii) Flexible cords may be used only in continuous lengths without 
splice or tap. Hard-service cord and junior hard-service cord No. 14 
and larger may be repaired if spliced so that the splice retains the 
insulation, outer sheath properties, and usage characteristics of the 
cord being spliced.
    (iii) Flexible cords and cables shall be connected to devices and 
fittings so that strain relief is provided that will prevent pull from 
being directly transmitted to joints or terminal screws.
    (h) Portable cables over 600 volts, nominal. The following 
requirements apply to portable cables used at more than 600 volts, 
nominal:
    (1) Conductor construction. Multiconductor portable cable for use 
in supplying power to portable or mobile equipment at over 600 volts, 
nominal, shall consist of No. 8 or larger conductors employing flexible 
stranding. However, the minimum size of the insulated ground-check 
conductor of Type G-GC cables shall be No. 10.
    (2) Shielding. Cables operated at over 2,000 volts shall be 
shielded for the purpose of confining the voltage stresses to the 
insulation.
    (3) Equipment grounding conductors. Grounding conductors shall be 
provided.
    (4) Grounding shields. All shields shall be grounded.
    (5) Minimum bending radii. The minimum bending radii for portable 
cables during installation and handling in service shall be adequate to 
prevent damage to the cable.
    (6) Fittings. Connectors used to connect lengths of cable in a run 
shall be of a type that lock firmly together. Provisions shall be made 
to prevent opening or closing these connectors while energized. Strain 
relief shall be provided at connections and terminations.
    (7) Splices. Portable cables may not be operated with splices 
unless the splices are of the permanent molded, vulcanized, or other 
approved type.
    (8) Terminations. Termination enclosures shall be suitably marked 
with a high voltage hazard warning, and terminations shall be 
accessible only to authorized and qualified employees.
    (i) Fixture wires--(1) General. Fixture wires shall be approved for 
the voltage, temperature, and location of use. A fixture wire which is 
used as a grounded conductor shall be identified.

[[Page 17825]]

    (2) Uses permitted. Fixture wires may be used only:
    (i) For installation in lighting fixtures and in similar equipment 
where enclosed or protected and not subject to bending or twisting in 
use; or
    (ii) For connecting lighting fixtures to the branch-circuit 
conductors supplying the fixtures.
    (3) Uses not permitted. Fixture wires may not be used as branch-
circuit conductors except as permitted for Class 1 power limited 
circuits and for fire alarm circuits.
    (j) Equipment for general use--(1) Lighting fixtures, lampholders, 
lamps, and receptacles. (i) Fixtures, lampholders, lamps, rosettes, and 
receptacles may have no live parts normally exposed to employee 
contact. However, rosettes and cleat-type lampholders and receptacles 
located at least 2.44 m (8.0 ft) above the floor may have exposed 
terminals.
    (ii) Handlamps of the portable type supplied through flexible cords 
shall be equipped with a handle of molded composition or other material 
identified for the purpose, and a substantial guard shall be attached 
to the lampholder or the handle. Metal shell, paper-lined lampholders 
may not be used.
    (iii) Lampholders of the screw-shell type shall be installed for 
use as lampholders only. Where supplied by a circuit having a grounded 
conductor, the grounded conductor shall be connected to the screw 
shell. Lampholders installed in wet or damp locations shall be of the 
weatherproof type.
    (iv) Fixtures installed in wet or damp locations shall be 
identified for the purpose and shall be so constructed or installed 
that water cannot enter or accumulate in wireways, lampholders, or 
other electrical parts.
    (2) Receptacles, cord connectors, and attachment plugs (caps). (i) 
All 15- and 20-ampere attachment plugs and connectors shall be 
constructed so that there are no exposed current-carrying parts except 
the prongs, blades, or pins. The cover for wire terminations shall be a 
part that is essential for the operation of an attachment plug or 
connector (dead-front construction). Attachment plugs shall be 
installed so that their prongs, blades, or pins are not energized 
unless inserted into an energized receptacle. No receptacles may be 
installed so as to require an energized attachment plug as its source 
of supply.
    (ii) Receptacles, cord connectors, and attachment plugs shall be 
constructed so that no receptacle or cord connector will accept an 
attachment plug with a different voltage or current rating than that 
for which the device is intended. However, a 20-ampere T-slot 
receptacle or cord connector may accept a 15-ampere attachment plug of 
the same voltage rating.
    (iii) Nongrounding-type receptacles and connectors may not be used 
for grounding-type attachment plugs.
    (iv) A receptacle installed in a wet or damp location shall be 
suitable for the location.
    (v) A receptacle installed outdoors in a location protected from 
the weather or in other damp locations shall have an enclosure for the 
receptacle that is weatherproof when the receptacle is covered 
(attachment plug cap not inserted and receptacle covers closed).

    Note to paragraph (j)(2)(v) of this section. A receptacle is 
considered to be in a location protected from the weather when it is 
located under roofed open porches, canopies, marquees, or the like 
and where it will not be subjected to a beating rain or water 
runoff.

    (vi) A receptacle installed in a wet location where the product 
intended to be plugged into it is not attended while in use (for 
example, sprinkler system controllers, landscape lighting, and holiday 
lights) shall have an enclosure that is weatherproof with the 
attachment plug cap inserted or removed.
    (vii) A receptacle installed in a wet location where the product 
intended to be plugged into it will be attended while in use (for 
example, portable tools) shall have an enclosure that is weatherproof 
when the attachment plug cap is removed.
    (3) Appliances. (i) Appliances may have no live parts normally 
exposed to contact other than parts functioning as open-resistance 
heating elements, such as the heating elements of a toaster, which are 
necessarily exposed.
    (ii) Each appliance shall have a means to disconnect it from all 
ungrounded conductors. If an appliance is supplied by more than one 
source, the disconnecting means shall be grouped and identified.
    (iii) Each electric appliance shall be provided with a nameplate 
giving the identifying name and the rating in volts and amperes, or in 
volts and watts. If the appliance is to be used on a specific frequency 
or frequencies, it shall be so marked. Where motor overload protection 
external to the appliance is required, the appliance shall be so 
marked.
    (iv) Marking shall be located so as to be visible or easily 
accessible after installation.
    (4) Motors. This paragraph applies to motors, motor circuits, and 
controllers.
    (i) If specified in paragraph (j)(4) of this section that one piece 
of equipment shall be ``within sight of'' another piece of equipment, 
the piece of equipment shall be visible and not more than 15.24 m (50.0 
ft) from the other.
    (ii) An individual disconnecting means shall be provided for each 
controller. A disconnecting means shall be located within sight of the 
controller location. However, a single disconnecting means may be 
located adjacent to a group of coordinated controllers mounted adjacent 
to each other on a multi-motor continuous process machine. The 
controller disconnecting means for motor branch circuits over 600 
volts, nominal, may be out of sight of the controller, if the 
controller is marked with a warning label giving the location and 
identification of the disconnecting means that is to be locked in the 
open position.
    (iii) The disconnecting means shall disconnect the motor and the 
controller from all ungrounded supply conductors and shall be so 
designed that no pole can be operated independently.
    (iv) The disconnecting means shall plainly indicate whether it is 
in the open (off) or closed (on) position.
    (v) The disconnecting means shall be readily accessible. If more 
than one disconnect is provided for the same equipment, only one need 
be readily accessible.
    (vi) An individual disconnecting means shall be provided for each 
motor, but a single disconnecting means may be used for a group of 
motors under any one of the following conditions:
    (A) If a number of motors drive several parts of a single machine 
or piece of apparatus, such as a metal or woodworking machine, crane, 
or hoist;
    (B) If a group of motors is under the protection of one set of 
branch-circuit protective devices; or
    (C) If a group of motors is in a single room within sight of the 
location of the disconnecting means.
    (vii) Motors, motor-control apparatus, and motor branch-circuit 
conductors shall be protected against overheating due to motor 
overloads or failure to start, and against short-circuits or ground 
faults. These provisions do not require overload protection that will 
stop a motor where a shutdown is likely to introduce additional or 
increased hazards, as in the case of fire pumps, or where continued 
operation of a motor is necessary for a safe shutdown of equipment or 
process and motor overload sensing devices are connected to a 
supervised alarm.
    (viii) Where live parts of motors or controllers operating at over 
150 volts to ground are guarded against accidental contact only by 
location, and where

[[Page 17826]]

adjustment or other attendance may be necessary during the operation of 
the apparatus, suitable insulating mats or platforms shall be provided 
so that the attendant cannot readily touch live parts unless standing 
on the mats or platforms.
    (5) Transformers. (i) Paragraph (j)(5) of this section covers the 
installation of all transformers except the following:
    (A) Current transformers;
    (B) Dry-type transformers installed as a component part of other 
apparatus;
    (C) Transformers that are an integral part of an X-ray, high 
frequency, or electrostatic-coating apparatus;
    (D) Transformers used with Class 2 and Class 3 circuits, sign and 
outline lighting, electric discharge lighting, and power-limited fire-
alarm circuits; and
    (E) Liquid-filled or dry-type transformers used for research, 
development, or testing, where effective safeguard arrangements are 
provided.
    (ii) The operating voltage of exposed live parts of transformer 
installations shall be indicated by signs or visible markings on the 
equipment or structure.
    (iii) Dry-type, high fire point liquid-insulated, and askarel-
insulated transformers installed indoors and rated over 35kV shall be 
in a vault.
    (iv) Oil-insulated transformers installed indoors shall be 
installed in a vault.
    (v) Combustible material, combustible buildings and parts of 
buildings, fire escapes, and door and window openings shall be 
safeguarded from fires that may originate in oil-insulated transformers 
attached to or adjacent to a building or combustible material.
    (vi) Transformer vaults shall be constructed so as to contain fire 
and combustible liquids within the vault and to prevent unauthorized 
access. Locks and latches shall be so arranged that a vault door can be 
readily opened from the inside.
    (vii) Any pipe or duct system foreign to the electrical 
installation may not enter or pass through a transformer vault.

    Note to paragraph (j)(5)(vii) of this section. Piping or other 
facilities provided for vault fire protection, or for transformer 
cooling, are not considered foreign to the electrical installation.

    (viii) Material may not be stored in transformer vaults.
    (6) Capacitors. (i) All capacitors, except surge capacitors or 
capacitors included as a component part of other apparatus, shall be 
provided with an automatic means of draining the stored charge after 
the capacitor is disconnected from its source of supply.
    (ii) The following requirements apply to capacitors installed on 
circuits operating at more than 600 volts, nominal:
    (A) Group-operated switches shall be used for capacitor switching 
and shall be capable of the following:
    (1) Carrying continuously not less than 135 percent of the rated 
current of the capacitor installation;
    (2) Interrupting the maximum continuous load current of each 
capacitor, capacitor bank, or capacitor installation that will be 
switched as a unit;
    (3) Withstanding the maximum inrush current, including 
contributions from adjacent capacitor installations; and
    (4) Carrying currents due to faults on the capacitor side of the 
switch.
    (B) A means shall be installed to isolate from all sources of 
voltage each capacitor, capacitor bank, or capacitor installation that 
will be removed from service as a unit. The isolating means shall 
provide a visible gap in the electric circuit adequate for the 
operating voltage.
    (C) Isolating or disconnecting switches (with no interrupting 
rating) shall be interlocked with the load interrupting device or shall 
be provided with prominently displayed caution signs to prevent 
switching load current.
    (D) For series capacitors, the proper switching shall be assured by 
use of at least one of the following:
    (1) Mechanically sequenced isolating and bypass switches;
    (2) Interlocks; or
    (3) Switching procedure prominently displayed at the switching 
location.
    (7) Storage Batteries. Provisions shall be made for sufficient 
diffusion and ventilation of gases from storage batteries to prevent 
the accumulation of explosive mixtures.


Sec.  1910.306  Specific purpose equipment and installations.

    (a) Electric signs and outline lighting--(1) Disconnecting means. 
(i) Each sign and outline lighting system, or feeder circuit or branch 
circuit supplying a sign or outline lighting system, shall be 
controlled by an externally operable switch or circuit breaker that 
will open all ungrounded conductors. However, a disconnecting means is 
not required for an exit directional sign located within a building or 
for cord-connected signs with an attachment plug.
    (ii) Signs and outline lighting systems located within fountains 
shall have the disconnect located at least 1.52 m (5.0 ft) from the 
inside walls of the fountain.
    (2) Location. (i) The disconnecting means shall be within sight of 
the sign or outline lighting system that it controls. Where the 
disconnecting means is out of the line of sight from any section that 
may be energized, the disconnecting means shall be capable of being 
locked in the open position.
    (ii) Signs or outline lighting systems operated by electronic or 
electromechanical controllers located external to the sign or outline 
lighting system may have a disconnecting means located within sight of 
the controller or in the same enclosure with the controller. The 
disconnecting means shall disconnect the sign or outline lighting 
system and the controller from all ungrounded supply conductors. It 
shall be designed so no pole can be operated independently and shall be 
capable of being locked in the open position.
    (iii) Doors or covers giving access to uninsulated parts of indoor 
signs or outline lighting exceeding 600 volts and accessible to other 
than qualified persons shall either be provided with interlock switches 
to disconnect the primary circuit or shall be so fastened that the use 
of other than ordinary tools will be necessary to open them.
    (b) Cranes and hoists. This paragraph applies to the installation 
of electric equipment and wiring used in connection with cranes, 
monorail hoists, hoists, and all runways.
    (1) Disconnecting means for runway conductors. A disconnecting 
means shall be provided between the runway contact conductors and the 
power supply. Such disconnecting means shall consist of a motor-circuit 
switch, circuit breaker, or molded case switch. The disconnecting means 
shall open all ungrounded conductor simultaneously and shall be:

    (i) Readily accessible and operable from the ground or floor level,
    (ii) Arranged to be locked in the open position; and
    (iii) Placed within view of the runway contact conductors.

    (2) Disconnecting means for cranes and monorail hoists. (i) Except 
as provided in paragraph (b)(2)(iv) of this section, a motor-circuit 
switch, molded case switch, or circuit breaker shall be provided in the 
leads from the runway contact conductors or other power supply on all 
cranes and monorail hoists.
    (ii) The disconnecting means shall be capable of being locked in 
the open position.
    (iii) Means shall be provided at the operating station to open the 
power circuit to all motors of the crane or monorail hoist where the 
disconnecting means is not readily accessible from the crane or 
monorail hoist operating station.

[[Page 17827]]

    (iv) The disconnecting means may be omitted where a monorail hoist 
or hand-propelled crane bridge installation meets all of the following 
conditions:

    (A) The unit is controlled from the ground or floor level;
    (B) The unit is within view of the power supply disconnecting 
means; and
    (C) No fixed work platform has been provided for servicing the 
unit.
    (3) Limit switch. A limit switch or other device shall be provided 
to prevent the load block from passing the safe upper limit of travel 
of any hoisting mechanism.
    (4) Clearance. The dimension of the working space in the direction 
of access to live parts that may require examination, adjustment, 
servicing, or maintenance while alive shall be a minimum of 762 mm (2.5 
ft). Where controls are enclosed in cabinets, the doors shall either 
open at least 90 degrees or be removable.
    (c) Elevators, dumbwaiters, escalators, moving walks, wheelchair 
lifts, and stairway chair lifts. The following requirements apply to 
elevators, dumbwaiters, escalators, moving walks, wheelchair lifts, and 
stairway chair lifts.
    (1) Disconnecting means. Elevators, dumbwaiters, escalators, moving 
walks, wheelchair lifts, and stairway chair lifts shall have a single 
means for disconnecting all ungrounded main power supply conductors for 
each unit.
    (2) Control panels. Control panels not located in the same space as 
the drive machine shall be located in cabinets with doors or panels 
capable of being locked closed.
    (3) Type. The disconnecting means shall be an enclosed externally 
operable fused motor circuit switch or circuit breaker capable of being 
locked in the open position. The disconnecting means shall be a listed 
device.
    (4) Operation. No provision may be made to open or close this 
disconnecting means from any other part of the premises. If sprinklers 
are installed in hoistways, machine rooms, or machinery spaces, the 
disconnecting means may automatically open the power supply to the 
affected elevators prior to the application of water. No provision may 
be made to close this disconnecting means automatically (that is, power 
may only be restored by manual means).
    (5) Location. The disconnecting means shall be located where it is 
readily accessible to qualified persons.
    (i) On elevators without generator field control, the disconnecting 
means shall be located within sight of the motor controller. Driving 
machines or motion and operation controllers not within sight of the 
disconnecting means shall be provided with a manually operated switch 
installed in the control circuit adjacent to the equipment in order to 
prevent starting. Where the driving machine is located in a remote 
machinery space, a single disconnecting means for disconnecting all 
ungrounded main power supply conductors shall be provided and be 
capable of being locked in the open position.
    (ii) On elevators with generator field control, the disconnecting 
means shall be located within sight of the motor controller for the 
driving motor of the motor-generator set. Driving machines, motor-
generator sets, or motion and operation controllers not within sight of 
the disconnecting means shall be provided with a manually operated 
switch installed in the control circuit to prevent starting. The 
manually operated switch shall be installed adjacent to this equipment. 
Where the driving machine or the motor-generator set is located in a 
remote machinery space, a single means for disconnecting all ungrounded 
main power supply conductors shall be provided and be capable of being 
locked in the open position.
    (iii) On escalators and moving walks, the disconnecting means shall 
be installed in the space where the controller is located.
    (iv) On wheelchair lifts and stairway chair lifts, the 
disconnecting means shall be located within sight of the motor 
controller.
    (6) Identification and signs. (i) Where there is more than one 
driving machine in a machine room, the disconnecting means shall be 
numbered to correspond to the identifying number of the driving machine 
that they control.
    (ii) The disconnecting means shall be provided with a sign to 
identify the location of the supply-side overcurrent protective device.
    (7) Single-car and multicar installations. On single-car and 
multicar installations, equipment receiving electrical power from more 
than one source shall be provided with a disconnecting means for each 
source of electrical power. The disconnecting means shall be within 
sight of the equipment served.
    (8) Warning sign for multiple disconnecting means. A warning sign 
shall be mounted on or next to the disconnecting means where multiple 
disconnecting means are used and parts of the controllers remain 
energized from a source other than the one disconnected. The sign shall 
be clearly legible and shall read ``WARNING--PARTS OF THE CONTROLLER 
ARE NOT DEENERGIZED BY THIS SWITCH.''
    (9) Interconnection between multicar controllers. A warning sign 
worded as required in paragraph (c)(8) of this section shall be mounted 
on or next to the disconnecting means where interconnections between 
controllers are necessary for the operation of the system on multicar 
installations that remain energized from a source other than the one 
disconnected.
    (10) Motor controllers. Motor controllers may be located outside 
the spaces otherwise required by paragraph (c) of this section, 
provided they are in enclosures with doors or removable panels capable 
of being locked closed and the disconnecting means is located adjacent 
to or is an integral part of the motor controller. Motor controller 
enclosures for escalators or moving walks may be located in the 
balustrade on the side located away from the moving steps or moving 
treadway. If the disconnecting means is an integral part of the motor 
controller, it shall be operable without opening the enclosure.
    (d) Electric welders--disconnecting means--(1) Arc welders. A 
disconnecting means shall be provided in the supply circuit for each 
arc welder that is not equipped with a disconnect mounted as an 
integral part of the welder. The disconnecting means shall be a switch 
or circuit breaker, and its rating may not be less than that necessary 
to accommodate overcurrent protection.
    (2) Resistance welder. A switch or circuit breaker shall be 
provided by which each resistance welder and its control equipment can 
be disconnected from the supply circuit. The ampere rating of this 
disconnecting means may not be less than the supply conductor ampacity. 
The supply circuit switch may be used as the welder disconnecting means 
where the circuit supplies only one welder.
    (e) Information technology equipment--disconnecting means. A means 
shall be provided to disconnect power to all electronic equipment in an 
information technology equipment room. There shall also be a similar 
means to disconnect the power to all dedicated heating, ventilating, 
and air-conditioning (HVAC) systems serving the room and to cause all 
required fire/smoke dampers to close. The control for these 
disconnecting means shall be grouped and identified and shall be 
readily accessible at the principal exit doors. A single means to 
control both the electronic equipment and HVAC system is permitted.
    (f) X-ray equipment. This paragraph applies to X-ray equipment.
    (1) Disconnecting means. (i) A disconnecting means shall be 
provided

[[Page 17828]]

in the supply circuit. The disconnecting means shall be operable from a 
location readily accessible from the X-ray control. For equipment 
connected to a 120-volt branch circuit of 30 amperes or less, a 
grounding-type attachment plug cap and receptacle of proper rating may 
serve as a disconnecting means.
    (ii) If more than one piece of equipment is operated from the same 
high-voltage circuit, each piece or each group of equipment as a unit 
shall be provided with a high-voltage switch or equivalent 
disconnecting means. The disconnecting means shall be constructed, 
enclosed, or located so as to avoid contact by employees with its live 
parts.
    (2) Control. The following requirements apply to industrial and 
commercial laboratory equipment. (i) Radiographic and fluoroscopic-type 
equipment shall be effectively enclosed or shall have interlocks that 
deenergize the equipment automatically to prevent ready access to live 
current-carrying parts.
    (ii) Diffraction- and irradiation-type equipment shall have a pilot 
light, readable meter deflection, or equivalent means to indicate when 
the equipment is energized, unless the equipment or installation is 
effectively enclosed or is provided with interlocks to prevent access 
to live current-carrying parts during operation.
    (g) Induction and dielectric heating equipment. This paragraph 
applies to induction and dielectric heating equipment and accessories 
for industrial and scientific applications, but not for medical or 
dental applications or for appliances.
    (1) Guarding and grounding. (i) The converting apparatus (including 
the dc line) and high-frequency electric circuits (excluding the output 
circuits and remote-control circuits) shall be completely contained 
within enclosures of noncombustible material.
    (ii) All panel controls shall be of dead-front construction.
    (iii) Doors or detachable panels shall be employed for internal 
access. Where doors are used giving access to voltages from 500 to 1000 
volts ac or dc, either door locks shall be provided or interlocks shall 
be installed. Where doors are used giving access to voltages of over 
1000 volts ac or dc, either mechanical lockouts with a disconnecting 
means to prevent access until circuit parts within the cubicle are 
deenergized, or both door interlocking and mechanical door locks, shall 
be provided. Detachable panels not normally used for access to such 
parts shall be fastened in a manner that will make them difficult to 
remove (for example, by requiring the use of tools).
    (iv) Warning labels or signs that read ``DANGER--HIGH VOLTAGE--KEEP 
OUT'' shall be attached to the equipment and shall be plainly visible 
where persons might contact energized parts when doors are opened or 
closed or when panels are removed from compartments containing over 250 
volts ac or dc.
    (v) Induction and dielectric heating equipment shall be protected 
as follows:
    (A) Protective cages or adequate shielding shall be used to guard 
work applicators other than induction heating coils.
    (B) Induction heating coils shall be protected by insulation or 
refractory materials or both.
    (C) Interlock switches shall be used on all hinged access doors, 
sliding panels, or other such means of access to the applicator, unless 
the applicator is an induction heating coil at dc ground potential or 
operating at less than 150 volts ac.
    (D) Interlock switches shall be connected in such a manner as to 
remove all power from the applicator when any one of the access doors 
or panels is open.
    (vi) A readily accessible disconnecting means shall be provided by 
which each heating equipment can be isolated from its supply circuit. 
The ampere rating of this disconnecting means may not be less than the 
nameplate current rating of the equipment. The supply circuit 
disconnecting means is permitted as a heating equipment disconnecting 
means where the circuit supplies only one piece of equipment.
    (2) Remote control. (i) If remote controls are used for applying 
power, a selector switch shall be provided and interlocked to provide 
power from only one control point at a time.
    (ii) Switches operated by foot pressure shall be provided with a 
shield over the contact button to avoid accidental closing of the 
switch.
    (h) Electrolytic cells. This paragraph applies to the installation 
of the electrical components and accessory equipment of electrolytic 
cells, electrolytic cell lines, and process power supply for the 
production of aluminum, cadmium, chlorine, copper, fluorine, hydrogen 
peroxide, magnesium, sodium, sodium chlorate, and zinc. Cells used as a 
source of electric energy and for electroplating processes and cells 
used for production of hydrogen are not covered by this paragraph.
    (1) Application. Installations covered by paragraph (h) of this 
section shall comply with all applicable provisions of this subpart, 
except as follows:
    (i) Overcurrent protection of electrolytic cell dc process power 
circuits need not comply with the requirements of Sec.  1910.304(f).
    (ii) Equipment located or used within the cell line working zone or 
associated with the cell line dc power circuits need not comply with 
the provisions of Sec.  1910.304(g).
    (iii) Electrolytic cells, cell line conductors, cell line 
attachments, and the wiring of auxiliary equipment and devices within 
the cell line working zone need not comply with the provisions of Sec.  
1910.303 or Sec.  1910.304(b) and (c).
    (2) Disconnecting means. If more than one dc cell line process 
power supply serves the same cell line, a disconnecting means shall be 
provided on the cell line circuit side of each power supply to 
disconnect it from the cell line circuit. Removable links or removable 
conductors may be used as the disconnecting means.
    (3) Portable electric equipment. (i) The frames and enclosures of 
portable electric equipment used within the cell line working zone may 
not be grounded, unless the cell line circuit voltage does not exceed 
200 volts dc or the frames are guarded.
    (ii) Ungrounded portable electric equipment shall be distinctively 
marked and shall employ plugs and receptacles of a configuration that 
prevents connection of this equipment to grounding receptacles and that 
prevents inadvertent interchange of ungrounded and grounded portable 
electric equipment.
    (4) Power supply circuits and receptacles for portable electric 
equipment. (i) Circuits supplying power to ungrounded receptacles for 
hand-held, cord- and plug-connected equipment shall meet the following 
requirements:
    (A) The circuits shall be electrically isolated from any 
distribution system supplying areas other than the cell line working 
zone and shall be ungrounded;
    (B) The circuits shall be supplied through isolating transformers 
with primaries operating at not more than 600 volts between conductors 
and protected with proper overcurrent protection;
    (C) The secondary voltage of the isolating transformers may not 
exceed 300 volts between conductors; and
    (D) All circuits supplied from the secondaries shall be ungrounded 
and shall have an approved overcurrent device of proper rating in each 
conductor.

[[Page 17829]]

    (ii) Receptacles and their mating plugs for ungrounded equipment 
may not have provision for a grounding conductor and shall be of a 
configuration that prevents their use for equipment required to be 
grounded.
    (iii) Receptacles on circuits supplied by an isolating transformer 
with an ungrounded secondary:
    (A) Shall have a distinctive configuration;
    (B) Shall be distinctively marked; and
    (C) May not be used in any other location in the facility.
    (5) Fixed and portable electric equipment. (i) The following need 
not be grounded:
    (A) AC systems supplying fixed and portable electric equipment 
within the cell line working zone.
    (B) Exposed conductive surfaces, such as electric equipment 
housings, cabinets, boxes, motors, raceways and the like that are 
within the cell line working zone.
    (ii) Auxiliary electric equipment, such as motors, transducers, 
sensors, control devices, and alarms, mounted on an electrolytic cell 
or other energized surface shall be connected to the premises wiring 
systems by any of the following means:
    (A) Multiconductor hard usage or extra hard usage flexible cord;
    (B) Wire or cable in suitable nonmetallic raceways or cable trays; 
or
    (C) Wire or cable in suitable metal raceways or metal cable trays 
installed with insulating breaks such that they will not cause a 
potentially hazardous electrical condition.
    (iii) Fixed electric equipment may be bonded to the energized 
conductive surfaces of the cell line, its attachments, or auxiliaries. 
If fixed electric equipment is mounted on an energized conductive 
surface, it shall be bonded to that surface.
    (6) Auxiliary nonelectrical connections. Auxiliary nonelectrical 
connections such as air hoses, water hoses, and the like, to an 
electrolytic cell, its attachments, or auxiliary equipment may not have 
continuous conductive reinforcing wire, armor, braids, or the like. 
Hoses shall be of a nonconductive material.
    (7) Cranes and hoists. (i) The conductive surfaces of cranes and 
hoists that enter the cell line working zone need not be grounded. The 
portion of an overhead crane or hoist that contacts an energized 
electrolytic cell or energized attachments shall be insulated from 
ground.
    (ii) Remote crane or hoist controls that may introduce hazardous 
electrical conditions into the cell line working zone shall employ one 
or more of the following systems:
    (A) Isolated and ungrounded control circuit;
    (B) Nonconductive rope operator;
    (C) Pendant pushbutton with nonconductive supporting means and with 
nonconductive surfaces or ungrounded exposed conductive surfaces; or
    (D) Radio.
    (i) Electrically driven or controlled irrigation machines--(1) 
Lightning protection. If an irrigation machine has a stationary point, 
a grounding electrode system shall be connected to the machine at the 
stationary point for lightning protection.
    (2) Disconnecting means. (i) The main disconnecting means for a 
center pivot irrigation machine shall be located at the point of 
connection of electrical power to the machine or shall be visible and 
not more than 15.2 m (50 ft) from the machine.
    (ii) The disconnecting means shall be readily accessible and 
capable of being locked in the open position.
    (iii) A disconnecting means shall be provided for each motor and 
controller.
    (j) Swimming pools, fountains, and similar installations. This 
paragraph applies to electric wiring for and equipment in or adjacent 
to all swimming, wading, therapeutic, and decorative pools and 
fountains; hydro-massage bathtubs, whether permanently installed or 
storable; and metallic auxiliary equipment, such as pumps, filters, and 
similar equipment. Therapeutic pools in health care facilities are 
exempt from these provisions.
    (1) Receptacles. (i) A single receptacle of the locking and 
grounding type that provides power for a permanently installed swimming 
pool recirculating pump motor may be located not less than 1.52 m (5 
ft) from the inside walls of a pool. All other receptacles on the 
property shall be located at least 3.05 m (10 ft) from the inside walls 
of a pool.
    (ii) Receptacles that are located within 4.57 m (15 ft), or 6.08 m 
(20 ft) if the installation was built after the effective date of this 
standard, of the inside walls of the pool shall be protected by ground-
fault circuit interrupters.
    (iii) Where a pool is installed permanently at a dwelling unit, at 
least one 125-volt, 15- or 20-ampere receptacle on a general-purpose 
branch circuit shall be located a minimum of 3.05 m (10 ft) and not 
more than 6.08 m (20 ft) from the inside wall of the pool. This 
receptacle shall be located not more than 1.98 m (6.5 ft) above the 
floor, platform, or grade level serving the pool.

    Note to paragraph (j)(1) of this section: In determining these 
dimensions, the distance to be measured is the shortest path the 
supply cord of an appliance connected to the receptacle would follow 
without piercing a floor, wall, or ceiling of a building or other 
effective permanent barrier.

    (2) Lighting fixtures, lighting outlets, and ceiling suspended 
(paddle) fans. (i) In outdoor pool areas, lighting fixtures, lighting 
outlets, and ceiling-suspended (paddle) fans may not be installed over 
the pool or over the area extending 1.52 m (5 ft) horizontally from the 
inside walls of a pool unless no part of the lighting fixture of 
ceiling-suspended (paddle) fan is less than 3.66 m (12 ft) above the 
maximum water level. However, a lighting fixture or lighting outlet 
that was installed before April 16, 1981, may be located less than 1.52 
m (5 ft) measured horizontally from the inside walls of a pool if it is 
at least 1.52 m (5 ft) above the surface of the maximum water level and 
is rigidly attached to the existing structure. It shall also be 
protected by a ground-fault circuit interrupter installed in the branch 
circuit supplying the fixture.
    (ii) Lighting fixtures and lighting outlets installed in the area 
extending between 1.52 m (5 ft) and 3.05 m (10 ft) horizontally from 
the inside walls of a pool shall be protected by a ground-fault circuit 
interrupter unless installed 1.52 m (5 ft) above the maximum water 
level and rigidly attached to the structure adjacent to or enclosing 
the pool.
    (3) Cord- and plug-connected equipment. Flexible cords used with 
the following equipment may not exceed 0.9 m (3 ft) in length and shall 
have a copper equipment grounding conductor with a grounding-type 
attachment plug:
    (i) Cord- and plug-connected lighting fixtures installed within 
4.88 m (16 ft) of the water surface of permanently installed pools; and
    (ii) Other cord- and plug-connected, fixed or stationary equipment 
used with permanently installed pools.
    (4) Underwater equipment. (i) A ground-fault circuit interrupter 
shall be installed in the branch circuit supplying underwater fixtures 
operating at more than 15 volts. Equipment installed underwater shall 
be identified for the purpose.
    (ii) No underwater lighting fixtures may be installed for operation 
at over 150 volts between conductors.
    (iii) A lighting fixture facing upward shall have the lens 
adequately guarded to prevent contact by any person.
    (5) Fountains. All electric equipment, including power supply 
cords, operating at more than 15 volts and used with fountains shall be 
protected by ground-fault circuit interrupters.

[[Page 17830]]

    (k) Carnivals, circuses, fairs, and similar events. This paragraph 
covers the installation of portable wiring and equipment, including 
wiring in or on all structures, for carnivals, circuses, exhibitions, 
fairs, traveling attractions, and similar events.
    (1) Protection of electric equipment. Electric equipment and wiring 
methods in or on rides, concessions, or other units shall be provided 
with mechanical protection where such equipment or wiring methods are 
subject to physical damage.
    (2) Installation. (i) Services shall be installed in accordance 
with applicable requirements of this subpart, and, in addition, shall 
comply with the following:
    (A) Service equipment may not be installed in a location that is 
accessible to unqualified persons, unless the equipment is lockable.
    (B) Service equipment shall be mounted on solid backing and 
installed so as to be protected from the weather, unless the equipment 
is of weatherproof construction.
    (ii) Amusement rides and amusement attractions shall be maintained 
not less than 4.57 m (15 ft) in any direction from overhead conductors 
operating at 600 volts or less, except for the conductors supplying the 
amusement ride or attraction. Amusement rides or attractions may not be 
located under or within 4.57 m (15 ft) horizontally of conductors 
operating in excess of 600 volts.
    (iii) Flexible cords and cables shall be listed for extra-hard 
usage. When used outdoors, flexible cords and cables shall also be 
listed for wet locations and shall be sunlight resistant.
    (iv) Single conductor cable shall be size No. 2 or larger.
    (v) Open conductors are prohibited except as part of a listed 
assembly or festoon lighting installed in accordance with Sec.  
1910.304(c).
    (vi) Flexible cords and cables shall be continuous without splice 
or tap between boxes or fittings. Cord connectors may not be laid on 
the ground unless listed for wet locations. Connectors and cable 
connections may not be placed in audience traffic paths or within areas 
accessible to the public unless guarded.
    (vii) Wiring for an amusement ride, attraction, tent, or similar 
structure may not be supported by another ride or structure unless 
specifically identified for the purpose.
    (viii) Flexible cords and cables run on the ground, where 
accessible to the public, shall be covered with approved nonconductive 
mats. Cables and mats shall be arranged so as not to present a tripping 
hazard.
    (ix) A box or fitting shall be installed at each connection point, 
outlet, switch point, or junction point.
    (3) Inside tents and concessions. Electrical wiring for temporary 
lighting, where installed inside of tents and concessions, shall be 
securely installed, and, where subject to physical damage, shall be 
provided with mechanical protection. All temporary lamps for general 
illumination shall be protected from accidental breakage by a suitable 
fixture or lampholder with a guard.
    (4) Portable distribution and termination boxes. Employers may only 
use portable distribution and termination boxes that meet the following 
requirements:
    (i) Boxes shall be designed so that no live parts are exposed to 
accidental contact. Where installed outdoors the box shall be of 
weatherproof construction and mounted so that the bottom of the 
enclosure is not less 152 mm (6 in.) above the ground.
    (ii) Busbars shall have an ampere rating not less than the 
overcurrent device supplying the feeder supplying the box. Busbar 
connectors shall be provided where conductors terminate directly on 
busbars.
    (iii) Receptacles shall have overcurrent protection installed 
within the box. The overcurrent protection may not exceed the ampere 
rating of the receptacle, except as permitted in Sec.  1910.305(j)(4) 
for motor loads.
    (iv) Where single-pole connectors are used, they shall comply with 
the following:
    (A) Where ac single-pole portable cable connectors are used, they 
shall be listed and of the locking type. Where paralleled sets of 
current-carrying single-pole separable connectors are provided as input 
devices, they shall be prominently labeled with a warning indicating 
the presence of internal parallel connections. The use of single-pole 
separable connectors shall comply with at least one of the following 
conditions:
    (1) Connection and disconnection of connectors are only possible 
where the supply connectors are interlocked to the source and it is not 
possible to connect or disconnect connectors when the supply is 
energized; or
    (2) Line connectors are of the listed sequential-interlocking type 
so that load connectors are connected in the following sequence:
    (i) Equipment grounding conductor connection;
    (ii) Grounded circuit-conductor connection, if provided;
    (iii) Ungrounded conductor connection; and so that disconnection is 
in the reverse order; or
    (3) A caution notice is provided adjacent to the line connectors 
indicating that plug connection must be in the following sequence:
    (i) Equipment grounding conductor connection;
    (ii) Grounded circuit-conductor connection, if provided;
    (iii) Ungrounded conductor connection; and indicating that 
disconnection is in the reverse order.
    (B) Single-pole separable connectors used in portable professional 
motion picture and television equipment may be interchangeable for ac 
or dc use or for different current ratings on the same premises only if 
they are listed for ac/dc use and marked to identify the system to 
which they are connected.
    (v) Overcurrent protection of equipment and conductors shall be 
provided.
    (vi) The following equipment connected to the same source shall be 
bonded:
    (A) Metal raceways and metal sheathed cable,
    (B) Metal enclosures of electrical equipment, and
    (C) Metal frames and metal parts of rides, concessions, trailers, 
trucks, or other equipment that contain or support electrical 
equipment.
    (5) Disconnecting means. (i) Each ride and concession shall be 
provided with a fused disconnect switch or circuit breaker located 
within sight and within 1.83 m (6 ft) of the operator's station.
    (ii) The disconnecting means shall be readily accessible to the 
operator, including when the ride is in operation.
    (iii) Where accessible to unqualified persons, the enclosure for 
the switch or circuit breaker shall be of the lockable type.
    (iv) A shunt trip device that opens the fused disconnect or circuit 
breaker when a switch located in the ride operator's console is closed 
is a permissible method of opening the circuit.


Sec.  1910.307  Hazardous (classified) locations.

    (a) Scope. (1) This section covers the requirements for electric 
equipment and wiring in locations that are classified depending on the 
properties of the flammable vapors, liquids or gases, or combustible 
dusts or fibers that may be present therein and the likelihood that a 
flammable or combustible concentration or quantity is present. 
Hazardous (classified) locations may be found in occupancies such as, 
but not limited to, the following: aircraft

[[Page 17831]]

hangars, gasoline dispensing and service stations, bulk storage plants 
for gasoline or other volatile flammable liquids, paint-finishing 
process plants, health care facilities, agricultural or other 
facilities where excessive combustible dusts may be present, marinas, 
boat yards, and petroleum and chemical processing plants. Each room, 
section or area shall be considered individually in determining its 
classification.
    (2) These hazardous (classified) locations are assigned the 
following designations:
    Class I, Division 1;
    Class I, Division 2;
    Class I, Zone 0;
    Class I, Zone 1;
    Class I, Zone 2;
    Class II, Division 1;
    Class II, Division 2;
    Class III, Division 1;
    Class III, Division 2.
    For definitions of these locations see Sec.  1910.399.
    (3) All applicable requirements in this subpart apply to hazardous 
(classified) locations unless modified by provisions of this section.
    (4) In Class I locations, an installation must be classified as 
using the division classification system meeting paragraphs (c), (d), 
(e) and (f) of this section or using the zone classification system 
meeting paragraph (g) of this section. In Class II and Class III 
locations, an installation must be classified using the division 
classification system meeting paragraphs (c), (d), (e) and (f) of this 
section.
    (b) Documentation. All areas designated as hazardous (classified) 
locations under the Class and Zone system and areas designated under 
the Class and Division system established after the effective date of 
the standard shall be properly documented. This documentation shall be 
available to those authorized to design, install, inspect, maintain, or 
operate electric equipment at the location.
    (c) Electrical installations. Equipment, wiring methods, and 
installations of equipment in hazardous (classified) locations shall be 
intrinsically safe, approved for the hazardous (classified) location, 
or safe for the hazardous (classified) location. Requirements for each 
of these options are as follows:
    (1) Intrinsically safe. Equipment and associated wiring approved as 
intrinsically safe is permitted in any hazardous (classified) location 
for which it is approved.
    (2) Approved for the hazardous (classified) location. (i) Equipment 
shall be approved not only for the class of location, but also for the 
ignitable or combustible properties of the specific gas, vapor, dust, 
or fiber that will be present.

    Note to paragraph (c)(2)(i) of this section: NFPA 70, the 
National Electrical Code, lists or defines hazardous gases, vapors, 
and dusts by ``Groups'' characterized by their ignitable or 
combustible properties.

    (ii) Equipment shall be marked to show the class, group, and 
operating temperature or temperature range, based on operation in a 40-
degree C ambient, for which it is approved. The temperature marking may 
not exceed the ignition temperature of the specific gas or vapor to be 
encountered. However, the following provisions modify this marking 
requirement for specific equipment:
    (A) Equipment of the nonheat-producing type, such as junction 
boxes, conduit, and fittings, and equipment of the heat-producing type 
having a maximum temperature not more than 100 [deg]C (212 [deg]F) need 
not have a marked operating temperature or temperature range.
    (B) Fixed lighting fixtures marked for use in Class I, Division 2 
or Class II, Division 2 locations only need not be marked to indicate 
the group.
    (C) Fixed general-purpose equipment in Class I locations, other 
than lighting fixtures, that is acceptable for use in Class I, Division 
2 locations need not be marked with the class, group, division, or 
operating temperature.
    (D) Fixed dust-tight equipment, other than lighting fixtures, that 
is acceptable for use in Class II, Division 2 and Class III locations 
need not be marked with the class, group, division, or operating 
temperature.
    (E) Electric equipment suitable for ambient temperatures exceeding 
40 [deg]C (104 [deg]F) shall be marked with both the maximum ambient 
temperature and the operating temperature or temperature range at that 
ambient temperature.
    (3) Safe for the hazardous (classified) location. Equipment that is 
safe for the location shall be of a type and design that the employer 
demonstrates will provide protection from the hazards arising from the 
combustibility and flammability of vapors, liquids, gases, dusts, or 
fibers.

    Note to paragraph (c)(3) of this section: The National 
Electrical Code, NFPA 70, contains guidelines for determining the 
type and design of equipment and installations that will meet this 
requirement. Those guidelines address electric wiring, equipment, 
and systems installed in hazardous (classified) locations and 
contain specific provisions for the following: wiring methods, 
wiring connections; conductor insulation, flexible cords, sealing 
and drainage, transformers, capacitors, switches, circuit breakers, 
fuses, motor controllers, receptacles, attachment plugs, meters, 
relays, instruments, resistors, generators, motors, lighting 
fixtures, storage battery charging equipment, electric cranes, 
electric hoists and similar equipment, utilization equipment, 
signaling systems, alarm systems, remote control systems, local loud 
speaker and communication systems, ventilation piping, live parts, 
lightning surge protection, and grounding.

    (d) Conduits. All conduits shall be threaded and shall be made 
wrench-tight. Where it is impractical to make a threaded joint tight, a 
bonding jumper shall be utilized.
    (e) Equipment in Division 2 locations. Equipment that has been 
approved for a Division 1 location may be installed in a Division 2 
location of the same class and group. General-purpose equipment or 
equipment in general-purpose enclosures may be installed in Division 2 
locations if the employer can demonstrate that the equipment does not 
constitute a source of ignition under normal operating conditions.
    (f) Protection techniques. The following are acceptable protection 
techniques for electric and electronic equipment in hazardous 
(classified) locations.
    (1) Explosionproof apparatus. This protection technique is 
permitted for equipment in the Class I, Division 1 and 2 locations for 
which it is approved.
    (2) Dust ignitionproof. This protection technique is permitted for 
equipment in the Class II, Division 1 and 2 locations for which it is 
approved.
    (3) Dust-tight. This protection technique is permitted for 
equipment in the Class II, Division 2 and Class III locations for which 
it is approved.
    (4) Purged and pressurized. This protection technique is permitted 
for equipment in any hazardous (classified) location for which it is 
approved.
    (5) Other protection techniques. Any other protection technique 
that meets paragraph (c) of this section is acceptable in any hazardous 
(classified) location.
    (g) Class I, Zone 0, 1, and 2 locations--(1) Scope. Employers may 
use the zone classification system as an alternative to the division 
classification system for electric and electronic equipment and wiring 
for all voltage in Class I, Zone 0, Zone 1, and Zone 2 hazardous 
(classified) locations where fire or explosion hazards may exist due to 
flammable gases, vapors, or liquids.
    (2) Location and general requirements. (i) Locations shall be 
classified depending on the properties of the flammable vapors, 
liquids, or gases that may be present and the likelihood that a 
flammable or

[[Page 17832]]

combustible concentration or quantity is present. Where pyrophoric 
materials are the only materials used or handled, these locations need 
not be classified.
    (ii) Each room, section, or area shall be considered individually 
in determining its classification.
    (iii) All threaded conduit shall be threaded with an NPT standard 
conduit cutting die that provides \3/4\-in. taper per foot. The conduit 
shall be made wrench tight to prevent sparking when fault current flows 
through the conduit system and to ensure the explosionproof or 
flameproof integrity of the conduit system where applicable.
    (iv) Equipment provided with threaded entries for field wiring 
connection shall be installed in accordance with paragraph 
(g)(2)(iv)(A) or (g)(2)(iv)(B) of this section.
    (A) For equipment provided with threaded entries for NPT threaded 
conduit or fittings, listed conduit, conduit fittings, or cable 
fittings shall be used.
    (B) For equipment with metric threaded entries, such entries shall 
be identified as being metric, or listed adaptors to permit connection 
to conduit of NPT-threaded fittings shall be provided with the 
equipment. Adapters shall be used for connection to conduit or NPT-
threaded fittings.
    (3) Protection techniques. One or more of the following protection 
techniques shall be used for electric and electronic equipment in 
hazardous (classified) locations classified under the zone 
classification system:
    (i) Flameproof ``d''--This protection technique is permitted for 
equipment in the Class I, Zone 1 locations for which it is approved.
    (ii) Purged and pressurized--This protection technique is permitted 
for equipment in the Class I, Zone 1 or Zone 2 locations for which it 
is approved.
    (iii) Intrinsic safety--This protection technique is permitted for 
equipment in the Class I, Zone 0 or Zone 1 locations for which it is 
approved.
    (iv) Type of protection ``n''--This protection technique is 
permitted for equipment in the Class I, Zone 2 locations for which it 
is approved. Type of protection ``n'' is further subdivided into nA, 
nC, and nR.
    (v) Oil Immersion ``o''--This protection technique is permitted for 
equipment in the Class I, Zone 1 locations for which it is approved.
    (vi) Increased safety ``e''--This protection technique is permitted 
for equipment in the Class I, Zone 1 locations for which it is 
approved.
    (vii) Encapsulation ``m''--This protection technique is permitted 
for equipment in the Class I, Zone 1 locations for which it is 
approved.
    (viii) Powder Filling ``q''--This protection technique is permitted 
for equipment in the Class I, Zone 1 locations for which it is 
approved.
    (4) Special precaution. Paragraph (g) of this section requires 
equipment construction and installation that will ensure safe 
performance under conditions of proper use and maintenance.

    Note to paragraph (g)(4) of this section: Low ambient conditions 
require special consideration. Electric equipment depending on the 
protection techniques described by paragraph (g)(3)(i) of this 
section may not be suitable for use at temperatures lower than -
20[deg] C (-13[deg] F) unless they are approved for use at lower 
temperatures. However, at low ambient temperatures, flammable 
concentrations of vapors may not exist in a location classified 
Class I, Zone 0, 1, or 2 at normal ambient temperature.

    (i) Classification of areas and selection of equipment and wiring 
methods shall be under the supervision of a qualified registered 
professional engineer.
    (ii) In instances of areas within the same facility classified 
separately, Class I, Zone 2 locations may abut, but not overlap, Class 
I, Division 2 locations. Class I, Zone 0 or Zone 1 locations may not 
abut Class I, Division 1 or Division 2 locations.
    (iii) A Class I, Division 1 or Division 2 location may be 
reclassified as a Class I, Zone 0, Zone 1, or Zone 2 location only if 
all of the space that is classified because of a single flammable gas 
or vapor source is reclassified.
    (5) Listing and marking. (i) Equipment that is listed for a Zone 0 
location may be installed in a Zone 1 or Zone 2 location of the same 
gas or vapor. Equipment that is listed for a Zone 1 location may be 
installed in a Zone 2 location of the same gas or vapor.
    (ii) Equipment shall be marked in accordance with paragraph 
(g)(5)(ii)(A), and (g)(5)(ii)(B) of this section.
    (A) Equipment approved for Class I, Division 1 or Class 1, Division 
2 shall, in addition to being marked in accordance with (c)(2)(ii), be 
marked with the following:
    (1) Class I, Zone 1 or Class I, Zone 2 (as applicable);
    (2) Applicable gas classification groups; and
    (3) Temperature classification; or
    (B) Equipment meeting one or more of the protection techniques 
described in paragraph (g)(3) of this section shall be marked with the 
following in the order shown:
    (1) Class, except for intrinsically safe apparatus;
    (2) Zone, except for intrinsically safe apparatus;
    (3) Symbol ``AEx;''
    (4) Protection techniques;
    (5) Applicable gas classification groups; and
    (6) Temperature classification, except for intrinsically safe 
apparatus.

    Note to paragraph (g)(5)(ii)(B) of this section: An example of 
such a required marking is ``Class I, Zone 0, AEx ia IIC T6.'' See 
Figure S-1 for an explanation of this marking.


[[Page 17833]]


[GRAPHIC] [TIFF OMITTED] TP05AP04.011

Sec.  1910.308  Special systems.

    (a) Systems over 600 volts, nominal. This paragraph covers the 
general requirements for all circuits and equipment operated at over 
600 volts.
    (1) Aboveground wiring methods. (i) Aboveground conductors shall be 
installed in rigid metal conduit, in intermediate metal conduit, in 
electrical metallic tubing, in rigid nonmetallic conduit, in cable 
trays, as busways, as cablebus, in other identified raceways, or as 
open runs of metal-clad cable suitable for the use and purpose. In 
locations accessible to qualified persons only, open runs of Type MV 
cables, bare conductors, and bare busbars are also permitted. Busbars 
shall be either copper or aluminum. Open runs of insulated wires and 
cables having a bare lead sheath or a braided outer covering shall be 
supported in a manner designed to prevent physical damage to the braid 
or sheath.
    (ii) Conductors emerging from the ground shall be enclosed in 
approved raceways.
    (2) Braid-covered insulated conductors-open installations. The 
braid on open runs of braid-covered insulated conductors shall be flame 
retardant or shall have a flame-retardant saturant applied after 
installation. This treated braid covering shall be stripped back a safe 
distance at conductor terminals, according to the operating voltage.
    (3) Insulation shielding. (i) Metallic and semiconductor insulation 
shielding components of shielded cables shall be removed for a distance 
dependent on the circuit voltage and insulation. Stress reduction means 
shall be provided at all terminations of factory-applied shielding.
    (ii) Metallic shielding components such as tapes, wires, or braids, 
or combinations thereof, and their associated conducting and 
semiconducting components shall be grounded.
    (4) Moisture or mechanical protection for metal-sheathed cables. 
Where cable conductors emerge from a metal sheath and where protection 
against moisture or physical damage is necessary, the insulation of the 
conductors shall be protected by a cable sheath terminating device.
    (5) Interrupting and isolating devices. (i) Circuit breaker 
installations located indoors shall consist of metal-enclosed units or 
fire-resistant cell-mounted units. In locations accessible only to 
qualified employees, open mounting of circuit breakers is permitted. A 
means of indicating the open and closed position of circuit breakers 
shall be provided.
    (ii) Where fuses are used to protect conductors and equipment, a 
fuse shall be placed in each ungrounded conductor. Two power fuses may 
be used in parallel to protect the same load, if both fuses have 
identical ratings, and if both fuses are installed in an identified 
common mounting with electrical connections that will divide the 
current equally. Power fuses of the vented type may not be used 
indoors, underground, or in metal enclosures unless identified for the 
use.
    (iii) Fused cutouts installed in buildings or transformer vaults 
shall be of a type identified for the purpose. Distribution cutouts may 
not be used indoors, underground, or in metal enclosures. They shall be 
readily accessible for fuse replacement.
    (iv) Where fused cutouts are not suitable to interrupt the circuit 
manually while carrying full load, an approved means shall be installed 
to interrupt the entire load. Unless the fused cutouts are interlocked 
with the switch to prevent opening of the cutouts under load, a 
conspicuous sign shall be placed at such cutouts reading: ``WARNING--DO 
NOT OPERATE UNDER LOAD.''
    (v) Suitable barriers or enclosures shall be provided to prevent 
contact with nonshielded cables or energized parts of oil-filled 
cutouts.
    (vi) Load interrupter switches may be used only if suitable fuses 
or circuits are used in conjunction with these devices to interrupt 
fault currents.
    (A) Where these devices are used in combination, they shall be 
coordinated electrically so that they will safely withstand the effects 
of closing, carrying, or interrupting all possible currents up to the 
assigned maximum short-circuit rating.
    (B) Where more than one switch is installed with interconnected 
load terminals to provide for alternate connection to different supply 
conductors, each switch shall be provided with a conspicuous sign 
reading: ``WARNING--SWITCH MAY BE ENERGIZED BY BACKFEED.''
    (vii) A means (for example, a fuseholder and fuse designed for the 
purpose) shall be provided to completely isolate equipment for 
inspection and repairs. Isolating means that are not designed to 
interrupt the load current of the circuit shall be either interlocked 
with an approved circuit interrupter or provided with a sign warning 
against opening them under load.
    (6) Mobile and portable equipment. (i) A metallic enclosure shall 
be provided on the mobile machine for enclosing the terminals of the 
power cable. The enclosure shall include provisions for a solid 
connection for the grounding terminal to effectively ground the machine 
frame. The method of cable

[[Page 17834]]

termination used shall prevent any strain or pull on the cable from 
stressing the electrical connections. The enclosure shall have 
provision for locking so only authorized qualified persons may open it 
and shall be marked with a sign warning of the presence of energized 
parts.
    (ii) All energized switching and control parts shall be enclosed in 
effectively grounded metal cabinets or enclosures. Circuit breakers and 
protective equipment shall have the operating means projecting through 
the metal cabinet or enclosure so these units can be reset without 
locked doors being opened. Enclosures and metal cabinets shall be 
locked so that only authorized qualified persons have access and shall 
be marked with a sign warning of the presence of energized parts. 
Collector ring assemblies on revolving-type machines (shovels, 
draglines, etc.) shall be guarded.
    (7) Tunnel installations. This paragraph applies to installation 
and use of high-voltage power distribution and utilization equipment 
that is portable or mobile, such as substations, trailers, cars, mobile 
shovels, draglines, hoists, drills, dredges, compressors, pumps, 
conveyors, and underground excavators.
    (i) Conductors in tunnels shall be installed in one or more of the 
following:
    (A) Metal conduit or other metal raceway;
    (B) Type MC cable; or
    (C) Other approved multiconductor cable.
    (ii) Multiconductor portable cable may supply mobile equipment.
    (iii) Conductors and cables shall also be so located or guarded as 
to protect them from physical damage. An equipment grounding conductor 
shall be run with circuit conductors inside the metal raceway or inside 
the multiconductor cable jacket. The equipment grounding conductor may 
be insulated or bare.
    (iv) Bare terminals of transformers, switches, motor controllers, 
and other equipment shall be enclosed to prevent accidental contact 
with energized parts.
    (v) Enclosures for use in tunnels shall be drip-proof, 
weatherproof, or submersible as required by the environmental 
conditions.
    (vi) Switch or contactor enclosures may not be used as junction 
boxes or raceways for conductors feeding through or tapping off to 
other switches, unless special designs are used to provide adequate 
space for this purpose.
    (vii) A disconnecting means that simultaneously opens all 
ungrounded conductors shall be installed at each transformer or motor 
location.
    (viii) All nonenergized metal parts of electric equipment and metal 
raceways and cable sheaths shall be effectively grounded and bonded to 
all metal pipes and rails at the portal and at intervals not exceeding 
305 m (1000 ft) throughout the tunnel.
    (b) Emergency power systems. This paragraph applies to circuits, 
systems, and equipment intended to supply power for illumination and 
special loads in the event of failure of the normal supply.
    (1) Wiring methods. Emergency circuit wiring shall be kept entirely 
independent of all other wiring and equipment and may not enter the 
same raceway, cable, box, or cabinet or other wiring except either 
where common circuit elements suitable for the purpose are required, or 
for transferring power from the normal to the emergency source.
    (2) Emergency illumination. Emergency illumination shall include 
all required means of egress lighting, illuminated exit signs, and all 
other lights necessary to provide illumination. Where emergency 
lighting is necessary, the system shall be so arranged that the failure 
of any individual lighting element, such as the burning out of a light 
bulb, cannot leave any space in total darkness.
    (3) Signs. (i) A sign shall be placed at the service entrance 
equipment indicating the type and location of on-site emergency power 
sources. However, a sign is not required for individual unit equipment.
    (ii) Where the grounded circuit conductor connected to the 
emergency source is connected to a grounding electrode conductor at a 
location remote from the emergency source, there shall be a sign at the 
grounding location that shall identify all emergency and normal sources 
connected at that location.
    (c) Class 1, Class 2, and Class 3 remote control, signaling, and 
power-limited circuits--(1) Classification. Class 1, Class 2, and Class 
3 remote control, signaling, or power-limited circuits are 
characterized by their usage and electrical power limitation that 
differentiates them from light and power circuits. These circuits are 
classified in accordance with their respective voltage and power 
limitations as summarized in paragraphs (c)(1)(i) through (c)(1)(iii) 
of this section.
    (i) A Class 1 power-limited circuit shall be supplied from a source 
having a rated output of not more than 30 volts and 1000 volt-amperes.
    (ii) A Class 1 remote control circuit or a Class 1 signaling 
circuit shall have a voltage not exceeding 600 volts; however, the 
power output of the source need not be limited.
    (iii) The power source for a Class 2 or Class 3 circuit shall be 
listed equipment marked as a Class 2 or Class 3 power source, except as 
follows:
    (A) Thermocouples do not require listing as a Class 2 power source; 
and
    (B) A dry cell battery is considered an inherently limited Class 2 
power source, provided the voltage is 30 volts or less and the capacity 
is less than or equal to that available from series-connected No. 6 
carbon zinc cells.
    (2) Marking. A Class 2 or Class 3 power supply unit shall be 
durably marked where plainly visible to indicate the class of supply 
and its electrical rating.
    (3) Separation from conductors of other circuits. Cables and 
conductors of Class 2 and Class 3 circuits may not be placed in any 
cable, cable tray, compartment, enclosure, manhole, outlet box, device 
box, raceway, or similar fitting with conductors of electric light, 
power, Class 1, nonpower-limited fire alarm circuits, and medium power 
network-powered broadband communications cables.
    (d) Fire alarm systems--(1) Classifications. Fire alarm circuits 
shall be classified either as nonpower limited or power limited.
    (2) Power sources. The power sources for use with fire alarm 
circuits shall be either power limited or nonlimited as follows:
    (i) The power source of nonpower-limited fire alarm (NPLFA) 
circuits shall have an output voltage of not more than 600 volts, 
nominal.
    (ii) The power source for a power-limited fire alarm (PLFA) circuit 
shall be listed equipment marked as a PLFA power source.
    (3) Separation from conductors of other circuits. (i) Nonpower-
limited fire alarm circuits and Class 1 circuits may occupy the same 
enclosure, cable, or raceway provided all conductors are insulated for 
maximum voltage of any conductor within the enclosure, cable, or 
raceway. Power supply and fire alarm circuit conductors are permitted 
in the same enclosure, cable, or raceway only if connected to the same 
equipment.
    (ii) Power-limited circuit cables and conductors may not be placed 
in any cable, cable tray, compartment, enclosure, outlet box, raceway, 
or similar fitting with conductors of electric light, power, Class 1, 
nonpower-limited fire alarm circuit conductors, or medium power 
network-powered broadband communications circuits.
    (iii) Power-limited fire alarm circuit conductors shall be 
separated at least

[[Page 17835]]

50.8 mm (2 in.) from conductors of any electric light, power, Class 1, 
nonpower-limited fire alarm, or medium power network-powered broadband 
communications circuits.
    (iv) Conductors of one or more Class 2 circuits are permitted 
within the same cable, enclosure, or raceway with conductors of power-
limited fire alarm circuits provided that the insulation of Class 2 
circuit conductors in the cable, enclosure, or raceway is at least that 
needed for the power-limited fire alarm circuits.
    (4) Identification. Fire alarm circuits shall be identified at 
terminal and junction locations in a manner that will prevent 
unintentional interference with the signaling circuit during testing 
and servicing. Power-limited fire alarm circuits shall be durably 
marked as such where plainly visible at terminations.
    (e) Communications systems. This paragraph applies to central-
station-connected and non-central-station-connected telephone circuits, 
radio and television receiving and transmitting equipment, including 
community antenna television and radio distribution systems, telegraph, 
district messenger, and outside wiring for fire and burglar alarm, and 
similar central station systems. These installations need not comply 
with the provisions of Sec.  1910.303 through Sec.  1910.308(d), except 
for Sec.  1910.304(c)(1) and Sec.  1910.307.
    (1) Protective devices. (i) A listed primary protector shall be 
provided on each circuit run partly or entirely in aerial wire or 
aerial cable not confined within a block.
    (ii) A listed primary protector shall be also provided on each 
circuit, aerial or underground, located within the block containing the 
building served so as to be exposed to accidental contact with electric 
light or power conductors operating at over 300 volts to ground.
    (iii) In addition, where there exists a lightning exposure, each 
interbuilding circuit on premises shall be protected by a listed 
primary protector at each end of the interbuilding circuit.
    (2) Conductor location. (i) Lead-in or aerial-drop cables from a 
pole or other support, including the point of initial attachment to a 
building or structure, shall be kept away from electric light, power, 
Class 1, or nonpower-limited fire alarm circuit conductors so as to 
avoid the possibility of accidental contact.
    (ii) A separation of at least 1.83 m (6 ft) shall be maintained 
between communications wires and cables on buildings and lightning 
conductors.
    (iii) Where communications wires and cables and electric light or 
power conductors are supported by the same pole or run parallel to each 
other in-span, the following conditions shall be met:
    (A) Where practicable, communication wires and cables on poles 
shall be located below the electric light or power conductors.
    (B) Communications wires and cables may not be attached to a 
crossarm that carries electric light or power conductors.
    (iv) Indoor communications wires and cables shall be separated at 
least 50.8 mm (2 in.) from conductors of any electric light, power, 
Class 1, nonpower-limited fire alarm, or medium power network-powered 
broadband communications circuits, unless a special and equally 
protective method of conductor separation, identified for the purpose, 
is employed.
    (3) Equipment location. Outdoor metal structures supporting 
antennas, as well as self-supporting antennas such as vertical rods or 
dipole structures, shall be located as far away from overhead 
conductors of electric light and power circuits of over 150 volts to 
ground as necessary to prevent the antenna or structure from falling 
into or making accidental contact with such circuits.
    (4) Grounding. (i) If exposed to contact with electric light and 
power conductors, the metal sheath of aerial cables entering buildings 
shall be grounded or shall be interrupted close to the entrance to the 
building by an insulating joint or equivalent device. Where protective 
devices are used, they shall be grounded in an approved manner.
    (ii) Masts and metal structures supporting antennas shall be 
permanently and effectively grounded without splice or connection in 
the grounding conductor.
    (iii) Transmitters shall be enclosed in a metal frame or grill or 
separated from the operating space by a barrier, all metallic parts of 
which are effectively connected to ground. All external metal handles 
and controls accessible to the operating personnel shall be effectively 
grounded. Unpowered equipment and enclosures are considered to be 
grounded where connected to an attached coaxial cable with an 
effectively grounded metallic shield.
    (f) Solar photovoltaic systems. This paragraph covers solar 
photovoltaic systems that can be interactive with other electric power 
production sources or can stand alone with or without electrical energy 
storage such as batteries. These systems may have ac or dc output for 
utilization.
    (1) Conductors of different systems. Photovoltaic source circuits 
and photovoltaic output circuits may not be contained in the same 
raceway, cable tray, cable, outlet box, junction box, or similar 
fitting as feeders or branch circuits of other systems, unless the 
conductors of the different systems are separated by a partition or are 
connected together.
    (2) Disconnecting means. Means shall be provided to disconnect all 
current-carrying conductors of a photovoltaic power source from all 
other conductors in a building or other structure. Where a circuit 
grounding connection is not designed to be automatically interrupted as 
part of the ground-fault protection system, a switch or circuit breaker 
used as disconnecting means may not have a pole in the grounded 
conductor.
    (g) Integrated electrical systems--(1) Scope. Paragraph (g) of this 
section covers integrated electrical systems, other than unit 
equipment, in which orderly shutdown is necessary to ensure safe 
operation. An integrated electrical system as used in this section 
shall be a unitized segment of an industrial wiring system where all of 
the following conditions are met:
    (i) An orderly shutdown process minimizes employee hazard and 
equipment damage;
    (ii) The conditions of maintenance and supervision ensure that only 
qualified persons will service the system; and
    (iii) Effective safeguards are established and maintained.
    (2) Location of overcurrent devices in or on premises. Overcurrent 
devices that are critical to integrated electrical systems need not be 
readily accessible to employees as required by Sec.  1910.304(f)(1)(iv) 
if they are located with mounting heights to ensure security from 
operation by nonqualified persons.
    5. Section 1910.399 would be revised to read as follows:


Sec.  1910.399  Definitions applicable to this subpart.

    Acceptable. An installation or equipment is acceptable to the 
Assistant Secretary of Labor, and approved within the meaning of this 
Subpart S:
    (1) If it is accepted, or certified, or listed, or labeled, or 
otherwise determined to be safe by a nationally recognized testing 
laboratory recognized pursuant to Sec.  1910.7; or
    (2) With respect to an installation or equipment of a kind that no 
nationally recognized testing laboratory accepts, certifies, lists, 
labels, or determines to be safe, if it is inspected or tested by 
another Federal agency, or by a State, municipal, or other local 
authority responsible for enforcing occupational safety provisions of 
the National

[[Page 17836]]

Electrical Code, and found in compliance with the provisions of the 
National Electrical Code as applied in this subpart; or
    (3) With respect to custom-made equipment or related installations 
that are designed, fabricated for, and intended for use by a particular 
customer, if it is determined to be safe for its intended use by its 
manufacturer on the basis of test data which the employer keeps and 
makes available for inspection to the Assistant Secretary and his 
authorized representatives.
    Accepted. An installation is ``accepted'' if it has been inspected 
and found by a nationally recognized testing laboratory to conform to 
specified plans or to procedures of applicable codes.
    Accessible. (As applied to wiring methods.) Capable of being 
removed or exposed without damaging the building structure or finish, 
or not permanently closed in by the structure or finish of the 
building. (See ``concealed'' and ``exposed.'')
    Accessible. (As applied to equipment.) Admitting close approach; 
not guarded by locked doors, elevation, or other effective means. (See 
``Readily accessible.'')
    Ampacity. The current, in amperes, that a conductor can carry 
continuously under the conditions of use without exceeding its 
temperature rating.
    Appliances. Utilization equipment, generally other than industrial, 
normally built in standardized sizes or types, that is installed or 
connected as a unit to perform one or more functions.
    Approved. Acceptable to the authority enforcing this subpart. The 
authority enforcing this subpart is the Assistant Secretary of Labor 
for Occupational Safety and Health. The definition of ``acceptable'' 
indicates what is acceptable to the Assistant Secretary of Labor, and 
therefore approved within the meaning of this subpart.
    Armored cable. Type AC armored cable is a fabricated assembly of 
insulated conductors in a flexible metallic enclosure.
    Askarel. A generic term for a group of nonflammable synthetic 
chlorinated hydrocarbons used as electrical insulating media. Askarels 
of various compositional types are used. Under arcing conditions the 
gases produced, while consisting predominantly of noncombustible 
hydrogen chloride, can include varying amounts of combustible gases 
depending upon the askarel type.
    Attachment plug (Plug cap)(Cap). A device that, by insertion in a 
receptacle, establishes a connection between the conductors of the 
attached flexible cord and the conductors connected permanently to the 
receptacle.
    Automatic. Self-acting, operating by its own mechanism when 
actuated by some impersonal influence, as, for example, a change in 
current strength, pressure, temperature, or mechanical configuration.
    Bare conductor. See Conductor.
    Barrier. A physical obstruction that is intended to prevent contact 
with equipment or live parts or to prevent unauthorized access to a 
work area.
    Bathroom. An area including a basin with one or more of the 
following: a toilet, a tub, or a shower.
    Bonding (Bonded). The permanent joining of metallic parts to form 
an electrically conductive path that will ensure electrical continuity 
and the capacity to conduct safely any current likely to be imposed.
    Bonding jumper. A conductor that assures the necessary electrical 
conductivity between metal parts required to be electrically connected.
    Branch circuit. The circuit conductors between the final 
overcurrent device protecting the circuit and the outlets.
    Building. A structure that stands alone or is cut off from 
adjoining structures by fire walls with all openings therein protected 
by approved fire doors.
    Cabinet. An enclosure designed either for surface or flush 
mounting, and provided with a frame, mat, or trim in which a swinging 
door or doors are or can be hung.
    Cable tray system. A unit or assembly of units or sections, and 
associated fittings forming a rigid structural system used to securely 
fasten or support cables and raceways. Cable tray systems include 
ladders, troughs, channels, solid bottom trays, and other similar 
structures.
    Cablebus. An assembly of insulated conductors with fittings and 
conductor terminations in a completely enclosed, ventilated, protective 
metal housing.
    Cell line. An assembly of electrically interconnected electrolytic 
cells supplied by a source of direct current power.
    Cell line attachments and auxiliary equipment. Cell line 
attachments and auxiliary equipment include, but are not limited to, 
auxiliary tanks, process piping, ductwork, structural supports, exposed 
cell line conductors, conduits and other raceways, pumps, positioning 
equipment, and cell cutout or bypass electrical devices. Auxiliary 
equipment also includes tools, welding machines, crucibles, and other 
portable equipment used for operation and maintenance within the 
electrolytic cell line working zone. In the cell line working zone, 
auxiliary equipment includes the exposed conductive surfaces of 
ungrounded cranes and crane-mounted cell-servicing equipment.
    Center pivot irrigation machine. A multi-motored irrigation machine 
that revolves around a central pivot and employs alignment switches or 
similar devices to control individual motors.
    Certified. Equipment is ``certified'' if it bears a label, tag, or 
other record of certification that the equipment: (1) has been tested 
and found by a nationally recognized testing laboratory to meet 
nationally recognized standards or to be safe for use in a specified 
manner, or (2) is of a kind whose production is periodically inspected 
by a nationally recognized testing laboratory and is accepted by the 
laboratory as safe for its intended use.
    Circuit breaker. A device designed to open and close a circuit by 
nonautomatic means and to open the circuit automatically on a 
predetermined overcurrent without damage to itself when properly 
applied within its rating.
    Class I locations. Class I locations are those in which flammable 
gases or vapors are or may be present in the air in quantities 
sufficient to produce explosive or ignitable mixtures. Class I 
locations include the following:
    (1) Class I, Division 1. A Class I, Division 1 location is a 
location: (i) In which ignitable concentrations of flammable gases or 
vapors may exist under normal operating conditions; or (ii) in which 
ignitable concentrations of such gases or vapors may exist frequently 
because of repair or maintenance operations or because of leakage; or 
(iii) in which breakdown or faulty operation of equipment or processes 
might release ignitable concentrations of flammable gases or vapors, 
and might also cause simultaneous failure of electric equipment.

    Note to the definition of ``Class I, Division 1:'' This 
classification usually includes locations where volatile flammable 
liquids or liquefied flammable gases are transferred from one 
container to another; interiors of spray booths and areas in the 
vicinity of spraying and painting operations where volatile 
flammable solvents are used; locations containing open tanks or vats 
of volatile flammable liquids; drying rooms or compartments for the 
evaporation of flammable solvents; locations containing fat and oil 
extraction equipment using volatile flammable solvents; portions of 
cleaning and dyeing plants where flammable liquids are used; gas 
generator rooms and other portions of gas manufacturing plants where 
flammable gas may escape; inadequately ventilated pump rooms for 
flammable gas or for volatile flammable liquids; the interiors of 
refrigerators and freezers in which volatile flammable materials are 
stored in open,

[[Page 17837]]

lightly stoppered, or easily ruptured containers; and all other 
locations where ignitable concentrations of flammable vapors or 
gases are likely to occur in the course of normal operations.

    (2) Class I, Division 2. A Class I, Division 2 location is a 
location: (i) In which volatile flammable liquids or flammable gases 
are handled, processed, or used, but in which the hazardous liquids, 
vapors, or gases will normally be confined within closed containers or 
closed systems from which they can escape only in the event of 
accidental rupture or breakdown of such containers or systems, or as a 
result of abnormal operation of equipment; or (ii) in which ignitable 
concentrations of gases or vapors are normally prevented by positive 
mechanical ventilation, and which might become hazardous through 
failure or abnormal operations of the ventilating equipment; or (iii) 
that is adjacent to a Class I, Division 1 location, and to which 
ignitable concentrations of gases or vapors might occasionally be 
communicated unless such communication is prevented by adequate 
positive-pressure ventilation from a source of clean air, and effective 
safeguards against ventilation failure are provided.

    Note to the definition of ``Class I, Division 2:'' This 
classification usually includes locations where volatile flammable 
liquids or flammable gases or vapors are used, but which would 
become hazardous only in case of an accident or of some unusual 
operating condition. The quantity of flammable material that might 
escape in case of accident, the adequacy of ventilating equipment, 
the total area involved, and the record of the industry or business 
with respect to explosions or fires are all factors that merit 
consideration in determining the classification and extent of each 
location.
    Piping without valves, checks, meters, and similar devices would 
not ordinarily introduce a hazardous condition even though used for 
flammable liquids or gases. Locations used for the storage of 
flammable liquids or a liquefied or compressed gases in sealed 
containers would not normally be considered hazardous unless also 
subject to other hazardous conditions.
    Electrical conduits and their associated enclosures separated 
from process fluids by a single seal or barrier are classed as a 
Division 2 location if the outside of the conduit and enclosures is 
a nonhazardous location.

    (3) Class I, Zone 0. A Class I, Zone 0 location is a location in 
which one of the following conditions exists:
    (i) Ignitable concentrations of flammable gases or vapors are 
present continuously, or
    (ii) Ignitable concentrations of flammable gases or vapors are 
present for long periods of time.

    Note to the definition of ``Class I, Zone 0:'' As a guide in 
determining when flammable gases or vapors are present continuously 
or for long periods of time, refer to Recommended Practice for 
Classification of Locations for Electrical Installations of 
Petroleum Facilities Classified as Class I, Zone 0, Zone 1 or Zone 
2, API RP 505-1996; Electrical Apparatus for Explosive Gas 
Atmospheres, Classifications of Hazardous Areas, IEC 79-10-1995; 
Area Classification Code for Petroleum Installations, Model Code--
Part 15, Institute for Petroleum; and Electrical Apparatus for 
Explosive Gas Atmospheres, Classifications of Hazardous (Classified) 
Locations, ISA S12.24.01-1997.

    (4) Class I, Zone 1. A Class I, Zone 1 location is a location in 
which one of the following conditions exists:
    (i) Ignitable concentrations of flammable gases or vapors are 
likely to exist under normal operating conditions; or
    (ii) Ignitable concentrations of flammable gases or vapors may 
exist frequently because of repair or maintenance operations or because 
of leakage; or
    (iii) Equipment is operated or processes are carried on of such a 
nature that equipment breakdown or faulty operations could result in 
the release of ignitable concentrations of flammable gases or vapors 
and also cause simultaneous failure of electric equipment in a manner 
that would cause the electric equipment to become a source of ignition; 
or
    (iv) A location that is adjacent to a Class I, Zone 0 location from 
which ignitable concentrations of vapors could be communicated, unless 
communication is prevented by adequate positive pressure ventilation 
from a source of clean air and effective safeguards against ventilation 
failure are provided.
    (5) Class I, Zone 2. A Class I, Zone 2 location is a location in 
which one of the following conditions exists:
    (i) Ignitable concentrations of flammable gases or vapors are not 
likely to occur in normal operation and if they do occur will exist 
only for a short period; or
    (ii) Volatile flammable liquids, flammable gases, or flammable 
vapors are handled, processed, or used, but in which the liquids, 
gases, or vapors are normally confined within closed containers or 
closed systems from which they can escape only as a result of 
accidental rupture or breakdown of the containers or system or as the 
result of the abnormal operation of the equipment with which the 
liquids or gases are handled, processed, or used; or
    (iii) Ignitable concentrations of flammable gases or vapors 
normally are prevented by positive mechanical ventilation, but which 
may become hazardous as the result of failure or abnormal operation of 
the ventilation equipment; or
    (iv) A location that is adjacent to a Class I, Zone 1 location, 
from which ignitable concentrations of flammable gases or vapors could 
be communicated, unless such communication is prevented by adequate 
positive-pressure ventilation from a source of clean air, and effective 
safeguards against ventilation failure are provided.
    Class II locations. Class II locations are those that are hazardous 
because of the presence of combustible dust. Class II locations include 
the following:
    (1) Class II, Division 1. A Class II, Division 1 location is a 
location: (i) In which combustible dust is or may be in suspension in 
the air under normal operating conditions, in quantities sufficient to 
produce explosive or ignitable mixtures; or (ii) where mechanical 
failure or abnormal operation of machinery or equipment might cause 
such explosive or ignitable mixtures to be produced, and might also 
provide a source of ignition through simultaneous failure of electric 
equipment, through operation of protection devices, or from other 
causes; or (iii) in which combustible dusts of an electrically 
conductive nature may be present.

    Note to the definition of ``Class II, Division 1'': This 
classification may include areas of grain handling and processing 
plants, starch plants, sugar-pulverizing plants, malting plants, 
hay-grinding plants, coal pulverizing plants, areas where metal 
dusts and powders are produced or processed, and other similar 
locations that contain dust producing machinery and equipment 
(except where the equipment is dust-tight or vented to the outside). 
These areas would have combustible dust in the air, under normal 
operating conditions, in quantities sufficient to produce explosive 
or ignitable mixtures. Combustible dusts that are electrically 
nonconductive include dusts produced in the handling and processing 
of grain and grain products, pulverized sugar and cocoa, dried egg 
and milk powders, pulverized spices, starch and pastes, potato and 
wood flour, oil meal from beans and seed, dried hay, and other 
organic materials which may produce combustible dusts when processed 
or handled. Dusts containing magnesium or aluminum are particularly 
hazardous, and the use of extreme caution is necessary to avoid 
ignition and explosion.

    (2) Class II, Division 2. A Class II, Division 2 location is a 
location where: (i) Combustible dust will not normally be in suspension 
in the air in quantities sufficient to produce explosive or ignitable 
mixtures, and dust accumulations will normally be insufficient to 
interfere with the normal operation of electric equipment or other

[[Page 17838]]

apparatus, but combustible dust may be in suspension in the air as a 
result of infrequent malfunctioning of handling or processing 
equipment, and (ii) resulting combustible dust accumulations on, in, or 
in the vicinity of the electric equipment may be sufficient to 
interfere with the safe dissipation of heat from electric equipment or 
may be ignitable by abnormal operation or failure of electric 
equipment.

    Note to the definition of ``Class II, Division 2'':  This 
classification includes locations where dangerous concentrations of 
suspended dust would not be likely, but where dust accumulations 
might form on or in the vicinity of electric equipment. These areas 
may contain equipment from which appreciable quantities of dust 
would escape under abnormal operating conditions or be adjacent to a 
Class II Division 1 location, as described above, into which an 
explosive or ignitable concentration of dust may be put into 
suspension under abnormal operating conditions.

    Class III locations. Class III locations are those that are 
hazardous because of the presence of easily ignitable fibers or 
flyings, but in which such fibers or flyings are not likely to be in 
suspension in the air in quantities sufficient to produce ignitable 
mixtures. Class III locations include the following:
    (1) Class III, Division 1. A Class III, Division 1 location is a 
location in which easily ignitable fibers or materials producing 
combustible flyings are handled, manufactured, or used.

    Note to the definition of ``Class III, Division 1'':  Such 
locations usually include some parts of rayon, cotton, and other 
textile mills; combustible fiber manufacturing and processing 
plants; cotton gins and cotton-seed mills; flax-processing plants; 
clothing manufacturing plants; woodworking plants, and 
establishments; and industries involving similar hazardous processes 
or conditions.
    Easily ignitable fibers and flyings include rayon, cotton 
(including cotton linters and cotton waste), sisal or henequen, 
istle, jute, hemp, tow, cocoa fiber, oakum, baled waste kapok, 
Spanish moss, excelsior, and other materials of similar nature.

    (2) Class III, Division 2. A Class III, Division 2 location is a 
location in which easily ignitable fibers are stored or handled, other 
than in the process of manufacture.
    Collector ring. An assembly of slip rings for transferring electric 
energy from a stationary to a rotating member.
    Concealed. Rendered inaccessible by the structure or finish of the 
building. Wires in concealed raceways are considered concealed, even 
though they may become accessible by withdrawing them. (See Accessible. 
(As applied to wiring methods.))
    Conductor--(1) Bare. A conductor having no covering or electrical 
insulation whatsoever.
    (2) Covered. A conductor encased within material of composition or 
thickness that is not recognized by this subpart as electrical 
insulation.
    (3) Insulated. A conductor encased within material of composition 
and thickness that is recognized by this subpart as electrical 
insulation.
    Conduit body. A separate portion of a conduit or tubing system that 
provides access through one or more removable covers to the interior of 
the system at a junction of two or more sections of the system or at a 
terminal point of the system. Boxes such as FS and FD or larger cast or 
sheet metal boxes are not classified as conduit bodies.
    Controller. A device or group of devices that serves to govern, in 
some predetermined manner, the electric power delivered to the 
apparatus to which it is connected.
    Covered conductor. See Conductor.
    Cutout. (Over 600 volts, nominal.) An assembly of a fuse support 
with either a fuseholder, fuse carrier, or disconnecting blade. The 
fuseholder or fuse carrier may include a conducting element (fuse 
link), or may act as the disconnecting blade by the inclusion of a 
nonfusible member.
    Cutout box. An enclosure designed for surface mounting and having 
swinging doors or covers secured directly to and telescoping with the 
walls of the box proper. (See Cabinet.)
    Damp location. See Location.
    Dead front. Without live parts exposed to a person on the operating 
side of the equipment
    Deenergized. Free from any electrical connection to a source of 
potential difference and from electrical charge; not having a potential 
different from that of the earth.
    Device. A unit of an electrical system that is intended to carry 
but not utilize electric energy.
    Dielectric heating. The heating of a nominally insulating material 
due to its own dielectric losses when the material is placed in a 
varying electric field.
    Disconnecting means. A device, or group of devices, or other means 
by which the conductors of a circuit can be disconnected from their 
source of supply.
    Disconnecting (or Isolating) switch. (Over 600 volts, nominal.) A 
mechanical switching device used for isolating a circuit or equipment 
from a source of power.
    Electrolytic cell line working zone. The cell line working zone is 
the space envelope wherein operation or maintenance is normally 
performed on or in the vicinity of exposed energized surfaces of 
electrolytic cell lines or their attachments.
    Electrolytic cells. A tank or vat in which electrochemical 
reactions are caused by applying energy for the purpose of refining or 
producing usable materials.
    Enclosed. Surrounded by a case, housing, fence or walls that will 
prevent persons from accidentally contacting energized parts.
    Enclosure. The case or housing of apparatus, or the fence or walls 
surrounding an installation to prevent personnel from accidentally 
contacting energized parts, or to protect the equipment from physical 
damage.
    Energized. Electrically connected to a source of potential 
difference.
    Equipment. A general term including material, fittings, devices, 
appliances, fixtures, apparatus, and the like, used as a part of, or in 
connection with, an electrical installation.
    Equipment grounding conductor. See Grounding conductor, equipment.
    Explosion-proof apparatus. Apparatus enclosed in a case that is 
capable of withstanding an explosion of a specified gas or vapor that 
may occur within it and of preventing the ignition of a specified gas 
or vapor surrounding the enclosure by sparks, flashes, or explosion of 
the gas or vapor within, and that operates at such an external 
temperature that it will not ignite a surrounding flammable atmosphere.
    Exposed. (As applied to live parts.) Capable of being inadvertently 
touched or approached nearer than a safe distance by a person. It is 
applied to parts not suitably guarded, isolated, or insulated. (See 
Accessible and Concealed.)
    Exposed. (As applied to wiring methods.) On or attached to the 
surface, or behind panels designed to allow access. (See Accessible. 
(As applied to wiring methods.))
    Exposed. (For the purposes of Sec.  1910.308(e).) Where the circuit 
is in such a position that in case of failure of supports or 
insulation, contact with another circuit may result.
    Externally operable. Capable of being operated without exposing the 
operator to contact with live parts.
    Feeder. All circuit conductors between the service equipment, the 
source of a separate derived system, or other power supply source and 
the final branch-circuit overcurrent device.
    Fitting. An accessory such as a locknut, bushing, or other part of 
a wiring system that is intended primarily to perform a mechanical 
rather than an electrical function.

[[Page 17839]]

    Fuse. (Over 600 volts, nominal.) An overcurrent protective device 
with a circuit opening fusible part that is heated and severed by the 
passage of overcurrent through it. A fuse comprises all the parts that 
form a unit capable of performing the prescribed functions. It may or 
may not be the complete device necessary to connect it into an 
electrical circuit.
    Ground. A conducting connection, whether intentional or accidental, 
between an electric circuit or equipment and the earth, or to some 
conducting body that serves in place of the earth.
    Grounded. Connected to the earth or to some conducting body that 
serves in place of the earth.
    Grounded, effectively. (Over 600 volts, nominal.) Permanently 
connected to earth through a ground connection of sufficiently low 
impedance and having sufficient ampacity that ground fault current that 
may occur cannot build up to voltages dangerous to personnel.
    Grounded conductor. A system or circuit conductor that is 
intentionally grounded.
    Grounding conductor. A conductor used to connect equipment or the 
grounded circuit of a wiring system to a grounding electrode or 
electrodes.
    Grounding conductor, equipment. The conductor used to connect the 
noncurrent-carrying metal parts of equipment, raceways, and other 
enclosures to the system grounded conductor, the grounding electrode 
conductor, or both, at the service equipment or at the source of a 
separately derived system.
    Grounding electrode conductor. The conductor used to connect the 
grounding electrode to the equipment grounding conductor, to the 
grounded conductor, or to both, of the circuit at the service equipment 
or at the source of a separately derived system.
    Ground-fault circuit-interrupter. A device intended for the 
protection of personnel that functions to deenergize a circuit or a 
portion of a circuit within an established period of time when a 
current to ground exceeds some predetermined value that is less than 
that required to operate the overcurrent protective device of the 
supply circuit.
    Guarded. Covered, shielded, fenced, enclosed, or otherwise 
protected by means of suitable covers, casings, barriers, rails, 
screens, mats, or platforms to remove the likelihood of approach to a 
point of danger or contact by persons or objects.
    Health care facilities. Buildings or portions of buildings and 
mobile homes that contain, but are not limited to, hospitals, nursing 
homes, extended care facilities, clinics, and medical and dental 
offices, whether fixed or mobile.
    Heating equipment. For the purposes of Sec.  1910.306(g), the term 
``heating equipment'' includes any equipment used for heating purposes 
if heat is generated by induction or dielectric methods.
    Hoistway. Any shaftway, hatchway, well hole, or other vertical 
opening or space that is designed for the operation of an elevator or 
dumbwaiter.
    Identified (as applied to equipment). Approved as suitable for the 
specific purpose, function, use, environment, or application, where 
described in a particular requirement.

    Note to the definition of ``identified'':  Some examples of ways 
to determine suitability of equipment for a specific purpose, 
environment, or application include investigations by a nationally 
recognized testing laboratory (through listing and labeling), and 
inspection agency, or other organization recognized under the 
definition of ``acceptable.''

    Induction heating. The heating of a nominally conductive material 
due to its own I2R losses when the material is placed in a 
varying electromagnetic field.
    Insulated. Separated from other conducting surfaces by a dielectric 
(including air space) offering a high resistance to the passage of 
current.
    Insulated conductor. See Conductor, Insulated.
    Interrupter switch. (Over 600 volts, nominal.) A switch capable of 
making, carrying, and interrupting specified currents.
    Irrigation Machine. An electrically driven or controlled machine, 
with one or more motors, not hand portable, and used primarily to 
transport and distribute water for agricultural purposes.
    Isolated. (As applied to location.) Not readily accessible to 
persons unless special means for access are used.
    Isolated power system. A system comprising an isolating transformer 
or its equivalent, a line isolation monitor, and its ungrounded circuit 
conductors.
    Labeled. Equipment is ``labeled'' if there is attached to it a 
label, symbol, or other identifying mark of a nationally recognized 
testing laboratory:
    (1) That makes periodic inspections of the production of such 
equipment, and
    (2) Whose labeling indicates compliance with nationally recognized 
standards or tests to determine safe use in a specified manner.
    Lighting outlet. An outlet intended for the direct connection of a 
lampholder, a lighting fixture, or a pendant cord terminating in a 
lampholder.
    Line-clearance tree trimming. The pruning, trimming, repairing, 
maintaining, removing, or clearing of trees or cutting of brush that is 
within 305 cm (10 ft) of electric supply lines and equipment.
    Listed. Equipment is ``listed'' if it is of a kind mentioned in a 
list that:
    (1) Is published by a nationally recognized laboratory that makes 
periodic inspection of the production of such equipment, and
    (2) States that such equipment meets nationally recognized 
standards or has been tested and found safe for use in a specified 
manner.
    Live parts. Electric conductors, buses, terminals, or components 
that are energized.
    Location--(1) Damp location. Partially protected locations under 
canopies, marquees, roofed open porches, and like locations, and 
interior locations subject to moderate degrees of moisture, such as 
some basements, some barns, and some cold-storage warehouses.
    (2) Dry location. A location not normally subject to dampness or 
wetness. A location classified as dry may be temporarily subject to 
dampness or wetness, as in the case of a building under construction.
    (3) Wet location. Installations underground or in concrete slabs or 
masonry in direct contact with the earth, and locations subject to 
saturation with water or other liquids, such as vehicle-washing areas, 
and locations unprotected and exposed to weather.
    Medium voltage cable. Type MV cable is a single or multiconductor 
solid dielectric insulated cable rated 2001 volts or higher.
    Metal-clad cable. Type MC cable is a factory assembly of one or 
more insulated circuit conductors with or without optical fiber members 
enclosed in an armor of interlocking metal tape, or a smooth or 
corrugated metallic sheath.
    Mineral-insulated metal-sheathed cable. Type MI, mineral-insulated 
metal-sheathed, cable is a factory assembly of one or more conductors 
insulated with a highly compressed refractory mineral insulation and 
enclosed in a liquidtight and gastight continuous copper sheath.
    Mobile X-ray. X-ray equipment mounted on a permanent base with 
wheels or casters or both for moving while completely assembled.
    Motor control center. An assembly of one or more enclosed sections 
having a common power bus and principally containing motor control 
units.
    Nonmetallic-sheathed cable. Nonmetallic-sheathed cable is a factory 
assembly of two or more insulated conductors having an outer sheath of

[[Page 17840]]

moisture resistant, flame-retardant, nonmetallic material. Nonmetallic 
sheathed cable is manufactured in the following types:
    (1) Type NM. The overall covering has a flame-retardant and 
moisture-resistant finish.
    (2) Type NMC. The overall covering is flame-retardant, moisture-
resistant, fungus-resistant, and corrosion-resistant.
    Oil (filled) cutout. (Over 600 volts, nominal.) A cutout in which 
all or part of the fuse support and its fuse link or disconnecting 
blade are mounted in oil with complete immersion of the contacts and 
the fusible portion of the conducting element (fuse link), so that arc 
interruption by severing of the fuse link or by opening of the contacts 
will occur under oil.
    Open wiring on insulators. Open wiring on insulators is an exposed 
wiring method using cleats, knobs, tubes, and flexible tubing for the 
protection and support of single insulated conductors run in or on 
buildings, and not concealed by the building structure.
    Outlet. A point on the wiring system at which current is taken to 
supply utilization equipment.
    Outline lighting. An arrangement of incandescent lamps or electric 
discharge lighting to outline or call attention to certain features, 
such as the shape of a building or the decoration of a window.
    Overcurrent. Any current in excess of the rated current of 
equipment or the ampacity of a conductor. It may result from overload, 
short circuit, or ground fault.
    Overhaul means to perform a major replacement, modification, 
repair, or rehabilitation similar to that involved when a new building 
or facility is built, a new wing is added, or an entire floor is 
renovated.
    Overload. Operation of equipment in excess of normal, full-load 
rating, or of a conductor in excess of rated ampacity that, when it 
persists for a sufficient length of time, would cause damage or 
dangerous overheating. A fault, such as a short circuit or ground 
fault, is not an overload. (See Overcurrent.)
    Panelboard. A single panel or group of panel units designed for 
assembly in the form of a single panel; including buses, automatic 
overcurrent devices, and with or without switches for the control of 
light, heat, or power circuits; designed to be placed in a cabinet or 
cutout box placed in or against a wall or partition and accessible only 
from the front. (See Switchboard.)
    Permanently installed decorative fountains and reflection pools. 
Pools that are constructed in the ground, on the ground, or in a 
building in such a manner that the fountain or pool cannot be readily 
disassembled for storage, whether or not served by electrical circuits 
of any nature. These units are primarily constructed for their 
aesthetic value and are not intended for swimming or wading.
    Permanently installed swimming, wading, and therapeutic pools. 
Pools that are constructed in the ground or partially in the ground, 
and all other capable of holding water in a depth greater than 1.07 m 
(42 in.). The definition also applies to all pools installed inside of 
a building, regardless of water depth, whether or not served by 
electric circuits of any nature.
    Portable X-ray. X-ray equipment designed to be hand-carried.
    Power and control tray cable. Type TC power and control tray cable 
is a factory assembly of two or more insulated conductors, with or 
without associated bare or covered grounding conductors under a 
nonmetallic sheath, approved for installation in cable trays, in 
raceways, or where supported by a messenger wire.
    Power fuse. (Over 600 volts, nominal.) See Fuse.
    Power-limited tray cable. Type PLTC nonmetallic-sheathed power 
limited tray cable is a factory assembly of two or more insulated 
conductors under a nonmetallic jacket.
    Power outlet. An enclosed assembly, which may include receptacles, 
circuit breakers, fuseholders, fused switches, buses, and watt-hour 
meter mounting means, that is intended to supply and control power to 
mobile homes, recreational vehicles, or boats or to serve as a means 
for distributing power needed to operate mobile or temporarily 
installed equipment.
    Premises wiring. (Premises wiring system.) That interior and 
exterior wiring, including power, lighting, control, and signal circuit 
wiring together with all of their associated hardware, fittings, and 
wiring devices, both permanently and temporarily installed, that 
extends from the service point of utility conductors or source of power 
such as a battery, a solar photovoltaic system, or a generator, 
transformer, or converter to the outlets. Such wiring does not include 
wiring internal to appliances, fixtures, motors, controllers, motor 
control centers, and similar equipment.
    Qualified person. A person who is familiar with the construction 
and operation of the equipment and the hazards involved.

    Note 1 to the definition of ``qualified person:'' Whether an 
employee is considered to be a ``qualified person'' will depend upon 
various circumstances in the workplace. It is possible and, in fact, 
likely for an individual to be considered ``qualified'' with regard 
to certain equipment in the workplace, but ``unqualified'' as to 
other equipment.(See 1910.332(b)(3) for training requirements that 
specifically apply to qualified persons.)


    Note 2 to the definition of ``qualified person:'' An employee 
who is undergoing on-the-job training and who, in the course of such 
training, has demonstrated an ability to perform duties safely at 
his or her level of training and who is under the direct supervision 
of a qualified person is considered to be a qualified person for the 
performance of those duties.

    Raceway. An enclosed channel of metal or nonmetallic materials 
designed expressly for holding wires, cables, or busbars, with 
additional functions as permitted in this standard. Raceways include, 
but are not limited to, rigid metal conduit, rigid nonmetallic conduit, 
intermediate metal conduit, liquidtight flexible conduit, flexible 
metallic tubing, flexible metal conduit, electrical metallic tubing, 
electrical nonmetallic tubing, underfloor raceways, cellular concrete 
floor raceways, cellular metal floor raceways, surface raceways, 
wireways, and busways.
    Readily accessible. Capable of being reached quickly for operation, 
renewal, or inspections, so that those needing ready access do not have 
to climb over or remove obstacles or to resort to portable ladders, 
chairs, etc. (See Accessible.)
    Receptacle. A receptacle is a contact device installed at the 
outlet for the connection of an attachment plug. A single receptacle is 
a single contact device with no other contact device on the same yoke. 
A multiple receptacle is two or more contact devices on the same yoke.
    Receptacle outlet. An outlet where one or more receptacles are 
installed.
    Remote-control circuit. Any electric circuit that controls any 
other circuit through a relay or an equivalent device.
    Sealable equipment. Equipment enclosed in a case or cabinet that is 
provided with a means of sealing or locking so that live parts cannot 
be made accessible without opening the enclosure. The equipment may or 
may not be operable without opening the enclosure.
    Separately derived system. A premises wiring system whose power is 
derived from a battery, a solar photovoltaic system, or from a 
generator, transformer, or converter windings, and that has no direct 
electrical connection, including a solidly connected grounded circuit

[[Page 17841]]

conductor, to supply conductors originating in another system.
    Service. The conductors and equipment for delivering electric 
energy from the serving utility to the wiring system of the premises 
served.
    Service cable. Service conductors made up in the form of a cable.
    Service conductors. The conductors from the service point to the 
service disconnecting means.
    Service drop. The overhead service conductors from the last pole or 
other aerial support to and including the splices, if any, connecting 
to the service-entrance conductors at the building or other structure.
    Service-entrance cable. Service-entrance cable is a single 
conductor or multiconductor assembly provided with or without an 
overall covering, primarily used for services, and is of the following 
types:
    (1) Type SE. Type SE, having a flame-retardant, moisture resistant 
covering
    (2) Type USE. Type USE, identified for underground use, having a 
moisture-resistant covering, but not required to have a flame-retardant 
covering. Cabled, single-conductor, Type USE constructions recognized 
for underground use may have a bare copper conductor cabled with the 
assembly. Type USE single, parallel, or cable conductor assemblies 
recognized for underground use may have a bare copper concentric 
conductor applied. These constructions do not require an outer overall 
covering.
    Service-entrance conductors, overhead system. The service 
conductors between the terminals of the service equipment and a point 
usually outside the building, clear of building walls, where joined by 
tape or splice to the service drop.
    Service entrance conductors, underground system. The service 
conductors between the terminals of the service equipment and the point 
of connection to the service lateral.
    Service equipment. The necessary equipment, usually consisting of 
one or more circuit breakers or switches and fuses, and their 
accessories, connected to the load end of service conductors to a 
building or other structure, or an otherwise designated area, and 
intended to constitute the main control and cutoff of the supply.
    Service point. The point of connection between the facilities of 
the serving utility and the premises wiring.
    Shielded nonmetallic-sheathed cable. Type SNM, shielded 
nonmetallic-sheathed cable is a factory assembly of two or more 
insulated conductors in an extruded core of moisture-resistant, flame-
resistant nonmetallic material, covered with an overlapping spiral 
metal tape and wire shield and jacketed with an extruded moisture-, 
flame-, oil-, corrosion-, fungus-, and sunlight-resistant nonmetallic 
material.
    Show window. Any window used or designed to be used for the display 
of goods or advertising material, whether it is fully or partly 
enclosed or entirely open at the rear and whether or not it has a 
platform raised higher than the street floor level.
    Signaling circuit. Any electric circuit that energizes signaling 
equipment.
    Storable swimming or wading pool. A pool that is constructed on or 
above the ground and is capable of holding water to a maximum depth of 
1.07 m (42 in.), or a pool with nonmetallic, molded polymeric walls or 
inflatable fabric walls regardless of dimension.
    Switchboard. A large single panel, frame, or assembly of panels on 
which are mounted, on the face or back, or both, switches, overcurrent 
and other protective devices, buses, and usually instruments. 
Switchboards are generally accessible from the rear as well as from the 
front and are not intended to be installed in cabinets. (See 
Panelboard.)
    Switch. (1) General-use switch. A switch intended for use in 
general distribution and branch circuits. It is rated in amperes, and 
it is capable of interrupting its rated current at its rated voltage.
    (2) General-use snap switch. A form of general-use switch 
constructed so that it can be installed in device boxes or on box 
covers, or otherwise used in conjunction with wiring systems recognized 
by this subpart.
    (3) Isolating switch. A switch intended for isolating an electric 
circuit from the source of power. It has no interrupting rating, and it 
is intended to be operated only after the circuit has been opened by 
some other means.
    (4) Motor-circuit switch. A switch, rated in horsepower, capable of 
interrupting the maximum operating overload current of a motor of the 
same horsepower rating as the switch at the rated voltage.
    Switching devices. (Over 600 volts, nominal.) Devices designed to 
close and open one or more electric circuits. Included in this category 
are circuit breakers, cutouts, disconnecting (or isolating) switches, 
disconnecting means, interrupter switches, and oil (filled) cutouts.
    Transportable X-ray. X-ray equipment installed in a vehicle or that 
may readily be disassembled for transport in a vehicle.
    Utilization equipment. Equipment that utilizes electric energy for 
electronic, electromechanical, chemical, heating, lighting, or similar 
purposes.
    Utilization system. A system that provides electric power and light 
for employee workplaces, and includes the premises wiring system and 
utilization equipment.
    Ventilated. Provided with a means to permit circulation of air 
sufficient to remove an excess of heat, fumes, or vapors.
    Volatile flammable liquid. A flammable liquid having a flash point 
below 38[deg]C (100[deg]F), or a flammable liquid whose temperature is 
above its flash point, or a Class II combustible liquid having a vapor 
pressure not exceeding 276 kPa (40 psia) at 38[deg]C (100[deg]F) and 
whose temperature is above its flash point.
    Voltage (of a circuit). The greatest root-mean-square (rms) 
(effective) difference of potential between any two conductors of the 
circuit concerned.
    Voltage, nominal. A nominal value assigned to a circuit or system 
for the purpose of conveniently designating its voltage class (as 120/
240 volts, 480Y/277 volts, 600 volts). The actual voltage at which a 
circuit operates can vary from the nominal within a range that permits 
satisfactory operation of equipment.
    Voltage to ground. For grounded circuits, the voltage between the 
given conductor and that point or conductor of the circuit that is 
grounded; for ungrounded circuits, the greatest voltage between the 
given conductor and any other conductor of the circuit.
    Watertight. So constructed that moisture will not enter the 
enclosure.
    Weatherproof. So constructed or protected that exposure to the 
weather will not interfere with successful operation. Rainproof, 
raintight, or watertight equipment can fulfill the requirements for 
weatherproof where varying weather conditions other than wetness, such 
as snow, ice, dust, or temperature extremes, are not a factor.
    Wireways. Wireways are sheet-metal troughs with hinged or removable 
covers for housing and protecting electric wires and cable and in which 
conductors are laid in place after the wireway has been installed as a 
complete system.
    6. Appendix A to Subpart S of part 1910 would be revised to read as 
follows:

Appendix A to Subpart S of Part 1910--References for Further 
Information

    The following references provide nonmandatory information that 
can be helpful in understanding and complying with Subpart S:
    ANSI/API RP 500-1998 (2002) Recommended Practice for 
Classification of

[[Page 17842]]

Locations for Electrical Installations at Petroleum Facilities 
Classified as Class I Division 1 and Division 2.
    ANSI/API RP 505-1998 (2002) Recommended Practice for 
Classification of Locations for Electrical Installations at 
Petroleum Facilities Classified as Class I, Zone 0, Zone 1 and Zone 
2.
    ANSI/ASME A17.1-2000 Safety Code for Elevators and Escalators.
    ANSI/ASME B30.2-2001 Safety Code for Overhead and Gantry Cranes.
    ANSI/ASME B30.3-1996 Construction Tower Cranes.
    ANSI/ASME B30.4-2003 Portal, Tower, and Pedestal Cranes.
    ANSI/ASME B30.5-2000 Mobile And Locomotive Cranes.
    ANSI/ASME B30.6-2003 Derricks.
    ANSI/ASME B30.7-2001 Base Mounted Drum Hoists.
    ANSI/ASME B30.8-2000 Floating Cranes And Floating Derricks.
    ANSI/ASME B30.11-1998 Monorails And Underhung Cranes.
    ANSI/ASME B30.12-2001 Handling Loads Suspended from Rotorcraft.
    ANSI/ASME B30.13-2003 2003 Storage/Retrieval (S/R) Machines and 
Associated Equipment.
    ANSI/ASME B30.15-Safety Code for Mobile Hydraulic Cranes.
    ANSI/ASME B30.16-2003 Overhead Hoists (Underhung).
    ANSI/IEEE C2-2002 National Electrical Safety Code.
    ANSI K61.1-1999 Safety Requirements for the Storage and Handling 
of Anhydrous Ammonia.
    ANSI/UL 913-2002 Intrinsically Safe Apparatus and Associated 
Apparatus for Use in Class I, II, and III, Division 1, Hazardous 
(Classified) Locations.
    ANSI/UL 2279-1997 Electrical Equipment for Use in Class I, Zone 
0, 1 and 2 Hazardous (Classified) Locations.
    ASTM D3176-1989 (2002) Standard Practice for Ultimate Analysis 
of Coal and Coke.
    ASTM D3180-1989 (2002) Standard Practice for Calculating Coal 
and Coke Analyses from As-Determined to Different Bases.
    NFPA 20-1999 Standard for the Installation of Stationary Pumps 
for Fire Protection.
    NFPA 30-2000 Flammable and Combustible Liquids Code.
    NFPA 32-2000 Standard for Drycleaning Plants.
    NFPA 33-2000 Standard for Spray Application Using Flammable or 
Combustible Materials.
    NFPA 34-2000 Standard for Dipping and Coating Processes Using 
Flammable or Combustible Liquids.
    NFPA 35-1999 Standard for the Manufacture of Organic Coatings.
    NFPA 36-2001 Standard for Solvent Extraction Plants.
    NFPA 40-2001 Standard for the Storage and Handling of Cellulose 
Nitrate Film.
    NFPA 58-2001 Liquefied Petroleum Gas Code.
    NFPA 59-2001 Utility LP-Gas Plant Code.
    NFPA 70-2002 National Electrical Code.
    NFPA 70E-2000 Standard for Electrical Safety Requirements for 
Employee Workplaces.
    NFPA 77-2000 Recommended Practice on Static Electricity.
    NFPA 80-1999 Standard for Fire Doors and Fire Windows.
    NFPA 88A-2002 Standard for Parking Structures.
    NFPA 91-1999 Standard for Exhaust Systems for Air Conveying of 
Vapors, Gases, Mists, and Noncombustible Particulate Solids.
    NFPA 101-2003 Life Safety Code.
    NFPA 496-1998 Standard for Purged and Pressurized Enclosures for 
Electrical Equipment.
    NFPA 497-1997 Recommended Practice for the Classification of 
Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) 
Locations for Electrical Installations in Chemical Process Areas.
    NFPA 505-2002 Fire Safety Standard for Powered Industrial Trucks 
Including Type Designations, Areas of Use, Conversions, Maintenance, 
and Operation.
    NFPA 820-1999 Standard for Fire Protection in Wastewater 
Treatment and Collection Facilities.
    NMAB 353-1-1979 Matrix of Combustion-Relevant Properties and 
Classification of Gases, Vapors, and Selected Solids.
    NMAB 353-2-1979 Test Equipment for Use in Determining 
Classifications of Combustible Dusts.
    NMAB 353-3-1980 Classification of Combustible Dust in Accordance 
with the National Electrical Code.

Appendices B and C [Removed]

    7. Appendices B and C to Subpart S of part 1910 would be 
removed.

[FR Doc. 04-7033 Filed 4-2-04; 8:45 am]
BILLING CODE 4510-26-P