[Federal Register Volume 84, Number 91 (Friday, May 10, 2019)]
[Proposed Rules]
[Pages 20704-20730]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-09218]
[[Page 20703]]
Vol. 84
Friday,
No. 91
May 10, 2019
Part II
Department of Energy
-----------------------------------------------------------------------
10 CFR Part 431
Energy Conservation Program: Test Procedure for Distribution
Transformers; Proposed Rule
Federal Register / Vol. 84 , No. 91 / Friday, May 10, 2019 / Proposed
Rules
[[Page 20704]]
-----------------------------------------------------------------------
DEPARTMENT OF ENERGY
10 CFR Part 431
[EERE-2017-BT-TP-0055]
RIN 1904-AB39
Energy Conservation Program: Test Procedure for Distribution
Transformers
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Notice of proposed rulemaking and request for comment.
-----------------------------------------------------------------------
SUMMARY: The U.S. Department of Energy (``DOE'') proposes clarifying
amendments to the test procedure for distribution transformers to
revise and add definitions of certain terms, to incorporate revisions
based on the latest versions of relevant Institute of Electrical and
Electronics Engineers (IEEE) industry standards, and to specify the
basis for voluntary representations at additional per-unit loads (PULs)
and additional reference temperatures. The proposals in this NOPR are
minor revisions that do not significantly change the test procedure.
Therefore, none of the revisions would pose undue burden on
manufacturers. DOE is seeking comment from interested parties on the
proposal.
DATES: DOE will accept comments, data, and information regarding this
notice of proposed rulemaking (NOPR) no later than July 9, 2019. See
section V, ``Public Participation,'' for details.
ADDRESSES: Any comments submitted must identify the Test Procedure NOPR
for Distribution Transformers and provide docket number EERE-2017-BT-
TP-0055 and/or regulatory information number (RIN) 1904-AB39. Comments
may be submitted using any of the following methods:
(1) Federal eRulemaking Portal: http://www.regulations.gov. Follow
the instructions for submitting comments.
(2) Email: [email protected]. Include
the docket number and/or RIN in the subject line of the message.
(3) Postal Mail: Appliance and Equipment Standards Program, U.S.
Department of Energy, Building Technologies Program, Mailstop EE-5B,
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone:
(202) 287-1445. If possible, please submit all items on a compact disc
(``CD''), in which case it is not necessary to include printed copies.
(4) Hand Delivery/Courier: Appliance and Equipment Standards
Program, U.S. Department of Energy, Building Technologies Program, 950
L'Enfant Plaza SW, Suite 600, Washington, DC 20024. Phone: (202) 287-
1445. If possible, please submit all items on a CD, in which case it is
not necessary to include printed copies.
No telefacsimilies (faxes) will be accepted. For detailed
instructions on submitting written comments and additional information
on the rulemaking process, see section V of this document (Public
Participation).
Docket: The docket, which includes Federal Register notices, public
meeting attendee lists and transcripts, comments, and other supporting
documents/materials, is available for review at http://www.regulations.gov. All documents in the docket are listed in the
http://www.regulations.gov index. However, some documents listed in the
index, such as those containing information that is exempt from public
disclosure, may not be publicly available.
The docket web page can be found at https://www.regulations.gov/docket?D=EERE-2017-BT-TP-0055. The docket web page will contain simple
instructions on how to access all documents, including public comments,
in the docket. See section V for information on how to submit comments
through http://www.regulations.gov.
FOR FURTHER INFORMATION CONTACT:
Mr. Jeremy Dommu, U.S. Department of Energy, Office of Energy
Efficiency and Renewable Energy, Building Technologies Program, EE-5B,
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone:
(202) 586-9870. Email: [email protected].
Ms. Sarah Butler, U.S. Department of Energy, Office of the General
Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585-0121.
Telephone: (202) 586-1777. Email: [email protected].
For further information on how to submit a comment or review other
public comments and the docket, contact the Appliance and Equipment
Standards Program staff at (202) 287-1445 or by email:
[email protected].
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Notice of Proposed Rulemaking
III. Discussion
A. Rulemaking Process
B. Scope
C. Definitions
1. Rectifier Transformers
2. New Definitions
a. Per-Unit Load
b. Terminal
c. Auxiliary Device
3. Updated Definitions
a. Low-Voltage Dry-Type Distribution Transformer
b. Reference Temperature
D. Updates to Industry Standards
1. Updates to NEMA TP 2
2. Updates to IEEE Standards
E. Per-Unit Load Testing Requirements
1. Multiple-PUL Weighted-Average Efficiency Metric
2. Single-PUL Efficiency Metric
3. Other Efficiency Metric Recommendations
4. Voluntary Representations of Efficiency at Additional PULs
F. Purchasing Decision
G. Load Growth
H. Temperature Correction
I. Multiple Voltage Capability
J. Other Test Procedure Topics
1. Per-Unit Load Specification
2. Reference Temperature Specification
3. Measurement Location
4. Specification for Stabilization of Current and Voltage
5. Ambient Temperature Tolerances
6. Field Test Equipment
7. Harmonic Current
8. Other Editorial Revisions
K. Sampling, Representations, AEDMs
L. Test Procedure Costs, Harmonization, and Other Topics
1. Test Procedure Costs and Impact
2. Harmonization With Industry Standards
3. Other Test Procedure Topics
M. Compliance Date and Waivers
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under Executive Orders 13771 and 13777
C. Review Under the Regulatory Flexibility Act
D. Review Under the Paperwork Reduction Act of 1995
E. Review Under the Treasury and General Government
Appropriations Act, 1999
F. Review Under the National Environmental Policy Act of 1969
G. Review Under Executive Order 13132
H. Review Under Executive Order 12988
I. Review Under the Unfunded Mandates Reform Act of 1995
J. Review Under Executive Order 12630
K. Review Under Treasury and General Government Appropriations
Act, 2001
L. Review Under Executive Order 13211
M. Review Under Section 32 of the Federal Energy Administration
Act of 1974
N. Referenced Consensus Standards
V. Public Participation
A. Submission of Comments
B. Issues on Which DOE Seeks Comment
VI. Approval of the Office of the Secretary
I. Authority and Background
DOE is authorized to establish and amend energy conservation
standards
[[Page 20705]]
and test procedures for certain industrial equipment, including
distribution transformers. (42 U.S.C. 6317(a)) The current DOE test
procedures for distribution transformers appear at title 10 of the Code
of Federal Regulations (``CFR'') 431.193 and appendix A to subpart K of
10 CFR part 431 (herein referenced as ``appendix A''). The following
sections discuss DOE's authority to establish and amend test procedures
for distribution transformers, as well as relevant background
information regarding DOE's consideration of test procedures for this
equipment.
A. Authority
The Energy Policy and Conservation Act of 1975, as amended
(``EPCA'') \1\ among other things, authorizes DOE to regulate the
energy efficiency of a number of consumer products and industrial
equipment. (42 U.S.C. 6291-6317) Title III, Part C \2\ of EPCA, added
by Public Law 95-619, Title IV, Sec. 441(a), established the Energy
Conservation Program for Certain Industrial Equipment, which sets forth
a variety of provisions designed to improve energy efficiency. This
equipment includes distribution transformers, the subject of this NOPR.
(42 U.S.C. 6317(a))
---------------------------------------------------------------------------
\1\ All references to EPCA refer to the statute as amended
through America's Water Infrastructure Act of 2018, Public Law 115-
270 (October 23, 2018).
\2\ For editorial purposes, upon codification into the U.S.
Code, Part C was redesignated as Part A-1.
---------------------------------------------------------------------------
Under EPCA, DOE's energy conservation program consists of four
parts: (1) Testing, (2) labeling, (3) Federal energy conservation
standards, and (4) certification and enforcement procedures. Relevant
provisions of EPCA for distribution transformers include definitions
(42 U.S.C. 6291; 42 U.S.C. 6311), energy conservation standards (42
U.S.C. 6295; 42 U.S.C. 6317), test procedures (42 U.S.C. 6293; 42
U.S.C. 6314), labeling provisions (42 U.S.C. 6294; 42 U.S.C. 6315), and
the authority to require information and reports from manufacturers (42
U.S.C. 6316).
Federal energy efficiency requirements for covered equipment
established under EPCA generally supersede State laws and regulations
concerning energy conservation testing, labeling, and standards. (42
U.S.C. 6316)
The Federal testing requirements consist of test procedures that
manufacturers of covered equipment must use as the basis for (1)
certifying to DOE that their products comply with the applicable energy
conservation standards adopted under EPCA (42 U.S.C. 6316(a); 42 U.S.C.
6296), and (2) making representations about the efficiency of those
products (42 U.S.C. 6314(d)). Similarly, DOE must use these test
procedures to determine whether the products comply with any relevant
standards promulgated under EPCA. (42 U.S.C. 6316(a); 42 U.S.C.
6295(s))
Under 42 U.S.C. 6314, EPCA sets forth the criteria and procedures
DOE must follow when prescribing or amending test procedures for
covered equipment. EPCA provides in relevant part that any test
procedures prescribed or amended under this section must be reasonably
designed to produce test results which measure energy efficiency,
energy use and estimated annual operating cost of a covered equipment
during a representative average use cycle or period of use and not be
unduly burdensome to conduct. (42 U.S.C. 6314(a)(2))
In addition, if DOE determines that a test procedure amendment is
warranted, it must publish proposed test procedures and offer the
public an opportunity to present oral and written comments on them. (42
U.S.C. 6314(b)) EPCA also requires that, at least once every 7 years,
DOE evaluate test procedures for each type of covered equipment,
including distribution transformers, to determine whether amended test
procedures would more accurately or fully comply with the requirements
for the test procedures to not be unduly burdensome to conduct and to
be reasonably designed to produce test results that reflect energy
efficiency, energy use, and estimated operating costs during a
representative average use cycle. (42 U.S.C. 6314(a)(1)) If the
Secretary determines that a test procedure amendment is warranted, the
Secretary must publish proposed test procedures in the Federal
Register, and afford interested persons an opportunity (of not less
than 45 days' duration) to present oral and written data, views, and
arguments on the proposed test procedures. (42 U.S.C. 6314(b)) DOE is
publishing this NOPR to satisfy the 7-year review requirement specified
in EPCA. (42 U.S.C. 6314(a)(1)(A))
With respect to distribution transformers, EPCA states that the
test procedures for distribution transformers shall be based on the
``Standard Test Method for Measuring the Energy Consumption of
Distribution Transformers'' prescribed by the National Electrical
Manufacturers Association (NEMA TP 2-1998). (42 U.S.C. 6293(b)(10)(A))
Further, DOE may review and revise the DOE test procedure. (42 U.S.C.
6293(b)(10)(B))
B. Background
DOE's existing test procedure for distribution transformers appears
at 10 CFR 431.193 and appendix A. EPCA directed DOE to prescribe
testing procedures for those ``distribution transformers'' for which
DOE determines that energy conservation standards ``would be
technologically feasible and economically justified, and would result
in significant energy savings.'' (42 U.S.C. 6317(a)(1)) EPCA states
that the testing procedures for distribution transformers shall be
based on the ``Standard Test Method for Measuring the Energy
Consumption of Distribution Transformers'' prescribed by the National
Electrical Manufacturers Association (NEMA TP 2-1998). (42 U.S.C.
6293(b)(10)(A)) Upon establishment of the required test procedures,
EPCA required DOE to establish standards for those distribution
transformers for which test procedures were prescribed. (42 U.S.C.
6317(a)(2)) DOE has established standards for distribution transformers
at 10 CFR 431.196. 70 FR 60407 (October 18, 2005); 78 FR 23336 (Apr.
18, 2013).
Accordingly, DOE prescribed the test procedure for distribution
transformers on April 27, 2006 (hereafter ``April 2006 TP final
rule''). 71 FR 24972. In an April 2013 final rule amending the
standards for distribution transformers (hereafter ``April 2013 ECS
final rule''), DOE determined that the test procedures did not require
amendment at that time, concluding that the test procedure as
established in the April 2006 TP final rule was reasonably designed to
produce test results that reflect energy efficiency and energy use, as
required by 42 U.S.C. 6314(a)(2). 78 FR 23336, 23347-48 (April 18,
2013).
On September 22, 2017, DOE published a request for information
(RFI) to collect data and information to inform its decision in
satisfaction with the 7-year review requirement specified in EPCA
(hereafter ``September 2017 TP RFI''). 82 FR 44347. In response to the
September 2017 TP RFI, National Electrical Manufacturers Association
(NEMA) requested an extension of the comment period. (NEMA, No. 4 at p.
1) DOE published a notice on October 31, 2017, reopening the public
comment period until November 6, 2017. 82 FR 50324.
In this document, DOE is proposing amendments to the test procedure
for distribution transformers. DOE also addresses the comments received
in response to the September 2017 TP RFI.
[[Page 20706]]
II. Synopsis of the Notice of Proposed Rulemaking
In this NOPR, DOE proposes to update 10 CFR 429.47, 431.192,
431.193, 431.196 and appendix A as follows:
(1) Explicitly specify that the test procedure is applicable only
to distribution transformers that are subject to energy conservation
standards,
(2) Include new definitions for ``per-unit load,'' ``terminal'' and
``auxiliary device,'' and updated definitions for ``low-voltage dry-
type distribution transformer'' and ``reference temperature,''
(3) Reflect certain revisions from the latest version \3\ of the
IEEE standards on which the DOE test procedure is based,
---------------------------------------------------------------------------
\3\ 42 U.S.C. 6314(d) generally requires that 180 days after a
test procedure rule applicable to any covered equipment is
prescribed under this section, a manufacturer who makes a
representation of energy consumption of such equipment must test in
accordance with the applicable test procedure. Any voluntary
(optional) representations at additional PULs and/or temperatures
would be required to fairly disclose the results of such testing.
---------------------------------------------------------------------------
(4) Incorporate other clarifying revisions based on review of the
DOE test procedure,
(5) Require manufacturers to use the DOE test procedure to make
voluntary (optional) representations at additional PULs and reference
temperatures,\4\ and
---------------------------------------------------------------------------
\4\ The existing test procedure already includes equations for
producing representations at additional PULs and reference
temperatures.
---------------------------------------------------------------------------
(6) Centralize the per-unit load and reference temperature
specifications for certification to energy conservation standards and
for voluntary representations.
Table II.1 summarizes the proposed test procedure amendments
compared to the current test procedure, as well as the reason for the
change.
Table II.1--Synopsis of the Proposed Test Procedure
------------------------------------------------------------------------
Current DOE TP Proposed TP Attribution
------------------------------------------------------------------------
Current test procedure does States explicitly Clarification added
not specify scope. that the scope of by DOE.
the test procedure
is limited to the
scope of the energy
conservation
standards (10 CFR
431.196). DTs not
subject to ECSs are
not subject to the
TP.
Per-unit load (PUL) is Adds new definition Improves consistency
referred to in the DOE TP for ``per-unit and readability of
as ``percent load,'' load'' (PUL) and test procedure.
``percent of nameplate- consolidates all
rated load,'' ``percent of the terms in
the rated load,'' or ``per subpart K of 10 CFR
unit load level''. part 431 to only
``per-unit load''.
Does not define ``Per-unit Adds new definitions Reflects industry
load,'' ``Terminal'' and for ``Per-unit standard definition
``Auxiliary device,'' which load,'' (terminal) and
are used in the current TP. ``Terminal'' and clarification added
``Auxiliary by DOE (PUL and
device'' based on auxiliary device).
industry IEEE
standards and other
research. (10 CFR
431.192).
Follows four IEEE industry Proposes amendments Reflects industry
standards, which contain that reflect the standard updates.
general electric and latest version of
mechanical requirements and the four IEEE
methods for performing industry standards:
tests: (1) C57.12.00-2015..
(1) C57.12.00-2000.......... (2) C57.12.01-2015..
(2) C57.12.01-1998.......... (3) C57.12.90-2015..
(3) C57.12.90-1999.......... (4) C57.12.91-2011..
(4) C57.12.91-2001.......... (Throughout appendix
A to subpart K of
part 431).
Requires reporting States explicitly Update to reflect
performance at the rated that all testing industry standards.
frequency; however, the under the DOE test
rated frequency is not procedure is to
explicitly stated. occur only at 60
Hz, consistent with
the frequency used
by the US electric
transmission and
distribution
system. (Appendix
A, sections 3.1(c),
4.1).
Requires determining winding Specifies that the Update to reflect
resistance but does not polarity of the industry standards.
specify whether the core magnetization
polarity of the core be kept constant
magnetization should be during all
kept constant as resistance
measurements are made. readings,
consistent with
industry test
method. (Appendix
A, section
3.4.1(f)).
Requires the measurement of Specifies explicitly Update to reflect
load and no-load loss, that load and no- industry standards.
without explicitly load loss
specifying the connection measurements are
locations for measurements. required to be
taken only at the
transformer
terminals.
(Appendix A,
section 3.4.1(g)-
(i)).
Testing with a sinusoidal Specifies that all Update to reflect
waveform explicitly transformers must industry practice.
specified only for be tested using a
transformers designed for sinusoidal waveform
harmonic currents. (not just those
designed for
harmonic current).
(Appendix A,
section 4.1).
Requires that efficiency Permits voluntary Response to industry
must be determined at a representations of comment.
single test per-unit load efficiency, load
(PUL) of 50 percent for loss and no-load
both liquid-immersed and loss at additional
MVDT distribution PULs and/or
transformers, and at a reference
single test PUL of 35 temperature, using
percent for LVDT the DOE TP. Does
distribution transformers. not require
certification to
DOE of any
voluntary
representations.
(Appendix A, new
section 7).
Specifies PUL and reference Centralizes the PUL Improves readability
temperature specifications and reference of test procedure.
for certification to energy temperature
conservation standards in specifications,
multiple locations both for the
throughout appendix A. certification to
energy conservation
standards and for
use with a
voluntary
representation.
(Appendix A, new
sections 2.1 and
2.2).
------------------------------------------------------------------------
[[Page 20707]]
DOE has tentatively determined that the proposed updates would not
change measured values used for certifying compliance with existing
energy conservation standards for distribution transformers or pose
undue test burden. DOE's proposed actions are addressed in detail in
section III of this document.
III. Discussion
The following sections focus on certain aspects of DOE's test
procedure, including rulemaking process, scope and definitions,
revisions based on industry standards, per-unit load (PUL) testing
requirements, purchasing decision, load growth, temperature correction,
multiple voltage capabilities, other test procedure issues and updates,
sampling, representations and alternate efficiency determination method
(AEDM), test procedure costs and harmonization, and compliance date and
waivers. The proposals in this NOPR are minor revisions that do not
significantly change the test procedure. Therefore, none of the
revisions would increase burden on manufacturers. Relevant comments
received in response to the September 2017 TP RFI are addressed in the
appropriate sections in the following discussion. Table III.1 includes
the list of stakeholders that submitted comments.
Table III.1--List of Stakeholders that Submitted Comments *
------------------------------------------------------------------------
Stakeholder listing (and
Stakeholder group abbreviation used in this NOPR)
------------------------------------------------------------------------
Efficiency Advocates.............. American Council for an Energy-
Efficiency Economy and Appliance
Standards Awareness Program (ACEEE
& ASAP).
Manufacturers..................... Howard Industries, NEMA, Powersmiths
International Corp. (Powersmiths),
Prolec-GE.
Utilities......................... American Public Power Association
(APPA), Edison Electric Institute
(EEI), National Rural Electric
Cooperative Association (NRECA),
Pacific Gas and Electric Company,
Southern California Gas Company,
Southern California Edison and San
Diego Gas & Electric Company
(hereafter called California
Investor Owner Utilities, or CA
IOUs).
Steel Producers................... AK Steel, Metglas.
Others............................ HVOLT Inc., Babanna Suresh (Suresh),
Mikro-Kod Consulting (MKC).
------------------------------------------------------------------------
* DOE received other comments from anonymous submitters that were
unrelated to the Distribution Transformer Test Procedure and are
therefore not addressed in this NOPR but are available for review on
the docket. The docket web page can be found at https://www.regulations.gov/docket?D=EERE-2017-BT-TP-0055.
A. Rulemaking Process
In response to the September 2017 TP RFI, DOE received several
comments regarding the rulemaking process.
EEI and APPA stated that DOE should complete work on the test
procedure before issuing any advanced notice of proposed rulemaking
(ANOPR) or ``no new standard'' determination for the energy
conservation standards. (EEI, No. 16 at p. 2; APPA, No. 24 at p. 1) DOE
notes that for rulemakings related to covered equipment, it generally
seeks to follow the process outlined in 10 CFR part 430 subpart C
appendix A, Procedures, Interpretations and Policies for Consideration
of New or Revised Energy Conservation Standards for Consumer Products
(hereafter the ``Process Improvement Rule''). The Process Improvement
Rule provides that, when appropriate and otherwise permissible, any
necessary modifications to a test procedure will be proposed before
issuance of an ANOPR in the standards development process, and a final
test procedure modifying test procedures as necessary will be issued
prior to a NOPR on proposed standards. See section 7(a) and (b). This
document is part of the rulemaking for the test procedure for
distribution transformers. DOE has not initiated a rulemaking regarding
amended standards for distribution transformers, and to the extent DOE
does propose amended standards for distribution transformers, such a
proposal will be addressed in a separate rulemaking.
NEMA commented that it believes there is no need for significant
revisions to test procedures for distribution transformers. (NEMA, No.
14 at p. 2). NRECA and APPA commented that further action to issue new
standards or new test procedures to support new standards is not
necessary for this product category. (NRECA, No. 22 at p. 1; APPA, No.
24 at p. 2) Per EPCA (as discussed in section I.A of this document),
DOE must evaluate test procedures for each type of covered equipment at
least once every 7 years. 42 U.S.C. 6314(a)(1). Consistent with NEMA's
comments, based on DOE's evaluation, the proposals in this NOPR are
minor revisions that do not make significant changes to the test
procedure. Therefore, the proposed amendments would have no impact to
measured values.
CA IOUs urged DOE to work with Institute of Electrical and
Electronics Engineers (IEEE) and the Distribution Transformers
subcommittee to gather the necessary data and information requested in
the RFI. (CA IOUs, No. 18 at p. 1) In response to the September 2017 TP
RFI, DOE received relevant information and data from multiple
stakeholders to inform the test procedure rulemaking. The proposals
presented in this document reflect DOE's consideration of all the
information received in response to the RFI. Through this NOPR, DOE is
providing further opportunity for the public to provide comments,
information, and data on proposed amendments to the test procedure for
distribution transformers.
B. Scope
The applicability of the test procedure is provided in 10 CFR
431.193, which states that ``the test procedures for measuring the
energy efficiency of distribution transformers for purposes of EPCA are
specified in appendix A to this subpart.'' DOE has established energy
conservation standards for low-voltage dry-type (LVDT) distribution
transformers, liquid-immersed distribution transformers, and medium-
voltage dry type (MVDT) distribution transformers at 10 CFR 431.196. In
this NOPR, DOE proposes to state explicitly that the scope of the test
procedure is limited to the scope of the distribution transformers that
are subject to energy conservation standards. DOE proposes to modify
text in 10 CFR 431.193 accordingly.
C. Definitions
This notice proposes clarifying amendments to the test procedure
for distribution transformers. A ``transformer'' is a device consisting
of 2 or more coils of insulated wire that transfers alternating current
by electromagnetic induction from 1 coil to another to change the
original voltage or
[[Page 20708]]
current value. 10 CFR 431.192. A ``distribution transformer'' is a
transformer that: (1) Has an input voltage of 34.5 kV or less; (2) has
an output voltage of 600 V or less; (3) is rated for operation at a
frequency of 60 Hz; and (4) has a capacity of 10 kVA to 2500 kVA for
liquid-immersed units and 15 kVA to 2500 kVA for dry-type units. Id.
The term ``distribution transformer'' does not include a transformer
that is an autotransformer; drive (isolation) transformer; grounding
transformer; machine-tool (control) transformer; nonventilated
transformer; rectifier transformer; regulating transformer; sealed
transformer; special-impedance transformer; testing transformer;
transformer with tap range of 20 percent or more; uninterruptible power
supply transformer; or welding transformer. Id.
A ``liquid-immersed distribution transformer'' is a distribution
transformer in which the core and coil assembly is immersed in an
insulating liquid. Id. A ``low-voltage dry-type distribution
transformer'' is a distribution transformer that has an input voltage
of 600 volts or less; is air-cooled; and does not use oil as a coolant.
Id. A ``medium-voltage dry-type distribution transformer'' means a
distribution transformer in which the core and coil assembly is
immersed in a gaseous or dry-compound insulating medium, and which has
a rated primary voltage between 601 V and 34.5 kV. Id.
In this NOPR, DOE proposes additional specification to the test
procedure scope and instructions. As part of that objective, DOE is
proposing new definitions for two terms: ``terminal'' and ``auxiliary
device.'' Details are provided in sections III.C.2.b and III.C.2.c of
this document. In addition, DOE is proposing minor editorial updates to
the following definitions: ``low-voltage dry-type distribution
transformer'' and ``reference temperature.'' Details are provided in
section III.C.3 of this NOPR.
1. Rectifier Transformers
Rectifier transformers are defined in the CFR to operate at the
fundamental frequency of an alternating-current system and are designed
to have one or more output windings connected to a rectifier. 10 CFR
431.192. Rectifier transformers are among the exclusions to the term
``distribution transformer'' at 10 CFR 431.192. Because rectifier
transformers are not classified as distribution transformers, they are
not subject to the energy conservation standards at 10 CFR 431.196.
Drive transformers are defined in the CFR to isolate electric
motors from the line, accommodate the added loads of drive-created
harmonics, and are designed to withstand the mechanical stresses
resulting from both alternating- and direct-current motors drives. 10
CFR 431.192. Drive transformers are among the exclusions to the term
``distribution transformer'' at 10 CFR 431.192. Although drive and
rectifier transformers are defined differently, they would share many
features. First, both are isolation (i.e., not auto-) transformers.
Second, both are typically exposed to (and must tolerate) significant
drive-/power supply-created harmonic current. Finally, both are likely
to include design features enabling them to bear mechanical stress
resulting from rapid current changes that may arise from operation of
motors and other industrial equipment.
Suresh commented that many distribution transformers supply loads
that may have greater harmonic current due to the ubiquity of
electronics, which typically include rectifiers and which tend to
produce harmonic current. Suresh stated that, as a result, it could be
argued that most distribution-type transformers meet the present
definition of the terms ``rectifier transformer'' or ``drive
transformer.'' Suresh suggested that those terms be removed from the
list of exclusions to the term ``distribution transformer.'' (Suresh,
No. 8 at p. 1) Suresh also suggested that the definition of ``rectifier
transformer'' be limited to transformers that supply loads that are
composed of at least 75 percent power electronics. (Suresh, No. 9 at p.
1)
The definition of ``rectifier transformer'' should not be
interpreted as broadly as the commenter suggests it could be; i.e.,
this term is not intended to describe a large number of transformers
intended for general power distribution service. Linking a definition
of ``rectifier transformer'' to supply of loads composed of greater
than 75 percent power electronics would not be sufficient to designate
a distribution transformer, as it may not be possible for a
manufacturer to know in advance what fraction of the distribution
transformer's load will include power electronics.
DOE reviewed industry standards \5\ and internet-published
manufacturer literature \6\ to identify physical attributes that could
be used to distinguish transformers requiring design modification to
serve large rectifiers and drives from transformers designed for
general-purpose use. In that review, DOE did not observe feature
combinations that could be used to reliably identify rectifier
transformers. For example, DOE did not find a quantification of how
much harmonic current a transformer would need to accommodate to become
suitable for service as a rectifier transformer. Although DOE was not
able to find a candidate replacement definition for ``rectifier
transformer'' (or ``drive transformer'') in review of certain industry
standards and internet-published literature, DOE is interested in
receiving feedback on how such a definition may be identified.
---------------------------------------------------------------------------
\5\ DOE reviewed the following industry standards:
(1) IEEE C57.18.10-1998, ``IEEE Standard Practices and
Requirements for Semiconductor Power Rectifier Transformers''.
(2) IEC 61378-1:2011, ``Converter transformers--Part 1:
Transformers for Industrial Applications''.
(3) IEEE 100-2000, ``The Authoritative Dictionary of IEEE
Standards Terms; Seventh Edition''.
(4) IEC 60050,\5\ ``International Electrotechnical Vocabulary''.
\6\ internet-published literature included product guides,
brochures, manuals, and drawings.
---------------------------------------------------------------------------
DOE requests comment on: (1) Whether the current definition of
rectifier transformer is sufficiently specific, (2) if not, what
modifications would make it sufficiently specific, and (3) whether
partial output phase shift, harmonic current tolerance, or other
electrical properties may be used to reliably identify rectifier
transformers.
DOE requests comment on: (1) Whether the current definition of
drive transformer is sufficiently specific, (2) if not, what
modifications would make it sufficiently specific, and (3) the level of
technical similarity drive transformers bear to rectifier transformers.
2. New Definitions
In this NOPR, DOE proposes to include new definitions for ``per-
unit load,'' ``terminal,'' and ``auxiliary devices.'' Section 5.1 of
Appendix A references ``per-unit load'' in reference to calculation of
load-losses. Appendix A references ``terminal'' in several provisions
regarding test set-up, including in sections 3.3.1.2(c), 3.3.2, and
4.4.2(a)(3). Section 4.4.1 of appendix A provides that measurement
corrections are permitted but not required for losses from auxiliary
devices. Neither ``per-unit load,'' ``terminal,'' nor ``auxiliary
device'' is currently defined in the regulatory text. DOE's
justification for proposing to add these terms is discussed further in
the following sections.
a. Per-Unit Load
A distribution transformer is regularly operated in-service at load
levels less than the full rated load, based on distribution system
design, and fluctuations in customer energy
[[Page 20709]]
demand. Throughout the test procedures and energy conservation
standards for distribution transformers, various terms are used to
refer to a less-than-full rated load, including ``percent load,''
``percent of nameplate-rated load,'' ``percent of the rated load,'' or
``per unit load level.'' 10 CFR 431.192, 10 CFR 431.196, and appendix
A. DOE is proposing to define a single term, ``per-unit load,'' to mean
the fraction of rated load, and to consolidate the usage of these
various terms to the new term ``per-unit load'' in all instances
identified. Consolidating the terms would provide consistency
throughout the DOE test procedure and would affirm that the different
terms have the same meaning.
DOE requests comment on its proposed definition of ``per-unit
load'' and its proposal to consolidate the usage of various terms
referring to less-than-full rated load to the single term ``per-unit
load.''
b. Terminal
DOE is proposing to define ``terminal'' to mean ``a conducting
element of a distribution transformer providing electrical connection
to an external conductor that is not part of the transformer.'' This
definition is based on the definition for ``terminal'' in IEEE
C57.12.80-2010, ``IEEE Standard Terminology for Power and Distribution
Transformers.'' To clarify how losses should be measured, DOE is
proposing to specify that load and no-load loss measurements are
required to be taken only at the transformer terminals, as discussed
further in Section III.J.3 of this document.
DOE requests comment on its proposed definition of ``terminal.''
c. Auxiliary Device
Section 4.5.3.1.2 of appendix A specifies ``during testing,
measured losses attributable to auxiliary devices (e.g., circuit
breakers, fuses, switches) installed in the transformer, if any, that
are not part of the winding and core assembly, may be excluded from
load losses measured during testing.'' DOE has received inquiries from
manufacturers regarding whether certain other internal components of
distribution transformers are required by DOE test procedures to be
included in the loss calculation, or whether they are considered an
auxiliary device. Beyond the listed examples of circuit breakers,
fuses, and switches, the current test procedures do not specify which
other components may be considered auxiliary devices. DOE is not aware
of a prevailing industry definition for the term ``auxiliary device,''
as applied to distribution transformers. The language at section
4.5.3.1.2 of appendix A provides example-based guidance regarding which
components of a distribution transformer are regarded as auxiliary
devices. In this NOPR, however, DOE is proposing to establish a
definition of the term ``auxiliary device'' based on a specific list of
all components and/or component functions that would be considered
auxiliary devices and, therefore, be optionally excluded from
measurement of load loss during testing.
The auxiliary device examples listed at section 4.5.3.1.2 of
appendix A (circuit breakers, fuses, and switches) all provide
protective function, but do not directly aid the transformer's core
function of supplying electrical power. Additionally, the term
``device'' may imply a localized nature, rather than a diffuse system
or property of the transformer.
DOE researched commonly included components in distribution
transformers and identified circuit breakers, fuses, switches, and
surge/lightning arresters as devices which provide protective function
and upon which the transformer does not rely to provide its primary
function of supplying electrical power at a certain voltage.
Accordingly, DOE is proposing to define ``auxiliary device'' to mean
``a localized component of a distribution transformer that is a circuit
breaker, switch, fuse, or surge/lightning arrester.''
DOE requests comment on its proposed definition of ``auxiliary
device,'' and whether certain components should be added or removed
from the listed auxiliary devices and why. DOE also requests comment on
whether it is appropriate to include functional component designations
as part of a definition of ``auxiliary device'' and, if so, which
functions and why.
3. Updated Definitions
a. Low-Voltage Dry-Type Distribution Transformer
As described, the definition of ``low-voltage dry-type distribution
transformer'' specifies that it does not use oil as a coolant, among
other criteria. DOE is proposing to update the definition for ``low-
voltage dry-type distribution transformer'' by replacing the term
``oil'' with ``insulating liquid'' within the definition, in
conjunction with DOE's proposal to consolidate multiple terms to
``insulating liquid,'' as described in section III.D.2 of this
document. DOE is proposing this update to reflect that the term is
inclusive of all insulating liquids, including those identified in IEEE
C57.12.90-2015.
DOE requests comment on its proposed updated definition of ``low-
voltage dry-type distribution transformer.''
b. Reference Temperature
As currently defined at 10 CFR 431.192, ``reference temperature''
means 20 [deg]C for no-load loss, 55 [deg]C for load loss of liquid-
immersed distribution transformers at 50 percent load, and 75 [deg]C
for load loss of both low-voltage and medium-voltage dry-type
distribution transformers, at 35 percent load and 50 percent load,
respectively. It is the temperature at which the transformer losses
must be determined, and to which such losses must be corrected if
testing is done at a different point.
DOE is proposing to update the definition for ``reference
temperature'' by removing references to the numerical temperature
values required for certification with energy conservation standards.
DOE proposes to retain the conceptual definition of reference
temperature and to instead rely on appendix A to specify the numerical
temperature values. As proposed, ``reference temperature'' would mean
the temperature at which the transformer losses are determined, and to
which such losses must be corrected if testing is done at a different
point. This proposal would allow use of the term reference temperature
outside the context of conditions required for certification with
energy conservation standards (i.e., voluntary representations at
additional temperature values, as described in section III.E.4 of this
document).
DOE requests comment on its proposed updated definition of
``reference temperature.''
D. Updates to Industry Testing Standards
The current DOE test procedure for distribution transformers is
based on the following industry testing standards (See 71 FR 24972,
24982 (April 27, 2006)):
NEMA TP 2-1998, ``Standard Test Method for Measuring the
Energy Consumption of Distribution Transformers'' (NEMA TP 2-1998)
IEEE C57.12.90-1999, ``IEEE Standard Test Code for Liquid-
Immersed Distribution, Power and Regulating Transformers and IEEE Guide
for Short Circuit Testing of Distribution and Power Transformers''
IEEE C57.12.91-2001, ``IEEE Standard Test Code for Dry-Type
Distribution and Power Transformers''
[[Page 20710]]
IEEE C57.12.00-2000, ``IEEE Standard General Requirements for
Liquid-Immersed Distribution, Power and Regulating Transformers''
IEEE C57.12.01-1998, ``IEEE Standard General Requirements for
Dry-Type Distribution and Power Transformers Including those with Solid
Cast and/or Resin Encapsulated Windings''
In addition, the DOE test procedure also incorporates relevant parts of
NEMA TP 2-2005, which also references the aforementioned IEEE industry
standards. DOE determined that basing the procedure on multiple
industry standards, as opposed to adopting an industry test procedure
(or procedures) without modification, was necessary to provide the
detail and accuracy required for the Federal test procedure, with the
additional benefit of providing manufacturers the Federal test
procedure in a single reference. 71 FR 24972, 24982 (April 27, 2006).
In the September 2017 TP RFI, DOE requested comments on the
benefits and burdens of adopting industry standards without
modification. 82 FR 44347, 44351 (September 22, 2017). Without
identifying specific benefits, NEMA stated generally that there is
benefit to adopting an industry standard, but if doing so, DOE should
limit the reference to the measurement of losses and retain DOE's
existing calculation for efficiency. (NEMA, No. 14 at p. 9) As stated,
DOE has already based the current test procedure on industry standards
developed by NEMA and IEEE. Additionally, if DOE were to adopt an
industry standard without modification, the resulting changes to the
test procedure could require manufacturers to retest and recertify,
because such an incorporation by reference (IBR) would require updating
a majority of the current test procedure. At this time, DOE is not
proposing to incorporate industry standards into its test procedures
for distribution transformers.
1. Updates to NEMA TP 2
Since the April 2006 TP final rule, NEMA has rescinded NEMA TP 2-
2005.\7\ DOE received one comment regarding the withdrawal; Suresh
commented that because NEMA TP 2 was rescinded, it should not be used
as a reference for determining efficiency for distribution
transformers. Suresh also stated that the current IEEE/ANSI C57.12.00,
C57.12.90 and C57.12.91 are adequate for testing. (Suresh, No. 9 at p.
1)
---------------------------------------------------------------------------
\7\ Standard Test Method for measuring the energy consumption of
distribution transformers, available at: https://www.nema.org/Standards/Pages/Standard-Test-Method-for-Measuring-the-Energy-Consumption-of-Distribution-Transformers.aspx.
---------------------------------------------------------------------------
EPCA requires that DOE base the test procedure on NEMA TP 2-1998.
(42 U.S.C. 6293(b)(10)(A)) As discussed in the previous section, the
DOE test procedure is based on NEMA TP 2-1998, NEMA TP 2-2005, as well
as four widely used IEEE standards, i.e., IEEE.C57.12.00, IEEE
C57.12.01, IEEE C57.12.90 and IEEE C57.12.91. See 71 FR 24972, 24982
(April 27, 2006). In addition, these IEEE standards, are all referenced
standards in NEMA TP 2-2005. Therefore, even though the DOE test
procedure is based on NEMA TP 2-1998 and NEMA TP 2-2005, because the
DOE test procedure also follows the appropriate IEEE standards, DOE
finds that the current stand-alone test procedure is still appropriate.
2. Updates to IEEE Standards
As discussed previously in this section, the DOE test procedure
mirrors four widely used IEEE industry standards.\8\ IEEE develops and
maintains a large number of standards for a broad range of electrical,
electronic, and communications equipment and protocols. Since the April
2006 TP final rule, all of the four IEEE standards have been updated.
The latest versions of the IEEE standards include IEEE C57.12.90-2015,
IEEE C57.12.91-2011, IEEE C57.12.00-2015, and IEEE C57.12.01-2015.
Table III.2 provides a list of old and new versions of each of these
IEEE standards.
---------------------------------------------------------------------------
\8\ The distribution transformers industry refers to these
documents as ``standards'' because they reflect standardized,
consensus-based methods of designing, constructing, naming, rating,
and measuring performance of distribution transformers. This use of
the term ``standards'' contrasts with that of DOE's Appliance
Standards Program use of the term ``standards'' to refer to a
minimum energy efficiency (or maximum energy consumption)
requirement. These IEEE standards do not contain minimal energy
thresholds or requirements.
Table III.2--IEEE Industry Standards Versions and Summary
------------------------------------------------------------------------
Old version New version
IEEE standard (year) (year) Content
------------------------------------------------------------------------
C57.12.00............ 2000 2015 General
electrical and
mechanical
requirements for
liquid-immersed
distribution
transformers.
C57.12.01............ 1998 2015 General
electrical and
mechanical
requirements for
dry-type
distribution
transformers.
C57.12.90............ 1999 2015 Methods for
performing tests
specified in
C57.12.00 and
others for
liquid-immersed
distribution
transformers.
C57.12.91............ 2001 2011 Methods for
performing tests
specified in
C57.12.01 and
others for dry-
type
distribution
transformers.
------------------------------------------------------------------------
DOE reviewed the updated IEEE standards to determine whether any of
the updates should be incorporated into the DOE test procedure. The
four IEEE standards are not relevant to the DOE test procedure in their
entirety, as they include specifications and test methods beyond those
required to measure efficiency, such as test methods for polarity,
phase-relation, dielectric, and audible sound-level. These industry
standards do not contain minimum energy efficiency (or maximum energy
consumption) requirements. DOE performed the review as follows: (1) DOE
identified the sections of the IEEE industry standards that form the
basis of the DOE test procedure, (2) DOE compared those sections
between the old and new versions of the IEEE industry standards, and
(3) DOE determined which of the changes were editorial versus which
could be improvements to the DOE test procedure.
The IEEE C57.12.00 and IEEE C57.12.01 standards include general
electrical and mechanical requirements and specify test methods for
liquid-immersed and dry-type distribution transformers, by referring to
the test methods in IEEE C57.12.90 and IEEE C57.12.91, respectively.
Sections 5, 8, and 9 of IEEE C57.12.90-2015 and IEEE C57.12.91-2011
provide the resistance measurements, the no-load loss test, and the
load loss test, respectively, which provide the basis for the DOE test
procedure. In general, DOE did not find major changes in sections 5, 8,
and 9 between IEEE C57.12.90-2015 and IEEE C57.12.91-2011, and IEEE
C57.12.90-1999 and IEEE C57.12.91-2001, respectively. DOE did identify
certain updates that would provide
[[Page 20711]]
supplemental detail to the current DOE test procedure and that reflect
current industry practice in conducting the test procedure. Therefore,
the adoption of these updates would further improve the DOE test
procedure consistent with industry practice. Table III.3 summarizes the
proposed updates.
Table III.3--Proposed Updates Based on IEEE Standards
------------------------------------------------------------------------
Proposed update based on IEEE
Topic standards
------------------------------------------------------------------------
Consolidating the Terms ``Oil,'' Replace the term ``oil'' and
``Transformer Liquid,'' and ``transformer liquid'' with
``Insulating Liquid''. ``insulating liquid'' in 10
CFR 431.192 and appendix A to
reflect that the term is
inclusive of all insulating
liquids, including those
identified in IEEE C57.12.90-
2015.
Stability Requirement for Resistance Specify, consistent with IEEE
Measurement. C57.12.90-2015, that
resistance measurements are
considered stable if the top
insulating liquid temperature
does not vary more than 2
[deg]C in a one-hour period.
(Appendix A, section
3.2.1.2(b)).
Automatic Recording of Data............ Require automatic recording of
data, as required in IEEE
C57.12.90-2015 and IEEE
C57.12.91-2011, using a
digital data acquisition
system. (Appendix A, section
4.4.2(b)).
Temperature Test System Accuracy....... Relax the temperature test
system accuracy requirements
to be within 1.5
[deg]C for liquid-immersed
distribution transformers, and
2.0 [deg]C for
MVDT and LVDT distribution
transformers, as specified in
IEEE C57.12.00-2015 and IEEE
C57.12.01-2015, respectively.
(Appendix A, section 2.0).
Limits for Voltmeter-Ammeter Method.... Permit use of the voltmeter-
ammeter method when the rated
current of the winding is less
than or equal to 1A. Neither
IEEE C57.12.90-2015 nor IEEE
C57.12.90-2011 restrict usage
of this method to certain
current ranges. (Appendix A,
section 3.3.2(a)).
Number of Readings Required for Include the requirement that a
Resistance Measurement. minimum of four readings for
current and voltage must be
used for each resistance
measurement, as specified in
IEEE C57.12.90-2015. (Appendix
A, section 3.3.2(b)).
Connection Locations for Resistance Add resistance measurement
Measurements. specifications for single-
phase windings, wye windings
and delta windings, as
provided in section 5.4.1 and
5.4.2 of IEEE C57.12.90-2015,
and sections 5.6.1 through
5.6.3 of IEEE C57.12.91-2011.
(Appendix A, section 3.4.1(g)-
(i)).
Test Frequency......................... Require that all testing under
the DOE test procedure is to
occur only at 60 Hz. (Appendix
A, sections 3.1(c), 4.1).
Polarity of Core Magnetization......... Require that the polarity of
the core magnetization be kept
constant during all resistance
readings. (Appendix A, section
3.4.1(f)).
------------------------------------------------------------------------
The proposed updates listed in Table III.2 align with an industry-
consensus standard, and therefore, would not increase testing burden
because the industry-consensus standard reflects current testing
practice. IEEE standards are voluntarily developed by industry with
input from a range of stakeholders and are based on industry
experience. The industry standards represent the industry's own
position on what is the best approach to distribution transformer
testing. Additionally, industry uses IEEE test procedures. For example,
DOE found that municipal distribution transformer procurement contracts
almost always require the transformer be tested in accordance with IEEE
standards. Furthermore, several manufacturer catalogs also indicate
that distribution transformers are tested in accordance with the
pertinent IEEE standards.
The proposals listed in Table III.2 provide additional detail and
direction to the current test procedures. The proposed updates
requiring new or additional test requirements would not contradict the
current DOE test requirements, were they to be made final. As
discussed, these proposed clarifications reflecting the industry
standards are already industry practice. As such, the proposals, if
made final, would not change current measured values. Furthermore,
providing additional specificity would improve the repeatability of the
test procedure.
DOE requests comment on the proposed updates based on the latest
version of the applicable IEEE standards for testing distribution
transformers, and specifically regarding whether industry is already
testing to the requirements of those IEEE standards.
DOE requests comment on the tentative determination that each of
the proposals do not increase test cost or burden, and that they would
not result in different measured values than the current test
procedure.
E. Per-Unit Load Testing Requirements
Per-unit load (PUL) is the actual power supplied by a distribution
transformer, divided by the distribution transformer's rated capacity.
As discussed, it is also referred to as ``percent load,'' ``percent of
nameplate-rated load,'' ``percent of the rated load,'' or ``per unit
load level'' in 10 CFR 431.192, 10 CFR 431.196, and appendix A. In this
NOPR, all instances are referred to as per-unit load, or PUL.
The efficiency of a distribution transformer varies depending on
the PUL at which it is operating. However, the measurements obtained by
testing a distribution transformer at one PUL can be used to
mathematically determine the efficiency of the transformer at other
PULs. For certifying compliance with the energy conservation standards,
the efficiency is determined at a PUL of 50 percent for liquid-immersed
transformers and MVDT distribution transformers, and a PUL of 35
percent for LVDT distribution transformers. 10 CFR 431.196 and appendix
A. The PUL at which the efficiency of a distribution transformer is
evaluated for compliance with the applicable energy conservation
standard is generally referred to as the ``test PUL.'' The test
procedure, however, does not require testing of the distribution
transformer while operating at the test PUL. Section 5.1 of appendix A
provides equations to calculate the efficiency of a distribution
transformer at any PUL based on the testing of the distribution
transformer at a single PUL.
[[Page 20712]]
Current industry practice is to test at 100 percent PUL and
mathematically determine the efficiency at the applicable test PUL.
The test PUL is intended to represent the typical PUL experienced
by in-service distribution transformers. However, some complications
exist, including: (1) A given customer may not operate the transformer
at a single constant PUL, and (2) a transformer model may be used at
different PULs by different customers. In the September 2017 TP RFI,
DOE requested comments and sought information on whether the test PUL
accurately represents in-service distribution transformer performance,
and provides test results that reflect energy efficiency, energy use,
and estimated operating costs during a representative average use cycle
of an in-service transformer. 82 FR 44347, 44350 (September 22, 2017).
In addition, so that the test procedure could better reflect how
distribution transformers operate in service, DOE stated in the
September 2017 TP RFI that it may consider: (1) Revising the single
test PUL to a multiple-PUL weighted-average efficiency metric, (2)
revising the single test PUL to an alternative single test PUL metric
that better represents in-service PUL, or (3) maintaining current
single test PUL specifications. DOE received several comments on this
topic, in addition to potential other metrics for energy conservation
standards. 82 FR 44347, 44350 (September 22, 2017).
DOE received a number of comments stating that in-service PUL is
diverse. (HVOLT, No. 3 at p. 16, Powersmiths, No. 11 at p. 1, NRECA,
No. 22 at p. 2, NEMA, No. 14 at p. 2, EEI, No. 16 at p. 2, Howard
Industries, No. 24 at p. 1) HVOLT stated that transformers are
generally purchased in bulk and largely placed in stock to be applied
as needed, and therefore, the same transformer may be placed in a light
loaded or heavy loaded application. (HVOLT, No. 3 at p. 21) AK Steel
commented that transformers of the same design operate at many
different PULs, and when transformers are operated at higher PULs, the
load loss will far exceed the no-load losses. (AK Steel, No. 6 at p. 1)
NRECA commented that transformers have different efficiencies at
different PULs, and PULs can change over the lifetime of a transformer.
(NRECA, No. 22 at p. 2)
Several stakeholders also submitted information showing how
observed in-service PULs are different than what was presented by DOE
in the September 2017 TP RFI. 82 FR 44347, 44350 (September 22, 2017).
Suresh supported re-assessing the current test PUL requirements to
achieve the benefits of improved efficiency at optimum cost. (Suresh,
No. 9 at p. 1) HVOLT commented that PUL data from loading studies show
light average loads in rural settings and loads greater than 70 percent
in some urban settings and for some commercial and industrial
customers. (HVOLT, No. 3 at p. 16) Summary system load information
provided by HVOLT, and referenced by EEI, of some of California's
Pacific Gas and Electric (PG&E) regional commercial, industrial, and
residential customers show diversity of annual and peak load factors as
a function of what DOE assumes is system capacity. HVOLT also stated
that American Electric Power (AEP) and PECO customer loads are also
similarly diverse. (HVOLT, No. 3 at p. 16; EEI, No. 16 at p. 2) Metglas
stated that PULs of 20 percent to 30 percent are typical of residential
distribution transformers, as reported by APPA and NRECA in a February
2015 letter to the U.S. Environmental Protection Agency (EPA).
(Metglas, No. 17 at p. 4) Howard Industries stated that it provides
liquid-immersed units to rural electrical cooperatives with very light
loading and heavy industrial customers with extremely high loading.
(Howard Industries, No. 24 at p. 1)
Regarding the representativeness of the California data, EEI
reasoned that it is likely that the annual load factors of transformers
serving residential customers in California will be lower than the load
factors of transformers serving homes in other parts of the United
States due to the state's utility electric efficiency programs and
building energy codes. EEI also indicated that the PG&E data is from
2006, and therefore does not account for the significant rise in the
number of plug-in electric vehicles, which could further increase load
factors. (EEI, No. 16 at pp. 2-3)
NEMA commented that it believes that the previous DOE distribution
transformer rulemaking's investigations in typical field loading
practices remain relevant and as accurate as is possible given the high
variations in field conditions.9 10 11 Additionally, NEMA
mentioned certain IEEE studies that indicate that particular utilities
practice very high loading levels, but that EPA's ENERGY STAR
consideration for liquid-immersed distribution transformers showed
several utilities lightly load their transformers, which happens mostly
in rural electric markets. (NEMA, No. 14 at p. 2) APPA and NRECA stated
that a ``one-size-fits-all'' energy conservation standard based on a
single test PUL has restricted availability of the most cost-effective
and energy efficient options. Further, APPA and NRECA stated that it is
not possible to develop an energy conservation standard and test
procedure that take into account the varied loading on a transformer
(both from location to location, and on an hourly and seasonal basis).
APPA and NRECA requested that DOE refrain from any future action with
test procedures or energy conservation standards, stating that there
would only be a burden (no benefit) associated with those changes.
(APPA, No. 24 at p. 2; NRECA, No. 22 at p. 3)
---------------------------------------------------------------------------
\9\ The result of DOE's distribution transformer load analysis
for medium-voltage liquid-immersed distribution transformers are
contained in the Life-cycle Cost and Payback Period spreadsheet
tools for design lines (DL) 1 through 5 on the Forecast Cells tab.
(available at: https://www.regulations.gov/document?D=EERE-2010-BT-STD-0048-0767)
\10\ The result of DOE's transformer load analysis for LVDT
distribution transformers are contained in the Life-cycle Cost and
Payback Period spreadsheet tools for DLs 6 through 8 on the Forecast
Cells tab. (available at: https://www.regulations.gov/document?D=EERE-2011-BT-STD-0051-0085)
\11\ The result of DOE's transformer load analysis for MVDT
distribution transformers are contained in the Life-cycle Cost and
Payback Period spreadsheet tools for DL 9 through 13B on the
Forecast Cells tab. (available at: https://www.regulations.gov/document?D=EERE-2010-BT-STD-0048-0764)
---------------------------------------------------------------------------
DOE appreciates the data and information it received on the topic
of in-service PULs. The data and comments received are consistent with
DOE's understanding that the in-service PULs sustained by transformers
are very diverse. This diversity of PUL is because the application of
distribution transformers is itself diverse, ranging from light-loading
to heavy-loading applications. DOE recognizes that the wide range of
in-service conditions that transformers sustain means that the
efficiency at the test PUL may not reflect the efficiency of any given
transformer at its in-service PUL. The information supplied by
stakeholders was either largely anecdotal, or limited utility customer
meter data from which transformer loads may be inferred as a proxy.
Both anecdotal and utility customer meter data are useful as they frame
generally expected loading limits. Additionally, the customer load data
contains detailed loading characteristics for small, specific
populations. However, DOE notes that both are of limited
representativeness. Given these factors, DOE finds the information
available at this time for describing in-service PUL to be
inconclusive, leaving DOE unable to demonstrate that an alternate test
PUL is more representative than the existing test PUL.
[[Page 20713]]
1. Multiple-PUL Weighted-Average Efficiency Metric
In the September 2017 TP RFI, DOE stated it would consider a
multiple-PUL efficiency metric because the use of a weighted-average
efficiency metric comprised of efficiency at more than one test PUL may
better reflect how distribution transformers operate in service, as
described in this document. As such, DOE requested data and information
to inform a multiple-PUL metric. 82 FR 44347, 44350 (September 22,
2017).
The majority of stakeholders commented that including a multiple-
PUL weighted-average efficiency metric would be overly burdensome on
manufacturers. (HVOLT, No. 3 at p. 24; AK Steel, No. 6 at p. 2;
Powersmiths, No. 11 at p. 2; Prolec-GE, No. 23 at p. 1-2; Howard
Industries, No. 24 at p. 1) Specifically, Powersmiths commented that it
would increase test burden, be difficult to agree on appropriate test
PULs to include, present a consumer education challenge, and
disadvantage small business manufacturers. (Powersmiths, No. 11 at p.
2) Prolec-GE stated that a multiple-PUL weighted-average efficiency
metric would result in suboptimal, higher-cost designs. (Prolec-GE, No.
23 at p. 3) Howard Industries stated that no additional constraints or
alternate metrics should be included because it will be too burdensome
and costly. (Howard Industries, No. 24 at p. 2)
NEMA stated that physical testing at multiple PULs would result in
significant technical challenges to keep winding temperatures managed
under test conditions, adding significant complexity to the test
procedures and introducing new sources for variation. NEMA stated that
these conditions would be unavoidable and their impacts on testing
would serve to further increase differences between test results and
actual in-service conditions. Because of these challenges, NEMA
asserted that testing at one load point is the most feasible method.
(NEMA, No. 14 at p. 5) NEMA commented that currently, transformers are
physically tested at 100 percent PUL and follow-on test points are
calculated, and that this practice should be maintained. NEMA stated
that the existing method is well-proven and well-understood by NEMA
members and other stakeholders in the transformer industry as the best
system to evaluate transformer performance. (NEMA, No. 14 at p. 5) NEMA
also stated that using weighted-average loading in the application of
energy conservation standards without consideration of how it affects
measured efficiency values could be misleading. Adding a weighted-
average formula requirement could also deny a customer who is certain
of their field loading level from buying the most efficient transformer
for their application. NEMA further commented that the current test PUL
requirements allow for sufficient flexibility in field purchasing
decisions today. (NEMA, No. 14 at p. 5)
ACEEE & ASAP commented that DOE should consider the benefits of
ratings based on a weighted average of multiple load points, where
weightings are based on expected hours of operation within bands around
each load point. ACEEE & ASAP provided as an example, ratings based on
the average load point (about 40 percent), and the 25th and 75th
percentile load points (about 30 percent and 50 percent respectively),
which they stated may improve representativeness and foster improved
efficiency in the field. ACEEE & ASAP commented that in no case should
DOE base ratings on extreme load conditions rarely seen in the field.
They also commented that they understand AEDMs to be technically
capable of supplying ratings at any load point and, therefore, that
manufacturers should be able to certify to weighted-average ratings at
very low additional costs. (ACEEE & ASAP, No. 15 at p. 3)
DOE appreciates the comments received regarding the multiple-PUL
weighted-average efficiency metric. Based on comments received, DOE has
tentatively determined that the range of in-service PULs is large, and
varies depending on the application and location of distribution
transformers. DOE recognizes that depending on the procedure for
measuring and calculating the efficiency based on multiple test PULs, a
change of metric may increase the current test burden, due to the need
to re-test and re-certify performance to DOE.\12\ In addition,
consumers would need to be educated on how to interpret the new metric,
which would not correspond to performance at any one test PUL, but
would be based on multiple operating conditions. Lastly, available data
describing this PUL variation is largely anecdotal and insufficient to
show that a multiple-PUL weighted-average efficiency metric is more
representative of in-service PUL than the existing metric.
Specifically, a lack of information is available to determine which
PULs would be appropriate as part of a multiple-PUL weighted efficiency
metric, and how those PULs should be weighted. Given the drawbacks
cited and the lack of evidence at this time to show a weighted-average
metric is more representative than the existing metric, DOE is not
proposing a multiple-PUL weighted-average efficiency metric.
---------------------------------------------------------------------------
\12\ Per-unit testing costs could be identical for a multiple-
PUL metric versus the existing metric, if performance at each PUL is
calculated from a single measurement point (rather than physical
measurements at each PUL).
---------------------------------------------------------------------------
2. Single-PUL Efficiency Metric
In the September 2017 TP RFI, DOE stated that for a single-PUL
efficiency metric, it may consider either continuing to use the current
single test PUL requirements, or revising the single test PUL to an
alternate single test PUL, if it were to better reflect how
distribution transformers operate in service. As such, DOE requested
data and information to inform any changes to the metric. 82 FR 44347,
44350 (September 22, 2017).
A number of stakeholders commented in support of both a single-PUL
efficiency metric and the existing test PUL requirements specified.
(HVOLT, No. 3 at p. 21; Powersmiths, No. 11 at p. 3; NEMA, No. 14 at p.
2; NRECA, No. 22 at p. 3; Prolec-GE, No. 23 at p. 1; Howard Industries,
No. 24 at p. 1) Specifically, Prolec-GE commented that it has not seen
evidence warranting a change from the current 50 percent PUL
requirement for liquid-immersed transformers. Prolec-GE stated that it
is aware that some utilities assumed lower loads, as demonstrated by
their Total Owning Cost (ToC) 13 14 formulas and information
presented during the development of the EPA ENERGY STAR program for
liquid-filled distribution transformers; however, some are higher,
though this is the exception. Prolec-GE stated that utilities do not
know in advance where a transformer will be installed, and that they
also plan for load growth. Therefore, Prolec-GE concluded that 50
percent PUL is reasonable. (Prolec-GE, No. 23 at p. 1) Howard
Industries stated that no additional constraints or alternate metrics
should be included because it would be too burdensome and costly.
(Howard Industries, No. 24 at p. 2)
---------------------------------------------------------------------------
\13\ The Total Owning Cost is the cost savings over the lifetime
of the product, based on the utility's no-load and load loss
evaluation factors. ToC takes into account not only the initial
transformer cost, but also the cost to operate and maintain the
transformer over its lifetime. The ToC formula is provided in the
ENERGY STAR specification for distribution transformers that is
currently under development: (https://www.energystar.gov/products/spec/distribution_transformers_pd).
\14\ U.S. Department of Agriculture and Rural Development, Rural
Utility Service (RUS), Guide for Economic Evaluation of Distribution
Transformers, 2016, Bulletin 1724D-107, https://www.rd.usda.gov/publications/regulationsguidelines/bulletins/electric.
---------------------------------------------------------------------------
ACEEE & ASAP recommended 25 percent PUL for LVDT distribution
[[Page 20714]]
transformers, 35 percent PUL for MVDT distribution transformers and 40
percent PUL for liquid-immersed distribution transformers, in addition
to considering ratings based on a weighted-average PUL. ACEEE & ASAP
stated that these values would be more representative, based on data
provided in the RFI. (ACEEE & ASAP, No. 15 at p. 3) EEI recommended 75
percent PUL for liquid-immersed distribution transformers, if two
single-PUL ratings are not proposed (as discussed in section III.E.1 of
this NOPR). (EEI, No. 16 at p. 4) Powersmiths commented that the
current DOE test procedure at 35 percent PUL for LVDT distribution
transformers does not reflect real world efficiency, and that field
measurements showed most of the market either at less than 15 percent
PUL or greater than 50 percent PUL. However, given the real-world
variability in loading and harmonic content, Powersmiths stated that it
would not be practical or economically viable to establish a revised
test protocol that would capture all these scenarios, as it would be
onerous for the whole industry to follow. (Powersmiths, No. 11 at p. 2)
With respect to test PUL requirements, DOE considered updating the
test PUL requirements to an alternative single test PUL if it were to
better reflect how distribution transformers operate in service. As
discussed in sections III.E and III.E.1, however, DOE has tentatively
determined that the range of in-service PULs is large, and that the
available information describing in-service PUL is inconclusive, which
leaves DOE unable at this time to show that an alternate single test
PUL is more representative of in-service PUL than the existing single
test PUL. DOE recognizes that a change of metric may increase the
current test burden (depending on the procedure for measuring and
calculating efficiency at the new test PUL), due to the need to re-test
and re-certify performance to DOE. Therefore, given the limitations of
the currently available data and lack of a strong indication that an
alternate single test PUL would be more representative than the
existing single test PUL, DOE is not proposing to amend the test PUL
requirements. As such, DOE has tentatively determined to maintain the
current single test PUL requirements in appendix A, which require that
efficiency must be determined at a single test PUL of 50 percent for
both liquid-immersed and MVDT distribution transformers, and that
efficiency must be determined at a single test PUL of 35 percent for
LVDT distribution transformers.
However, DOE agrees there is value in providing a basis for
voluntary representations of additional performance information to
foster better-informed decision-making by consumers. Additional
performance information at other PULs would allow consumers to maximize
transformer efficiency based on their needs. As such, in this NOPR, DOE
is proposing a test procedure for voluntary representations at
additional PULs and/or reference temperatures, which is discussed
further in section III.E.4 of this document.
3. Other Efficiency Metric Recommendations
In addition to the potential use of alternate efficiency metrics on
which DOE requested comment in the September 2017 TP RFI, DOE also
received other recommendations from stakeholders to take under
consideration. AK Steel recommended that DOE implement an efficiency
requirement at 100 percent PUL, in addition to the current test
requirement. (AK Steel, No. 6 at p. 2) EEI commented that based on
factors that could both increase and decrease transformer load, it
supported having two PUL tests for liquid-filled transformers: One at
the current 50 percent PUL and a second at 75 percent PUL. (EEI, No. 16
at p. 4) Howard Industries stated that no additional constraints or
alternate metrics should be included because it will be too burdensome
and costly. (Howard Industries, No. 24 at p. 2)
Metglas recommended DOE use the approach considered by EPA's ENERGY
STAR program, where EPA proposed to expand the number of PULs that
would be optimized to four PULs (25, 35, 50, and 65 percent), in
addition to the ToC process.\15\ Metglas stated that better matching
the purchased unit's actual operating PUL with optimized PULs for those
units could result in significant energy savings. (Metglas, No. 17 at
p. 2) Metglas commented that the addition of a 100 percent PUL only
reduces the competitiveness of all transformers made with low core-loss
material since, to meet the (infrequently observed) 100 percent PUL,
all low core-loss material transformers become more expensive rather
than being the best economic solution for many actual operating PULs.
(Metglas, No. 17 at p. 5) NRECA advocated for the ToC process, similar
to the EPA program, which allows individual utilities to select optimal
designs for their systems and expected PUL. (NRECA, No. 22 at p. 3)
---------------------------------------------------------------------------
\15\ The EPA's ENERGY STAR specification for distribution
transformers (version 1.0) is currently under development. The final
draft specification was published on December 9, 2016 (https://www.energystar.gov/products/spec/distribution_transformers_pd). On
September 27, 2017, EPA published guidance on buying energy
efficient medium-voltage liquid-immersed transformers, which
includes recommended energy efficiency criteria at 25 percent, 35
percent, 50 percent and 65 percent PULs, in addition to using the
ToC equation: https://www.energystar.gov/products/avoiding_distribution_transformer_energy_waste.
---------------------------------------------------------------------------
HVOLT stated that the advent of new low core-loss materials has
created the opportunity for transformers with low no-load loss to carry
greater load losses and remain compliant; the low core-loss
distribution transformers may perform comparatively better than
conventional-core distribution transformers at low PULs and
comparatively worse at high PULs. (HVOLT, No. 3 at p. 22-23) HVOLT
recommended that to limit the potential for large load losses in
transformers built with low core-loss materials, a constraint on total
losses at full load is warranted to ensure that highly loaded
transformers remain efficient. Id. HVOLT suggested that total losses do
not require any new measurements, but would simply be calculated. In
addition, HVOLT recommended a limit which it characterized as an
additional energy conservation standard, on full load total losses as
``limit = 1 + 1/(0.9 x 0.5\2\) x watts'' at 50 percent PUL for medium-
voltage distribution transformers and ``limit = 1 + 1/(0.82 x 0.35\2\)
x watts'' at 35 percent PUL for low-voltage distribution transformers.
HVOLT stated a generous tolerance could also be applied to that limit.
(HVOLT, No. 3 at p. 22)
NEMA, on the other hand, stated that proposals encouraging the
restriction of losses at high PULs are based on very simplistic
assumptions that do not consider the real-life restrictions a design
must meet. NEMA stated that assuming a design can be optimized to have
the peak efficiency at the required PUL, and that the load losses can
be indefinitely increased through greater use of low core-loss
materials like amorphous metal, does not adequately consider other
restrictions transformers have in real life; for example, the capacity
of the cooling system. (NEMA, No. 14 at p. 5)
To summarize, the recommendations for additional metrics as
provided by commenters are: (1) Efficiency requirements at 100 percent
PUL in addition to current DOE requirements, (2) efficiency
requirements at 75 percent PUL in addition to current DOE requirements
at 50 percent PUL for liquid-immersed transformers, (3) optimization at
25, 35, 50 and 65 percent PUL, in addition to the ToC process, similar
to EPA's ENERGY
[[Page 20715]]
STAR guidance, and (4) constraint on total losses, in addition to
current DOE requirements. The above recommendations address issues
beyond the test procedure, i.e., they would result in multiple
standards applicable to a single distribution transformer.
DOE also received comments from Powersmiths stating that customers
incorrectly understand transformers to operate at the minimum
efficiencies required by DOE even at operating conditions that are
different than in the DOE test procedure. (Powersmiths, No. 11 at p. 2)
Powersmiths commented that the current DOE test procedure should
remain, but also require a disclaimer label or associated literature
that the efficiency applies only under ideal linear load (i.e., at the
DOE test PUL), and that actual efficiency may be lower. (Powersmiths,
No. 11 at p. 3) Powersmiths stated that, if manufacturers offer
transformers optimized for other PULs, then they should be required to
back up their performance claims by clearly defining whatever test
protocols are used, supported by audit and by certification to a
recognized testing body. (Powersmiths, No. 11 at p. 3)
As discussed in sections III.E.1 and III.E.2 of this document, any
changes or additional metrics may increase the current test burden, due
to the need to re-test and re-certify performance to DOE. Additionally,
consumers would need to be educated on how to interpret any of the new
metrics recommended in the comments above. Lastly, DOE lacks sufficient
information on in-service PUL to support whether an alternate test PUL
or metric would be more representative of field conditions, so as to
justify requiring testing at that alternate test PUL. Therefore, DOE
finds that proposing a new metric is not justified at this time.
However, to provide manufacturers the opportunity to inform end
users of the performance of a distribution transformer at conditions
other than those required to demonstrate compliance with the DOE
efficiency standard, DOE is proposing to provide explicitly for
voluntary representation at additional PULs and reference temperatures.
Additional representations would allow customers to better predict how
different distribution transformers would operate under the
individualized conditions of that customer. Further discussion on this
proposal is provided in section III.E.4.
4. Voluntary Representations of Efficiency at Additional PULs
DOE received one comment suggesting that public reporting of
additional data would increase consumer information informing
purchasing decisions. In response to the September 2017 TP RFI, MKC
commented that rather than specify one test point, which is typically
at rated voltage and 50 percent load, the test procedure should
determine both no-load loss and load loss. MKC stated that the two
values can determine the efficiency of the transformer under any
loading condition, and that the no-load loss and load loss would be
determined by Clause 8 and 9 from IEEE C57.12.90, or a similar test
method. (MKC, No. 4 at p. 1)
Manufacturers are prohibited under 42 U.S.C. 6314(d) from making
representations respecting the energy consumption of covered equipment
or cost of energy consumed by such equipment, unless that equipment has
been tested in accordance with the applicable DOE test procedure and
such representations fairly disclose the results of that testing. As
discussed, the current DOE test procedure requires that for both
liquid-immersed and MVDT distribution transformers, efficiency is
determined at a single test PUL of 50 percent, and that for LVDT
distribution transformers, efficiency is determined at a single test
PUL of 35 percent. Section 3.5 of appendix A. In addition, efficiency
must be determined at the reference temperature of 20 [deg]C for no-
load loss for all distribution transformers; 55 [deg]C for load loss
for liquid-immersed distribution transformers at the required test PUL
of 50 percent; 75 [deg]C for load loss for MVDT distribution
transformers at the required test PUL of 50 percent; and 75 [deg]C for
load loss for LVDT distribution transformers at the required test PUL
of 35 percent. 10 CFR 431.192. The DOE test procedure specifies
reference temperature requirements only at the test PULs currently
required to comply with the energy conservation standards.
In this NOPR, DOE is proposing amendments to the test procedure to
permit manufacturers to make voluntary representations of additional
performance information of distribution transformers when operated
under conditions other than those required for compliance with the
energy conservation standards for distribution transformers at 10 CFR
431.196. The proposal would help consumers make better purchasing
decisions based on their specific installation conditions. Therefore,
DOE proposes in a new section 7 of appendix A to allow manufacturers to
represent efficiency, no-load loss, or load loss at additional PULs
and/or reference temperatures, as long as the equipment is also
represented in accordance with DOE's test procedure at the mandatory
PUL and reference temperature. When making voluntary representations,
best practice would be for the manufacturers also to provide the PUL
and reference temperature corresponding to those voluntary
representations.
Table III.4 provides a summary of the proposal for voluntary
representations at any PUL.
Table III.4--Summary of Voluntary Representation Proposal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mandatory certified values * Voluntary representations (proposed)
-----------------------------------------------------------------------------------------------------------------------
Reference
temperature Reference temperature
Metric PUL (percent) for load loss Metric PUL (percent) ([deg]C)
([deg]C)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Liquid Immersed................. Efficiency......... 50 55 Efficiency, load Any.................. Any.
loss, no load loss.
MVDT............................ 50 75
LVDT............................ 35 75
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Efficiency must be determined at a reference temperature of 20 [deg]C for no-load loss for all distribution transformers.
[[Page 20716]]
DOE requests comment on the proposal to amend the DOE test
procedure to permit manufacturers to make voluntary representations at
any additional PUL and/or reference temperature, and whether this would
assist consumers in making better purchasing decisions based on their
specific installation conditions. DOE requests comment on whether the
current DOE test procedure would be appropriate at non-mandatory PULs
and reference temperatures.
F. Purchasing Decision
While a customer can specify that transformer efficiency be
optimized to their in-service PUL, the transformer must also comply
with the energy conservation standard at the test PUL. The lowest-cost
transformer design would likely have an efficiency peak at or near the
test PUL, and that the low-cost transformers would experience reduced
efficiency when operated at PULs other than the test PUL. Therefore,
considering there may be variation between the test PUL specified in
the test procedure and actual in-service use, DOE requested comment on
the extent to which efficiency is considered for transformer purchasing
decisions.
DOE received several comments from stakeholders indicating that
first cost is the primary driver for purchasing decisions. HVOLT
commented that efficiency is only considered for simple verification
that the transformer is DOE-compliant. Beyond that, HVOLT asserted,
purchase decisions are mostly made on price, delivery and other user
specifications. (HVOLT, No. 3 at p. 17) AK Steel stated that it has
consistently seen that when purchasing transformers, first cost,
including transformer cost plus installation, is the primary driver in
purchasing decisions. (AK Steel, No. 6 at p. 2)
In addition, DOE received several comments stating that most
manufacturers and customers ensure only that transformers are DOE
compliant when considering efficiency. Specifically, AK Steel, which
produces electrical steel used in distribution transformers, stated
that performance exceeding the DOE energy conservation standard is not
a consideration when AK Steel prices its electrical steel. (AK Steel,
No. 6 at p. 2) AK Steel commented that transformer efficiency at
current test PULs have little influence on transformer efficiency at
higher PULs, which AK Steel states is especially apparent when lower-
cost, less-efficient windings are used. AK Steel asserts that as a
result, users will purchase DOE-compliant transformers that have
significantly lower efficiency than more appropriately designed units
for in-service PULs. (AK Steel, No. 6 at p. 1)
Metglas, which also produces electrical steel used in distribution
transformers, suggests that by allowing those purchasing distribution
transformers the opportunity to better match projected operating
conditions with transformers better optimized for those conditions that
significant energy saving could be realized. (Metglas, No. 17 at p. 2)
Powersmiths recognized DOE's identification of the business opportunity
for transformer manufacturers to produce application-specific
optimization that can realize low transformer lifecycle cost to
customers, but stated that this opportunity has been ignored by
manufacturers. (Powersmiths, No. 11 at p. 2) NEMA stated that some
utility customers who know their anticipated loading do seek
information from their transformer supplier about whether a transformer
can be designed to meet best efficiency at that PUL. (NEMA, No. 14 at
p. 3)
However, Powersmiths stated that despite smaller manufacturers
having more flexibility to provide application-specific models that
deliver increased efficiency in each targeted application, these
manufacturers do not typically offer additional choices beyond what is
required by the DOE test procedure. Additionally, having a multitude of
models optimized for different applications is not compatible with the
low cost, high volume manufacturing and distribution model, which
drives the fewest product configurations. (Powersmiths, No. 11 at pgs.
2-3) Powersmiths further commented that manufacturers design their
transformers with peak efficiency at the single DOE test PUL to the
detriment of all other operating conditions, such that they are the
lowest cost supplier in the competitive market. (Powersmiths, No. 11 at
p. 2) Prolec-GE similarly stated that it does not see benefit in
representing efficiency at a level higher than the DOE minimum, because
most customers only want assurance that the transformer is compliant.
(Prolec-GE, No. 23 at p. 5) NEMA further stated that while a
transformer can be designed to be optimized for PULs other than DOE's
test PUL, it must also meet the current DOE efficiency standard, and
the two are not necessarily the same, and in many cases, the two
efficiency points cannot be reconciled in a feasible design and
manageable cost. (NEMA, No. 14 at p. 3)
DOE also received several other comments regarding other ways
customers evaluate their purchasing decisions. NEMA stated that members
in liquid-filled product categories seek specifications from customers
which include ToC as a way of addressing efficiency in the purchasing
decision process. However, NEMA stated that ToC does not guarantee that
the resulting design will exceed the current DOE efficiency levels by
any appreciable margin. NEMA commented that the NEMA dry-type
manufacturers rarely experience ToC requests. NEMA stated that there is
a niche market for high efficiency LVDT distribution transformers, but
the size of the market is unknown to NEMA members. For MVDT
distribution transformers, NEMA stated that efficiency does not appear
to be a significant consideration; price and delivery remain top
considerations. (NEMA, No. 14 at p. 3) Prolec-GE stated that 30 to 40
percent of its customers (mostly in rural utility service and rural
electric cooperative markets) evaluate, and half end up buying the best
ToC choice. (Prolec-GE, No. 23 at p. 2) Prolec-GE further stated
meeting the DOE standard at 50 percent PUL and customer ToC formula can
be challenging without pushing first cost too high. (Prolec-GE, No. 23
at p. 2) Howard Industries commented that approximately 50 percent of
its utility customers are still using the ToC approach when purchasing
liquid-immersed transformers. (Howard Industries, No. 24 at p. 1)
DOE acknowledges that many transformers are designed such that
their efficiency peaks at the DOE test PULs, which will allow for the
lowest costs. DOE also acknowledges that some transformers are
optimized at PULs other than those required by DOE's test procedure.
DOE also notes that customers use several different methods to
determine the appropriate distribution transformers for their
application, including the ToC method. DOE's requirements do not
restrict the use of any of the purchasing decision methods, as long as
both the test procedure and standards requirements are met.
As described previously in section III.E.4 of this NOPR, in an
effort to provide manufacturers greater opportunity to describe
equipment performance at additional PULs, DOE is proposing amendments
to the DOE test procedure that would allow manufacturers to make
voluntary representations at additional PULs and reference
temperatures, using the DOE test procedure. Manufacturers would still
be required to comply with the current energy conservation standards
requirements but would be allowed to voluntarily represent their
equipment at
[[Page 20717]]
a variety of PUL conditions. This information could be used by
consumers to make better informed purchasing decisions based on their
specific installation conditions.
G. Load Growth
In the September 2017 TP RFI, DOE discussed estimates for the load
growth of distribution transformers used in the April 2013 ECS final
rule. 82 FR 33437, 44349. These estimates contribute to the description
of typical loading experienced by a distribution transformer in-
service. DOE estimated a one percent annual increase over the life of
the transformer to account for connected load growth for liquid-
immersed transformers, and no load growth over the life of LVDT and
MVDT distribution transformers. DOE requested comments regarding the
load growth estimate over the life of distribution transformers
currently being installed, and how that could inform test requirements
in the DOE test procedure. Id.
DOE received several comments on this topic. HVOLT stated that it
does not have any hard data on the load growth estimate over the life
of the distribution transformer. HVOLT commented that utilities are
generally focused on peak power demand, as non-peak loading does little
to affect distribution system design needs, and that load growth
normally results from new customers or loads being added to existing
circuits. In addition, HVOLT stated that the expanded electrification
of motor vehicles and new commercial and industrial processes are
likely to increase the load on MVDT distribution transformers. On the
other hand, HVOLT commented that the loads on LVDT distribution
transformers may be relatively constant. (HVOLT, No. 13 at p. 17)
ACEEE & ASAP commented that a 0.5 percent growth rate is consistent
with the EIA's Annual Energy Outlook 2017 projected load growth of 0.56
percent per year in its reference case. (ACEEE & ASAP, No. 15 at p. 2)
EEI commented that it believes the overall trends in load could be
increasing over time given some of the significant changes occurring in
the electricity industry. Specifically, the trends include the
deployment of Smart Grid technologies, the increased variability of
distributed and renewable energy sources at different times of day in
renewable distributed generation systems, increased deployment of
electric transportation options, and the increased electrification of
industrial and other operations; and asks that any change in the test
procedure account for these changes. (EEI, No. 16 at p. 3) NRECA stated
that it is not possible to tell if load factors over the lifetime of
transformers will decrease due to energy efficiency or greatly increase
due to penetration of electric vehicles and other distributed energy
resources. (NRECA, No. 22 at p. 2)
DOE appreciates the comments and opinions submitted on the topic of
load growth sustained by in-service transformers. As commenters noted,
a number of trends and factors may impact the load growth realized by
distribution transformers and that some of these trends would have
opposing impacts (e.g., improvements in efficiencies versus the
increased penetration of electric vehicles). At the present, DOE does
not have sufficient data to propose changing the current test procedure
to account for transformer load growth. However, DOE will continue to
examine trends in transformer load growth and may address the issue as
necessary and feasible in any future rulemaking.
H. Temperature Correction
DOE's current test procedure specifies temperature correction of
measured loss values, a process that calculates the losses of a
transformer as though its internal temperature during testing were
equal to a ``reference'' temperature. The reference temperature
provides a common point of comparison, so that the effect of
temperature on efficiency is diminished. If transformers in service do
not reach the same internal temperature (under identical operating
conditions, including ambient temperature and PUL), temperature
correction may weaken the ability of the test procedure to predict
relative in-service performance. In the September 2017 TP RFI, DOE
requested comments, data and information on whether the current
temperature correction is appropriate or whether alternative approaches
should be considered. 82 FR 44347, 44350 (September 22, 2017) DOE
received several comments on the September 2017 TP RFI regarding this
topic. All supported maintaining the current requirements.
Several comments directly supported the current method of
temperature correction. Howard Industries stated that the current
method for temperature correction is appropriate and applicable.
(Howard, No. 24 at p. 1) NEMA commented that the temperature conditions
may vary greatly during operation, and that use of a common reference
temperature allows the DOE test procedure to fairly compare different
products. (NEMA, No. 14 at p. 4) Accordingly, NEMA suggested that the
current test procedure requirements for temperature correction are
adequate. NEMA also stated that internal temperature of a transformer
is driven by both electrical losses and cooling ability. Cooling
ability changes as a function of ambient temperature, which may vary
widely even for a single design. In addition, cooling ability is
closely coupled with design features that also affect many other
electrical and mechanical characteristics of the unit. NEMA stated that
as a result, developing a characteristic relationship between operating
temperature and PUL is quite difficult. NEMA stated that maintaining
the 75 [deg]C reference temperature provides consistency and is the
best approach given the uncertainty [in true operating temperature].
(NEMA, No. 14 at p. 4) NEMA further commented that any change in
requirements would cause performance data across current and future
designs to become noncomparable. (NEMA, No. 14 at p. 4) NEMA also
commented that modifications to the existing internal temperature
correction methodology and test PUL requirement, which would require
adjustment to temperature correction requirements, would cause
manufacturers significant burden. (NEMA, No. 14 at p. 4)
Other comments concurred with the general concept of temperature
correction. HVOLT stated that temperature generally rises with load
current to the 1.6 power under steady state conditions. (HVOLT, No. 3
at p. 19) HVOLT further stated that temperature correction is not of
significant concern, because even when it is performed, the true
temperature of tested transformers is accurately measured and recorded.
(HVOLT, No. 3 at p. 19) Howard Industries commented that temperature
will rise with increasing PUL; winding rises are generally designed to
meet 65 [deg]C rise at full load. (Howard Industries, No. 24 at p. 1)
After further consideration, including the comments received, DOE
is not proposing changes to the current temperature correction
requirements. In response to NEMA's comment that transformer operating
temperature is a function of heat buildup, ambient conditions, and
transformer cooling design, DOE observes that, while it is true that no
single reference temperature could represent all operating conditions,
it may be possible to develop a methodology that accounts for heat
buildup and transformer cooling design. DOE may explore the possibility
in a future notice.
[[Page 20718]]
I. Multiple Voltage Capability
Some distribution transformers have primary windings
(``primaries'') and secondary windings (``secondaries'') that may each
be reconfigured, for example either in series or in parallel, to
accommodate multiple voltages. Some configurations may be more
efficient than others. Such transformers are often purchased with the
intent of upgrading the local power grid to a higher operating voltage
and thereby reducing overall system losses.
Section 4.5.1(b) of appendix A requires that for a transformer that
has a configuration of windings that allows for more than one nominal
rated voltage, the load losses must be determined either in the winding
configuration in which the highest losses occur, or in each winding
configuration in which the transformer can operate. Similarly, section
5.0 of appendix A states that for a transformer that has a
configuration of windings that allows for more than one nominal rated
voltage, its efficiency must be determined either at the voltage at
which the highest losses occur, or at each voltage at which the
transformer is rated to operate. Under either testing and rating option
(i.e., testing only the highest loss configuration, or testing all
configurations), the winding configuration that produces the highest
losses must be tested and consequently must comply with the applicable
energy conservation standard.
Whereas IEEE directs distribution transformers to be shipped with
the windings in series,\16\ a manufacturer physically testing for DOE
compliance may need to disassemble the unit, reconfigure the windings
to test the configuration that produces the highest losses, test the
unit, then reassemble the unit in its original configuration, which
adds time and expense.
---------------------------------------------------------------------------
\16\ Institute of Electrical and Electronics Engineers, Inc
(IEEE); IEEE Standard General Requirements for Liquid-Immersed
Distribution, Power, and Regulating Transformers, 2017, IEEE
Standard C57.12.00-2015, https://standards.ieee.org/findstds/standard/C57.12.00-2015.html.
---------------------------------------------------------------------------
NEMA stated that the majority of distribution transformers are used
in service in the highest-voltage configuration and that some
transformers will have slightly higher losses in the lowest-voltage
configuration. NEMA stated that, based on its calculations, the
difference in load loss between the as-shipped version as compared to
the highest loss configuration is no more than two percent. NEMA
further asserts that the difference in testing as-shipped versus
highest-loss configuration has minimal impact in determining the
numerical value of efficiency, and that the difference is smaller than
the error introduced by the DOE formula for scaling load loss to the
specified test PUL. (NEMA, No. 14 at p. 6) Prolec-GE commented that
switching to as-shipped voltage configuration would improve reliability
and reproducibility because it would facilitate more physical testing
of transformers, and would improve representativeness because it would
better align with performance experienced by users. (Prolec-GE, No. 23
at p. 4) Prolec-GE also stated that it uses an AEDM and supports its
continued allowance because reconfiguring transformers from the as-
shipped winding configuration would be quite costly. (Prolec-GE, No. 23
at p. 4) Both Prolec-GE and NEMA suggested that DOE should harmonize
with industry standards and practices by permitting testing in the as-
shipped winding configuration. (Prolec-GE, No. 23 at p. 6, NEMA, No. 14
at p. 6)
DOE recognizes that, for manufacturers physically testing their
transformers, reporting losses in the same configuration in which the
transformers are shipped, which IEEE instructs to be the in-series
configuration, may be less burdensome than requiring testing in the
configuration that produces the highest losses.\17\ DOE notes, however,
that neither Prolec-GE nor NEMA provided transformer design data to
support their claim that the difference in losses would be minimal when
comparing between transformers rated ``as-shipped'' versus the current
requirement that transformers be rated in their highest loss
configuration. Conversely, the losses of different winding positions
can vary considerably and, as a result, no single winding configuration
will always yield the greatest loss (or lowest efficiency) for all
distribution transformers. Manufacturers may decide to test in multiple
or all configurations to find the highest loss configuration. DOE
remains concerned that there is no reliable way to predict in which
winding configuration a transformer will be operated over the majority
of its lifetime.
---------------------------------------------------------------------------
\17\ Ibid.
---------------------------------------------------------------------------
Furthermore, as an alternative to physical testing, DOE provides
for certification using an AEDM, which is a mathematical model based on
the transformer design. 10 CFR 429.47. The shipped configuration has no
bearing on the AEDM calculation, and an AEDM can determine the highest-
loss configuration instantly. The current requirement to test and
certify based on the highest-loss configuration of the windings confers
a consumer benefit by ensuring the consumer receives at least the
tested level of performance. 71 FR 24972, 24985 (April 27, 2006). DOE
notes that most transformers are currently certified using the AEDM.
Further, changing the requirement of testing in the configuration
from producing the highest losses to ``as-shipped'', may increase the
calculated efficiency, changing the basis upon which existing energy
conservation standards were established. The losses between different
winding configurations can be significant, and to avoid potential
backsliding DOE would need to amend its energy conservation standard to
account for testing in a different configuration.\18\ This could also
necessitate the need for manufacturers of transformers with multiple
windings to re-test and re-certify their performance to DOE.
---------------------------------------------------------------------------
\18\ EPCA contains what is known as an ``anti-backsliding''
provision, which prevents the Secretary from prescribing any amended
standard that either increases the maximum allowable energy use or
decreases the minimum required energy efficiency of a covered
equipment. (42 U.S.C. 6295(o)(1); 42 U.S.C. 6316(a))
---------------------------------------------------------------------------
Based on these considerations, DOE is not proposing to amend the
requirement relating to winding configuration.
DOE requests comment on secondary winding configurations. DOE also
requests comment on the magnitude of the additional losses associated
with the less efficient configurations as well as the relative period
of operation in each winding configuration.
J. Other Test Procedure Topics
In addition to the proposed updates to the DOE test procedure
provided in the preceding sections, DOE also considered whether the
existing test procedure would benefit from any further revisions and/or
reorganizing. Additional issues are discussed in the following section.
1. Per-Unit Load Specification
DOE proposes to centralize the PUL specifications, both for the
certification to energy conservation standards and for use with a
voluntary representation. Currently, the PUL for certification to
energy conservation standards is specified in multiple locations,
including 10 CFR 431.192 (definition of reference temperature), 10 CFR
431.196, section 3.5(a) of appendix A, and section 5.1 of appendix A.
DOE proposes to consolidate the PUL specification into one location--a
newly proposed section 2.1 of appendix A. Additionally, DOE proposes to
provide in the proposed section 2.1 of appendix A that the PUL
specification can be any
[[Page 20719]]
value for purposes of voluntary representations. The consolidation
would enhance readability of the test procedure and more clearly
communicate DOE's PUL requirements with respect to certification to
energy conservation standards and voluntary representations. The
updates do not change existing test PUL requirements with respect to
certification to energy conservation standards. Instead, the updates
improve clarity with respect to selection of PUL for voluntary
representations versus certification to energy conservation standards.
DOE also proposes editorial changes to section 5.1 of appendix A to
support the consolidated approach to PUL specification. Section 5.1
contains equations used to calculate load-losses at any PUL. Section
5.1 of appendix A uses language that limits its applicability to
certification to energy conservation standards only. For example, it
references the ``specified energy efficiency load level'' (i.e., the
PUL required for certification to energy conservation standards)
specifically. DOE proposes to generalize the language in this section
to reference the PUL selected in the proposed section 2.1.
2. Reference Temperature Specification
Similar to PUL, DOE proposes to consolidate the reference
temperature specifications for certification to energy conservation
standards and for the proposed voluntary representations. Currently,
the reference temperature for certification to energy conservation
standards is described in multiple locations, including 10 CFR 431.192
(definition of reference temperature), section 3.5(a) of appendix A,
and section 4.4.3.3 of appendix A. DOE proposes to consolidate the
reference temperature specification into one location--a newly proposed
section 2.2 of appendix A. Additionally, DOE proposes to describe in
the proposed section 2.2 of appendix A that the reference temperature
specification can be any value for purposes of voluntary
representations. Similar to PUL, this consolidation would enhance
readability of the test procedure and more clearly communicate DOE's
reference temperature requirements with respect to certification to
energy conservation standards or voluntary representations. The updates
do not change existing reference temperature requirements with respect
to certification to energy conservation standards. Instead, the updates
improve clarity with respect to selection of reference temperature for
voluntary representations versus certification to energy conservation
standards.
DOE also proposes editorial changes to section 3.5 and section
4.4.3.3 of appendix A to support the consolidated approach to reference
temperature specification. Section 3.5 of appendix A provides reference
temperatures for certification to energy conservation standards.
However, considering DOE has consolidated reference temperature
specifications into one location (proposed section 2.2), DOE has
removed the same specification in section 3.5 so that the section could
be applicable to determine voluntary representations.
Section 4.4.3.3 of appendix A provides the specifications and
equations used for correcting no-load loss to the reference
temperature. Specifically, the section provides an option for no
correction if the no-load measurements were made between 10 [deg]C and
30 [deg]C. This tolerance is only applicable for certification to
energy conservation standards (it is a 10 [deg]C range
around the 20 [deg]C reference temperature). For simplicity, DOE
proposes no such tolerance for voluntary representations at additional
reference temperatures, so that all measured values would be adjusted
using the reference temperature correction formula. Finally, DOE
proposes to remove any reference to a reference temperature of 20
[deg]C so that the section would be applicable to determine voluntary
representations.
3. Measurement Location
DOE proposes to specify that load and no-load loss measurements are
required to be taken only at the transformer terminals. Accordingly, in
this NOPR, DOE has proposed a definition for ``terminal,'' as described
in section III.C.2.b. DOE notes that section 5.4 of IEEE.C57.12.90-2015
and section 5.6 of IEEE C57.12.91-2011 specify terminal-based load-loss
measurements. In addition, section 8.2.4 of both IEEE.C57.12.90-2015
and IEEE C57.12.91-2011 provides the same for no-load loss measurement.
These documents reflect current industry practices and manufacturers
are already measuring losses at the transformer terminals. Therefore,
in this NOPR, DOE proposes to specify in section 4.3(c) of appendix A
that both load loss and no-load loss measurements must be made from
terminal to terminal.
4. Specification for Stabilization of Current and Voltage
Section 3.3.2 and 3.3.1 of appendix A describe a voltmeter-ammeter
method and resistance bridge methods, respectively, for measuring
resistance. Both methods require measurements to be stable before
determining the resistance of the transformer winding being measured.
Specifically, the voltmeter-ammeter method in section 3.3.2(b) of
appendix A requires that current and voltage readings be stable before
taking simultaneous readings of current and voltage to determine
winding resistance. For the resistance bridge methods, section 3.3.1 of
appendix A requires the bridge be balanced (i.e., no voltage across it
or current through it) before determining winding resistance. Both
methods allow for a resistor to reduce the time constant of the
circuit, but do not explicitly specify how to determine when
measurements are stable. DOE notes that IEEE C57.12.90-2015, IEEE
C57.12.91-2011, IEEE C57.12.00-2015, and IEEE C57.12.01-2015 do not
specify how to determine that stabilization is reached. Section 3.4.2
of appendix A provides related guidelines for improving measurement
accuracy of resistance by reducing the transformer's time constant.
However, section 3.4.2 also does not explicitly provide for the period
of time (such as a certain multiple of the time constant) necessary to
achieve stability. In this NOPR, DOE is seeking further information on
how industry currently determines that measurements have stabilized
before determining winding resistance using both voltmeter-ammeter
method and resistance bridge methods.
DOE requests comments regarding when, or at what number of time
constants, stability is reached for the voltmeter-ammeter method and
the resistance bridge method.
5. Ambient Temperature Tolerances
In response to the September 2017 TP RFI, DOE received one comment
concerning potential burden arising from the requirement to maintain
the temperatures of both the testing laboratory and the transformer
within certain ranges. Specifically, NEMA recommended that DOE increase
the temperature tolerances when testing dry-type transformers, which
require maintaining the laboratory ambient temperature within a range
of 3 [deg]C for 3 hours before testing, and maintaining transformer
internal temperature (if ventilated) or surface temperature (if sealed)
within 2 [deg]C of the laboratory ambient temperature.
NEMA stated that these temperature limits may be burdensome in
laboratories that are not climate controlled, and that an alternate
method to the temperature limits may be a development of a mathematical
correction factor. NEMA acknowledged, however, that in the experience
of its
[[Page 20720]]
membership, the temperature requirements generally presented little
challenge.
As stated, EPCA requires that DOE establish test procedures that
are not unduly burdensome to conduct. Whereas widening tolerances of
temperatures (or other measured parameters) may reduce testing cost, it
may impact the reproducibility and repeatability of the test result. In
the case of these particular temperature boundaries, that NEMA's
membership is generally not experiencing difficulty in meeting them may
suggest that they are appropriately sized. DOE does not have data
regarding typical ranges of laboratory ambient temperature and, as a
result, cannot be certain that reduction in temperature tolerance would
not harm reproducibility, repeatability, and accuracy and cause future
test results to become incomparable to past data. For these reasons,
DOE is not proposing amendments to the laboratory ambient temperature
and transformer internal temperature requirements.
DOE seeks comment on its proposal to maintain the laboratory
ambient and transformer internal temperature requirements with no
changes.
6. Field Test Equipment
MKC commented regarding potential difficulties inherent in using
conventional test equipment with deployed, operational distribution
transformers. MKC described and recommended alternative test equipment.
(MKC, No. 4 at pp. 1-2) DOE observes that manufacturers and other
parties testing distribution transformers are free to use any variety
of equipment that meets the requirements set forth in appendix A.
7. Harmonic Current
Harmonic current refers to electrical power at alternating current
frequencies greater than the fundamental frequency. In electrical power
applications, harmonic current is typically regarded as undesirable;
nonetheless, distribution transformers in service are commonly subject
to (and must tolerate) harmonic current of a degree that varies by
application. Test procedures for distribution transformers at sections
4.4.1(a) and 4.4.3.2(a) of appendix A direct use of a sinusoidal
waveform when evaluating efficiency in distribution transformers.
Regarding test setup, Powersmiths commented that it would not be
practical for the test procedure to address the harmonic content
experienced in every customer's installation. (Powersmiths, No. 11 at
p. 2) DOE recognizes that transformers in service are subject to a
variety of harmonic conditions, and that the test procedure must
provide a common basis for comparison. Currently, the test procedure
states that transformers designed for harmonic currents must be tested
with a sinusoidal waveform (i.e., free of harmonic current), but does
not do so for all other varieties of transformers. However, the intent
of the test procedure is for all transformers to be tested with a
sinusoidal waveform, as is implicit in section 4.4.1(a) of appendix A.
To clarify this test setup requirement, DOE proposes to modify section
4.1 of appendix A to read ``. . . Test all distribution transformers
using a sinusoidal waveform (k=1).'' This is consistent with industry
practice and manufacturers are already testing all distribution
transformers using a sinusoidal waveform.
DOE seeks comment on its proposal to modify section 4.1 of appendix
A to read ``. . . Test all distribution transformers using a sinusoidal
waveform (k=1).''
8. Other Editorial Revisions
DOE proposes the following editorial updates to improve the
readability of the test procedure and provide additional detail: (i)
Revising ``shall'' (and a single instance of ``should'' in the
temperature condition requirements at section 3.2.2(b)(3)) to ``must''
in appendix A, (ii) clarifying the instructional language for recording
the winding temperature for dry-type transformers (section 3.2.2 of
appendix A), (iii) separating certain sentences into enumerated clauses
(section 3.2.2(a) of appendix A),\19\ (iv) identifying the
corresponding resistance measurement method sections (section 3.3 of
appendix A), (v) replacing a reference to ``uniform test method'' with
``this Appendix'' (section 3.3 of appendix A), (vi) removing reference
to guidelines under section 3.4.1, Required actions, of appendix A to
clarify that section establishes requirements, (vii) specifying the
maximum amount of time for the temperature of the transformer windings
to stabilize (section 3.2.2(b)(4) of appendix A \20\), (viii) removing
references to the test procedure in 10 CFR 431.196, and (ix) replacing
any reference to accuracy requirements in ``section 2.0'' and/or
``Table 2.0'' to ``section 2.3'' and/or ``Table 2.3,'' accordingly.
---------------------------------------------------------------------------
\19\ Under the changes proposed in this document, section
3.2.2(a) of appendix A would be split into section 3.2.2(a) and
section 3.2.2(b).
\20\ Under the changes proposed in this document, this section
would become section 3.2.2(c)(4) of appendix A.
---------------------------------------------------------------------------
Section 3.2.2 of appendix A requires that, for testing of both
ventilated and sealed units, the ambient temperature of the test area
may be used to estimate the winding temperature (rather than direct
measurement of the winding temperature), provided a number of
conditions are met, including the condition that neither voltage nor
current has been applied to the unit under test for 24 hours (provided
in section 3.2.2(b)(4) of appendix A). The same section also allows for
the initial 24 hours to be increased to up to a maximum of an
additional 24 hours, so as to allow the temperature of the transformer
windings to stabilize at the level of the ambient temperature. Based on
the requirement, the total amount of time allowed would be a maximum of
48 hours. As such, in this NOPR, DOE proposes to specify explicitly
that, for section 3.2.2(b)(4) of appendix A, the total maximum amount
of time allowed is 48 hours.
DOE is also proposing conforming amendments to the energy
conservation standard provisions. 10 CFR 431.196 establishes energy
conservation standards for certain distribution transformers.
Immediately following each table of standards, a note specifies the
applicable test PUL and DOE test procedure. For example, in 10 CFR
431.196(a) the note reads, ``Note: All efficiency values are at 35
percent of nameplate-rated load, determined according to the DOE Test
Method for Measuring the Energy Consumption of Distribution
Transformers under Appendix A to Subpart K of 10 CFR part 431.''
Because 10 CFR 431.193 already requires that testing be in accordance
with appendix A, DOE proposes to remove the references to the test
procedure in 10 CFR 431.196. DOE proposes to maintain the portion of
the note identifying the PUL corresponding to the efficiency values,
for continuity and clarity.
As discussed in section III.J.1 and section III.J.2, DOE is
proposing to clarify the PUL and reference temperature specifications
for certification to energy conservation standards, and provide PUL and
reference temperature specifications for voluntary representations,
with a new section 2.1 for PUL requirements and section 2.2 for
reference temperature requirements in appendix A. Accordingly, DOE
proposes that the accuracy requirements previously provided in section
2.0 be moved to section 2.3 in appendix A. In addition, DOE proposes to
re-number Table 2.1, Test System Accuracy Requirements For Each
Measured Quantity, to Table 2.3. Lastly, DOE proposes to update cross-
[[Page 20721]]
references in appendix A to the accuracy requirements in section 2.0
and/or table 2.1, to section 2.3 and/or table 2.3. The cross-references
occur in section 3.1(b), section 3.3.3, section 3.4.2(a), section
4.3(a), section 6.0 and section 6.2 of appendix A.
K. Sampling, Representations, AEDMs
The certification and compliance requirements for distribution
transformers are codified at 10 CFR part 429. DOE's sampling
requirements are provided at 10 CFR 429.47. The sampling requirements,
among other things, state that, (1) the provisions of 10 CFR 429.11,
General sampling requirements for the selected units to be tested,
apply, (2) a manufacturer must use a sample of at least five units if
more than five units have been manufactured over a span of six months
(10 CFR 429.47(a)(2)(i)(A)), and (3) efficiency of a basic model may be
determined through testing, in accordance with appendix A, or through
application of an AEDM under the requirements of 10 CFR 429.70. (10 CFR
429.47(a)(2)(i)(B))
DOE's requirements related to AEDMs are at 10 CFR 429.70. This
section specifies under which circumstances an AEDM may be developed,
validated, and applied to performance ratings for certain covered
products and equipment.
In the September 2017 TP RFI, DOE requested feedback on the current
sampling requirements; on whether manufacturers typically represent the
minimum efficiency standard, the maximum efficiency allowable, or a
different value; and regarding the usefulness of the AEDM provisions.
82 FR 44347, 44351 (September 22, 2017) DOE received several comments
on the September 2017 TP RFI regarding these topics.
HVOLT commented that it believes the represented value calculations
are useful in describing tolerance and objectives; large volumes of
production have an easier means of achieving average performance than
very small volumes of transformers. (HVOLT, No. 3 at p. 29) NEMA
commented that the opportunity to use AEDM must be preserved, or burden
will be raised for some manufacturers, and that DOE should maintain the
status quo and afford manufacturers flexibility. (NEMA, No. 14 at p. 7)
Howard Industries also commented that it uses the AEDM method to the
fullest because it is too burdensome to physically test all units.
(Howard Industries, No. 24 at p. 2) DOE appreciates stakeholders'
comments and is not proposing changes to the AEDM provisions.
HVOLT stated that it believes all manufacturers test each
transformer manufactured for losses, and that normally distribution
transformers are overdesigned to minimize the possibility of non-
compliant designs. (HVOLT, No. 3 at p. 28) Suresh stated that for units
lower than 500 kVA, some manufacturers adopt bulk testing for a given
rating at a time, and the average efficiency is determined, and that in
some cases, manufacturers do not test all of their units because they
test a statistically significant number of units to demonstrate the
efficiency. (Suresh, No. 9 at p. 1) As discussed previously, DOE's
sampling requirements require that for ratings developed using testing
(rather than an AEDM) a manufacturer must use a sample of at least five
units if more than five units have been manufactured over a span of six
months (10 CFR 429.47(a)(2)(i)(B)), or as many as have been produced if
five or fewer have been manufactured over a span of six months (10 CFR
429.47(a)(2)(i)(A)).
NEMA recommended that DOE consider providing software for
manufacturers to help with reporting, and that this could be designed
to contain all the raw data and the represented efficiency
calculations. (NEMA, No. 14 at p. 8) DOE does provide product-specific
templates for certifying basic models, which can be found on the
following website: https://www.regulations.doe.gov/ccms/templates.
However, DOE does not provide software for certification reporting. It
is the manufacturer's responsibility to certify its products (or
equipment) as required by DOE under 10 CFR part 429. Further, the
manufacturer must decide how to represent the efficiency of a
transformer between the limits of the energy conservation standard and
the maximum representation allowed by 10 CFR 429.47(a)(2).
DOE received no other comments on the current sampling,
representation and AEDM requirements. DOE is not proposing amendments
to the sampling and AEDM requirements.
L. Test Procedure Costs, Harmonization, and Other Topics
1. Test Procedure Costs and Impact
EPCA requires that test procedures proposed by DOE not be unduly
burdensome to conduct. In this NOPR, DOE proposes to amend the existing
test procedure for distribution transformers by revising certain
definitions, incorporating new definitions, incorporating revisions
based on the latest versions of the IEEE industry standards, including
provisions to allow manufacturers to use the DOE test procedure to make
voluntary representations at additional PULs and/or reference
temperatures, and reorganizing content among relevant sections of the
CFR to improve readability. The proposed amendments would primarily
provide updates and supplemental details for how to conduct the test
procedure and do not add complexity to test conditions/setup or add
test steps. In accordance with EPCA, DOE has tentatively determined
that these proposed amendments would not be unduly burdensome for
manufacturers to conduct. Further, DOE has tentatively determined that
the proposal would not impact testing costs already experienced by
manufacturers. DOE estimates based on a test quote from a laboratory
that the cost for testing distribution transformers using the existing
test procedure is approximately $400 per unit tested and that this
figure would not change in response to the changes in this proposed
rule. In summary, the proposals reflect and codify current industry
practice.
The proposed amendments would not impact the scope of the test
procedure. The proposed amendments would not require the testing of
distribution transformers not already subject to the test procedure at
10 CFR 431.193 (i.e., the proposal would not require manufacturers to
test autotransformers, drive (isolation) transformers, grounding
transformers, machine-tool (control) transformers, nonventilated
transformers, rectifier transformers, regulating transformers, sealed
transformer; special-impedance transformer; testing transformer;
transformer with tap range of 20 percent or more; uninterruptible power
supply transformer; or welding transformer, which are presently not
subject to testing). The proposed amendments would not alter the
measured energy efficiency or energy use of the distribution
transformers. Manufacturers would be able to rely on data generated
under the current test procedure should the proposed amendments be
finalized. Further, the amendments proposed in this document, if
finalized, would not require the purchase of additional equipment for
testing.
DOE is proposing to adopt definitions for ``PUL,'' ``terminal'' and
``auxiliary device.'' The proposed definitions are intended to provide
additional specificity in the application of the test procedure. The
proposed definitions match current industry application of the test
procedure and, if finalized, would not impact the conduct of the test
or testing costs experienced by
[[Page 20722]]
manufacturers. DOE is also proposing to specify that both load loss and
no-load loss measurements must be made from ``terminal to terminal.''
Measuring losses at the transformer terminals reflects current industry
practices. In addition, the DOE test procedure already explicitly
requires certain measurements at the terminals; specifically, the
kelvin bridge method for determining resistance measurements in section
3.3.1.2(c), the voltmeter-ammeter method for determining resistance
measurements in section 3.3.2(c), and the no-load loss test method in
section 4.4.2(a)(3). Furthermore, taking other measurements (whose
measurement locations are not explicit in the test procedure) at
locations other than the terminal would yield results formed of
mutually incongruous components, and would leave unclear what the test
procedure was purporting to represent. Therefore, DOE initially
concludes that the proposal to specify that both load loss and no-load
loss measurements must be made from ``terminal to terminal'' reflects
current practice and would not add any additional testing cost.
DOE is proposing a number of updates to its test procedures based
on updates to the relevant IEEE standards. In addition to proposals
that reflect non-substantive editorial updates to the IEEE standards
(i.e., consistent use of the term ``insulating liquid''), DOE is
proposing to specify parameters for determining stability when making
resistance measurements, explicitly require the automatic recording of
data, specify the number of readings required for resistance
measurement, specify the connection locations for resistance
measurements, explicitly state the required test frequency, and require
the polarity of the core magnetization be kept constant during all
resistance readings. These proposed revisions, which are based on
updates to the IEEE standards, reflect industry consensus and current
practice. As such, these proposed revisions, if made final, would not
impact test costs.
DOE is proposing an amendment to the test procedures to permit
manufacturers to make voluntary representations of the performance
(i.e., efficiency, load loss, no load loss) of distribution
transformers at conditions other than those required for compliance
testing (i.e., at additional PULs and manufacturer selected reference
temperature). Under DOE's proposal in this document, manufacturers
would be permitted to make representations using the DOE test procedure
regarding the performance of distribution transformers under a wider
range of operating conditions. The additional representations would be
voluntary.
DOE estimates that if a manufacturer chose to make such voluntary
representations, no additional testing cost would be incurred because
the voluntary representations could be determined mathematically,
without any additional testing. As discussed previously, manufacturers
typically test distribution transformers at 100 percent PUL;
performance at other PULs (including the PULs required for compliance
with the energy conservation standards) is calculated mathematically.
Appendix A provides equations \21\ that manufacturers can use to (1)
calculate no-load and load losses at any reference temperature and (2)
calculate load losses at any PUL. These equations are currently used to
calculate performance at the DOE-required conditions, but these same
equations can also be used to calculate performance at additional
conditions (of PULs and reference temperatures) for any voluntary
representations, without the need to conduct additional testing.
---------------------------------------------------------------------------
\21\ Equations are provided in section 5.1, section 4.4.3.3, and
section 4.5.3.3 of appendix A.
---------------------------------------------------------------------------
A manufacturer could choose to re-test rather than mathematically
determine the values for voluntary representations at other PULs or
reference temperatures. However, the proposed provision regarding
voluntary representations does not necessitate additional testing, were
a manufacturer to choose to make voluntary representations. In
addition, DOE is not requiring any certification or reporting of
voluntary representations. For these reasons, no additional costs or
test burden would be incurred for voluntary representations.
In addition, DOE is also proposing to centralize the PUL and
reference temperature specifications in appendix A, both for the
certification to energy conservation standards and for use with a
voluntary representation. The updates are not substantive and do not
change existing test PUL requirements with respect to certification to
energy conservation standards. Rather, the consolidation would enhance
readability of the test procedure and more clearly communicate DOE's
PUL requirements with respect to certification to energy conservation
standards and voluntary representations.
The other proposed amendments are mainly clerical or editorial in
nature, and if finalized, they would not impact the measured test
results or impact the test costs.
DOE requests comment on its understanding of the impact and
associated costs of the proposed test procedure. To the extent
commenters believe that manufacturers would not be able to rely on data
generated under the current test procedure should the proposed
amendments be finalized, DOE requests comment on the potential
associated costs.
2. Harmonization With Industry Standards
As discussed in section III.D, the test procedure for distribution
transformers at appendix A mirrors language contained in several
industry standards: NEMA TP 2-1998; IEEE C57.12.90-1999; IEEE
C57.12.91-2001; IEEE C57.12.00-2000; and IEEE C57.12.01-1998. DOE notes
that when establishing the test procedure for distribution
transformers, DOE determined that basing the procedure on multiple
industry standards, as opposed to adopting an industry test procedure
(or procedures) without modification, was necessary to provide the
detail and accuracy required for the DOE test procedure, with the
additional benefit of providing manufacturers the DOE test procedure in
a single reference. As such, DOE relied heavily on the techniques and
methods from NEMA TP 2-1998, NEMA TP 2-2005 and the four IEEE standards
in developing the DOE test procedure. Both versions of NEMA TP 2
reference the IEEE standards as part of that industry test procedure.
Specifically, the IEEE standards provide the test system accuracy
requirements, resistance measurement test methods, and load loss and
no-load loss test methods for both NEMA TP 2-1998 and NEMA TP 2-2005.
Although both versions of NEMA TP 2 were designed to be a standard that
extracts and presents pertinent parts of the IEEE standards, DOE
determined the standard is not sufficiently clear and detailed to adopt
as the DOE test procedure. Therefore, the current DOE test procedure is
a stand-alone test procedure based on the multiple industry standards.
DOE seeks comment on the degree to which the DOE test procedure
should consider and be harmonized further with the most recent relevant
industry standards for distribution transformers, and whether any
changes to the Federal test method would provide additional benefits to
the public. DOE also requests comment on the benefits and burdens of
adopting any industry/voluntary consensus-based or other appropriate
test procedure, without modification.
[[Page 20723]]
3. Other Test Procedure Topics
In addition to the issues identified earlier in this document, DOE
welcomes comment on any other aspect of the existing test procedure for
distribution transformers not already addressed by the specific areas
identified in this document. DOE particularly seeks information that
would improve the representativeness of the test procedure, as well as
information that would help DOE create a procedure that would limit
manufacturer test burden. Comments regarding repeatability and
reproducibility are also welcome.
DOE also requests information that would help DOE create procedures
that would limit manufacturer test burden through streamlining or
simplifying testing requirements. In particular, DOE notes that under
Executive Order 13771, ``Reducing Regulation and Controlling Regulatory
Costs,'' Executive Branch agencies such as DOE must manage the costs
associated with the imposition of expenditures required to comply with
Federal regulations. See 82 FR 9339 (Feb. 3, 2017). Consistent with
that Executive Order, DOE encourages the public to provide input on
measures DOE could take to lower the cost of its regulations applicable
to distribution transformers consistent with the requirements of EPCA.
M. Compliance Date and Waivers
EPCA prescribes that all representations of energy efficiency and
energy use, including those made on marketing materials and product
labels, must be made in accordance with an amended test procedure,
beginning 180 days after publication of such a test procedure final
rule in the Federal Register. (42 U.S.C. 6314(d)(1)) If DOE were to
publish an amended test procedure, EPCA provides an allowance for
individual manufacturers to petition DOE for an extension of the 180-
day period if the manufacturer may experience undue hardship in meeting
the deadline. (42 U.S.C. 6314(d)(2)) To receive such an extension,
petitions must be filed with DOE no later than 60 days before the end
of the 180-day period and must detail how the manufacturer will
experience undue hardship. Id.
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
The Office of Management and Budget (OMB) has determined that test
procedure rulemakings do not constitute ``significant regulatory
actions'' under section 3(f) of Executive Order 12866, Regulatory
Planning and Review, 58 FR 51735 (Oct. 4, 1993). Accordingly, this
action was not subject to review under the Executive Order by the
Office of Information and Regulatory Affairs (OIRA) in the OMB.
B. Review Under Executive Orders 13771 and 13777
On January 30, 2017, the President issued Executive Order 13771,
``Reducing Regulation and Controlling Regulatory Costs.'' That Order
stated the policy of the executive branch is to be prudent and
financially responsible in the expenditure of funds, from both public
and private sources. The Order stated it is essential to manage the
costs associated with the governmental imposition of private
expenditures required to comply with Federal regulations. This
rulemaking is expected to be an E.O. 13771 other action because the
costs of this action is zero.
Additionally, on February 24, 2017, the President issued Executive
Order 13777, ``Enforcing the Regulatory Reform Agenda.'' The Order
required the head of each agency designate an agency official as its
Regulatory Reform Officer (RRO). Each RRO oversees the implementation
of regulatory reform initiatives and policies to ensure that agencies
effectively carry out regulatory reforms, consistent with applicable
law. Further, E.O. 13777 requires the establishment of a regulatory
task force at each agency. The regulatory task force is required to
make recommendations to the agency head regarding the repeal,
replacement, or modification of existing regulations, consistent with
applicable law. At a minimum, each regulatory reform task force must
attempt to identify regulations that:
(i) Eliminate jobs, or inhibit job creation;
(ii) Are outdated, unnecessary, or ineffective;
(iii) Impose costs that exceed benefits;
(iv) Create a serious inconsistency or otherwise interfere with
regulatory reform initiatives and policies;
(v) Are inconsistent with the requirements of Information Quality
Act, or the guidance issued pursuant to that Act, in particular those
regulations that rely in whole or in part on data, information, or
methods that are not publicly available or that are insufficiently
transparent to meet the standard for reproducibility; or
(vi) Derive from or implement Executive Orders or other
Presidential directives that have been subsequently rescinded or
substantially modified.
DOE initially concludes that this rulemaking is consistent with the
directives set forth in these executive orders. The proposed rule would
not yield any costs or cost savings.
C. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires
preparation of an initial regulatory flexibility analysis (IFRA) for
any rule that by law must be proposed for public comment, unless the
agency certifies that the rule, if promulgated, will not have a
significant economic impact on a substantial number of small entities.
As required by Executive Order 13272, ``Proper Consideration of Small
Entities in Agency Rulemaking,'' 67 FR 53461 (August 16, 2002), DOE
published procedures and policies on February 19, 2003, to ensure that
the potential impacts of its rules on small entities are properly
considered during the DOE rulemaking process. 68 FR 7990. DOE has made
its procedures and policies available on the Office of the General
Counsel's website: http://energy.gov/gc/office-general-counsel.
DOE reviewed the test procedures considered in this proposed rule
to amend the test procedure for distribution transformers under the
provisions of the Regulatory Flexibility Act and the procedures and
policies published on February 19, 2003.
The Small Business Administration (``SBA'') considers a business
entity to be a small business, if, together with its affiliates, it
employs less than a threshold number of workers specified in 13 CFR
part 121. The size standards and codes are established by the 2017
North American Industry Classification System (``NAICS'').
Distribution transformers manufacturers are classified under NAICS
code 335311, power, distribution, and specialty transformer
manufacturing. The SBA sets a threshold of 750 employees or fewer for
an entity to be considered as a small business.\22\ DOE conducted a
focused inquiry into small business manufacturers of equipment covered
by this rulemaking. DOE used its publicly available Compliance
Certification Database \23\ to create a list of companies that import
or otherwise manufacture distribution transformers covered by this
rulemaking. Using these sources, DOE identified a total of 21 distinct
manufacturers of distribution transformers.
---------------------------------------------------------------------------
\22\ https://www.sba.gov/document/support--table-size-standards.
\23\ https://www.regulations.doe.gov/certification-data.
---------------------------------------------------------------------------
DOE then reviewed these data to determine whether the entities met
the
[[Page 20724]]
SBA's definition of ``small business'' as it relates to NAICS code
335311 and to screen out companies that do not offer equipment covered
by this rulemaking, do not meet the definition of a ``small business,''
or are foreign owned and operated. Based on this review, DOE has
identified 10 manufacturers that are potential small businesses.
Through this analysis, DOE has determined the expected effects of the
proposed rule on these covered small businesses and whether an IRFA was
needed (i.e., whether DOE could certify that this rulemaking would not
have a significant impact).
The proposed requirements of this NOPR neither expand the scope of
equipment currently subject to test procedures, nor do they place
additional requirements on distribution transformers currently subject
to test procedures. In addition, the proposed amendments would not
alter the measured energy efficiency/energy use of the distribution
transformers. Manufacturers would be able to rely on data generated
under the current test procedure should the proposed amendments be
finalized. Therefore, no proposed revisions would increase burden on
manufacturers.
However, in the NOPR, DOE is proposing to allow manufacturers to
make voluntary representations of the performance of distribution
transformers at conditions other than those required currently for
compliance testing. DOE estimates that, if a manufacturer chose to make
such representations, no additional testing cost would be incurred
because the voluntary representations could be determined
mathematically and without any additional testing required. Therefore,
DOE concludes that no incremental testing cost and no additional
testing burden would be incurred by manufacturers because of this
proposed rule.
Given that the proposed test procedures would not increase burden
on small manufacturers, DOE certifies that the proposed testing
procedure amendments would not have a ``significant economic impact on
a substantial number of small entities,'' and the preparation of an
IRFA is not warranted. DOE will submit a certification and supporting
statement of factual basis to the Chief Counsel for Advocacy of the
Small Business Administration for review under 5 U.S.C. 605(b).
DOE seeks comment on whether the proposed test procedure changes
would place new and significant burdens on a substantial number of
small entities.
D. Review Under the Paperwork Reduction Act of 1995
Manufacturers of distribution transformers must certify to DOE that
their products comply with any applicable energy conservation
standards. To certify compliance, manufacturers must first obtain test
data for their products according to the DOE test procedures, including
any amendments adopted for those test procedures. DOE has established
regulations for the certification and recordkeeping requirements for
all covered consumer products and commercial equipment, including
distribution transformers. (See generally 10 CFR part 429.) The
collection-of-information requirement for the certification and
recordkeeping is subject to review and approval by OMB under the
Paperwork Reduction Act (PRA). This requirement has been approved by
OMB under OMB control number 1910-1400. Public reporting burden for the
certification is estimated to average 35 hours per response, including
the time for reviewing instructions, searching existing data sources,
gathering and maintaining the data needed, and completing and reviewing
the collection of information.
Notwithstanding any other provision of the law, no person is
required to respond to, nor shall any person be subject to a penalty
for failure to comply with, a collection of information subject to the
requirements of the PRA, unless that collection of information displays
a currently valid OMB Control Number.
E. Review Under the Treasury and General Government Appropriations Act,
1999
Section 654 of the Treasury and General Government Appropriations
Act, 1999 (Pub. L. 105-277) requires Federal agencies to issue a Family
Policymaking Assessment for any rule that may affect family well-being.
This proposed rule would not have any impact on the autonomy or
integrity of the family as an institution. Accordingly, DOE has
concluded that it is not necessary to prepare a Family Policymaking
Assessment.
F. Review Under the National Environmental Policy Act of 1969
In this proposed rule, DOE proposes test procedure amendments that
it expects will be used to develop and implement future energy
conservation standards for distribution transformers. DOE has
determined that this rule falls into a class of actions that are
categorically excluded from review under the National Environmental
Policy Act of 1969 (42 U.S.C. 4321 et seq.) and DOE's implementing
regulations at 10 CFR part 1021. Specifically, this proposed rule would
amend the existing test procedures without affecting the amount,
quality or distribution of energy usage, and, therefore, would not
result in any environmental impacts. Thus, this rulemaking is covered
by Categorical Exclusion A5 under 10 CFR part 1021, subpart D, which
applies to any rulemaking that interprets or amends an existing rule
without changing the environmental effect of that rule. Accordingly,
neither an environmental assessment nor an environmental impact
statement is required.
G. Review Under Executive Order 13132
Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 4, 1999)
imposes certain requirements on agencies formulating and implementing
policies or regulations that preempt State law or that have Federalism
implications. The Executive Order requires agencies to examine the
constitutional and statutory authority supporting any action that would
limit the policymaking discretion of the States and to carefully assess
the necessity for such actions. The Executive Order also requires
agencies to have an accountable process to ensure meaningful and timely
input by State and local officials in the development of regulatory
policies that have Federalism implications. On March 14, 2000, DOE
published a statement of policy describing the intergovernmental
consultation process it will follow in the development of such
regulations. 65 FR 13735. DOE has examined this proposed rule and has
determined that it would not have a substantial direct effect on the
States, on the relationship between the national government and the
States, or on the distribution of power and responsibilities among the
various levels of government. EPCA governs and prescribes Federal
preemption of State regulations as to energy conservation for the
products that are the subject of this proposed rule. States can
petition DOE for exemption from such preemption to the extent, and
based on criteria, set forth in EPCA. (42 U.S.C. 6297(d)) No further
action is required by Executive Order 13132.
H. Review Under Executive Order 12988
Regarding the review of existing regulations and the promulgation
of new regulations, section 3(a) of Executive Order 12988, ``Civil
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal
agencies the general duty to adhere to the following
[[Page 20725]]
requirements: (1) Eliminate drafting errors and ambiguity, (2) write
regulations to minimize litigation, (3) provide a clear legal standard
for affected conduct rather than a general standard, and (4) promote
simplification and burden reduction. Section 3(b) of Executive Order
12988 specifically requires that Executive agencies make every
reasonable effort to ensure that the regulation (1) clearly specifies
the preemptive effect, if any, (2) clearly specifies any effect on
existing Federal law or regulation, (3) provides a clear legal standard
for affected conduct while promoting simplification and burden
reduction, (4) specifies the retroactive effect, if any, (5) adequately
defines key terms, and (6) addresses other important issues affecting
clarity and general draftsmanship under any guidelines issued by the
Attorney General. Section 3(c) of Executive Order 12988 requires
Executive agencies to review regulations in light of applicable
standards in sections 3(a) and 3(b) to determine whether they are met
or it is unreasonable to meet one or more of them. DOE has completed
the required review and determined that, to the extent permitted by
law, the proposed rule meets the relevant standards of Executive Order
12988.
I. Review Under the Unfunded Mandates Reform Act of 1995
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA)
requires each Federal agency to assess the effects of Federal
regulatory actions on State, local, and Tribal governments and the
private sector. Public Law 104-4, sec. 201 (codified at 2 U.S.C. 1531).
For a proposed regulatory action likely to result in a rule that may
cause the expenditure by State, local, and Tribal governments, in the
aggregate, or by the private sector of $100 million or more in any one
year (adjusted annually for inflation), section 202 of UMRA requires a
Federal agency to publish a written statement that estimates the
resulting costs, benefits, and other effects on the national economy.
(2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal agency to
develop an effective process to permit timely input by elected officers
of State, local, and Tribal governments on a proposed ``significant
intergovernmental mandate,'' and requires an agency plan for giving
notice and opportunity for timely input to potentially affected small
governments before establishing any requirements that might
significantly or uniquely affect small governments. On March 18, 1997,
DOE published a statement of policy on its process for
intergovernmental consultation under UMRA. 62 FR 12820; also available
at http://energy.gov/gc/office-general-counsel. DOE examined this
proposed rule according to UMRA and its statement of policy and
determined that the rule contains neither an intergovernmental mandate,
nor a mandate that may result in the expenditure of $100 million or
more in any year, so these requirements do not apply.
J. Review Under Executive Order 12630
DOE has determined, under Executive Order 12630, ``Governmental
Actions and Interference with Constitutionally Protected Property
Rights'' 53 FR 8859 (March 18, 1988) that this regulation would not
result in any takings that might require compensation under the Fifth
Amendment to the U.S. Constitution.
K. Review Under Treasury and General Government Appropriations Act,
2001
Section 515 of the Treasury and General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note) provides for agencies to review most
disseminations of information to the public under guidelines
established by each agency pursuant to general guidelines issued by
OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 2002), and
DOE's guidelines were published at 67 FR 62446 (Oct. 7, 2002). DOE has
reviewed this proposed rule under the OMB and DOE guidelines and has
concluded that it is consistent with applicable policies in those
guidelines.
L. Review Under Executive Order 13211
Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355
(May 22, 2001), requires Federal agencies to prepare and submit to OMB,
a Statement of Energy Effects for any proposed significant energy
action. A ``significant energy action'' is defined as any action by an
agency that promulgated or is expected to lead to promulgation of a
final rule, and that (1) is a significant regulatory action under
Executive Order 12866, or any successor order; and (2) is likely to
have a significant adverse effect on the supply, distribution, or use
of energy; or (3) is designated by the Administrator of OIRA as a
significant energy action. For any proposed significant energy action,
the agency must give a detailed statement of any adverse effects on
energy supply, distribution, or use should the proposal be implemented,
and of reasonable alternatives to the action and their expected
benefits on energy supply, distribution, and use.
The proposed regulatory action to amend the test procedure for
measuring the energy efficiency of distribution transformers is not a
significant regulatory action under Executive Order 12866. Moreover, it
would not have a significant adverse effect on the supply,
distribution, or use of energy, nor has it been designated as a
significant energy action by the Administrator of OIRA. Therefore, it
is not a significant energy action, and, accordingly, DOE has not
prepared a Statement of Energy Effects.
M. Review Under Section 32 of the Federal Energy Administration Act of
1974
Under section 301 of the Department of Energy Organization Act
(Pub. L. 95-91; 42 U.S.C. 7101), DOE must comply with section 32 of the
Federal Energy Administration Act of 1974, as amended by the Federal
Energy Administration Authorization Act of 1977. (15 U.S.C. 788; FEAA)
Section 32 essentially provides in relevant part that, where a proposed
rule authorizes or requires use of commercial standards, the notice of
proposed rulemaking must inform the public of the use and background of
such standards. In addition, section 32(c) requires DOE to consult with
the Attorney General and the Chairman of the Federal Trade Commission
(FTC) concerning the impact of the commercial or industry standards on
competition.
The proposed modifications to the test procedure for distribution
transformers in this NOPR do not incorporate by reference any
commercial testing standards. Therefore, the requirements of section
32(b) of the FEAA do not apply.
N. Referenced Consensus Standards
In this NOPR, DOE does not propose to incorporate by reference any
industry test standards. Rather, DOE proposes that the test procedure
continue to be stand-alone, and be based on NEMA TP 2-1998 and NEMA TP
2-2005, and the latest versions of the IEEE standards, IEEE C57.12.90-
2015, IEEE C57.12.91-2011, IEEE C57.12.00-2015, and IEEE C57.12.01-
2015.
V. Public Participation
A. Submission of Comments
DOE will accept comments, data, and information regarding this
proposed rule no later than the date provided in the DATES section at
the beginning of this proposed rule. Interested parties may submit
comments using any of the methods described in the ADDRESSES section at
the beginning of this notice.
[[Page 20726]]
Submitting comments via http://www.regulations.gov. The http://www.regulations.gov web page will require you to provide your name and
contact information. Your contact information will be viewable to DOE
Building Technologies staff only. Your contact information will not be
publicly viewable except for your first and last names, organization
name (if any), and submitter representative name (if any). If your
comment is not processed properly because of technical difficulties,
DOE will use this information to contact you. If DOE cannot read your
comment due to technical difficulties and cannot contact you for
clarification, DOE may not be able to consider your comment.
However, your contact information will be publicly viewable if you
include it in the comment itself or in any documents attached to your
comment. Any information that you do not want to be publicly viewable
should not be included in your comment, nor in any document attached to
your comment. Otherwise, persons viewing comments will see only first
and last names, organization names, correspondence containing comments,
and any documents submitted with the comments.
Do not submit to http://www.regulations.gov information for which
disclosure is restricted by statute, such as trade secrets and
commercial or financial information (hereinafter referred to as
Confidential Business Information (CBI)). Comments submitted through
http://www.regulations.gov cannot be claimed as CBI. Comments received
through the website will waive any CBI claims for the information
submitted. For information on submitting CBI, see the Confidential
Business Information section.
DOE processes submissions made through http://www.regulations.gov
before posting. Normally, comments will be posted within a few days of
being submitted. However, if large volumes of comments are being
processed simultaneously, your comment may not be viewable for up to
several weeks. Please keep the comment tracking number that http://www.regulations.gov provides after you have successfully uploaded your
comment.
Submitting comments via email, hand delivery/courier, or mail.
Comments and documents submitted via email, hand delivery/courier, or
mail also will be posted to http://www.regulations.gov. If you do not
want your personal contact information to be publicly viewable, do not
include it in your comment or any accompanying documents. Instead,
provide your contact information in a cover letter. Include your first
and last names, email address, telephone number, and optional mailing
address. The cover letter will not be publicly viewable as long as it
does not include any comments.
Include contact information each time you submit comments, data,
documents, and other information to DOE. If you submit via mail or hand
delivery/courier, please provide all items on a CD, if feasible, in
which case it is not necessary to submit printed copies. No
telefacsimiles (faxes) will be accepted.
Comments, data, and other information submitted to DOE
electronically should be provided in PDF (preferred), Microsoft Word or
Excel, WordPerfect, or text (ASCII) file format. Provide documents that
are not secured, that are written in English, and that are free of any
defects or viruses. Documents should not contain special characters or
any form of encryption and, if possible, they should carry the
electronic signature of the author.
Campaign form letters. Please submit campaign form letters by the
originating organization in batches of between 50 to 500 form letters
per PDF or as one form letter with a list of supporters' names compiled
into one or more PDFs. This reduces comment processing and posting
time.
Confidential Business Information. Pursuant to 10 CFR 1004.11, any
person submitting information that he or she believes to be
confidential and exempt by law from public disclosure should submit via
email, postal mail, or hand delivery/courier two well-marked copies:
One copy of the document marked ``confidential'' including all the
information believed to be confidential, and one copy of the document
marked ``non-confidential'' with the information believed to be
confidential deleted. Submit these documents via email or on a CD, if
feasible. DOE will make its own determination about the confidential
status of the information and treat it according to its determination.
Factors of interest to DOE when evaluating requests to treat
submitted information as confidential include (1) a description of the
items, (2) whether and why such items are customarily treated as
confidential within the industry, (3) whether the information is
generally known by or available from other sources, (4) whether the
information has previously been made available to others without
obligation concerning its confidentiality, (5) an explanation of the
competitive injury to the submitting person that would result from
public disclosure, (6) when such information might lose its
confidential character due to the passage of time, and (7) why
disclosure of the information would be contrary to the public interest.
It is DOE's policy that all comments may be included in the public
docket, without change and as received, including any personal
information provided in the comments (except information deemed to be
exempt from public disclosure).
DOE considers public participation to be a very important part of
the process for developing test procedures and energy conservation
standards. DOE actively encourages the participation and interaction of
the public during the comment period in each stage of this process.
Interactions with and between members of the public provide a balanced
discussion of the issues and assist DOE in the process. Anyone who
wishes to be added to the DOE mailing list to receive future notices
and information about this process should contact Appliance and
Equipment Standards Program staff at (202) 586-6636 or via email at
[email protected].
B. Issues on Which DOE Seeks Comment
Although DOE welcomes comments on any aspect of this proposal, DOE
is particularly interested in receiving comments and views of
interested parties concerning the following issues:
(1.) DOE requests comment on: (1) Whether the current definition of
rectifier transformer is sufficiently specific, (2) if not, what
modifications would make it sufficiently specific, and (3) whether
partial output phase shift, harmonic current tolerance, or other
electrical properties may be used to reliably identify rectifier
transformers.
(2.) DOE requests comment on: (1) Whether the current definition of
drive transformer is sufficiently specific, (2) if not, what
modifications would make it sufficiently specific, and (3) the level of
technical similarity drive transformers bear to rectifier transformers.
(3.) DOE requests comment on its proposed definition of ``per-unit
load'' and its proposal to consolidate the usage of various terms
referring to less-than-full rated load to the single term ``per-unit
load.''
(4.) DOE requests comment on its proposed definition of
``terminal.''
(5.) DOE requests comment on its proposed definition of ``auxiliary
device,'' and whether certain components should be added or removed
from the listed auxiliary devices and why. DOE also requests comment on
whether it is appropriate to include functional component
[[Page 20727]]
designations as part of a definition of ``auxiliary device'' and, if
so, which functions and why.
(6.) DOE requests comment on its proposed updated definition of
``low-voltage dry-type distribution transformer.''
(7.) DOE requests comment on its proposed updated definition of
``reference temperature.''
(8.) DOE requests comment on the proposed updates based on the
latest version of the applicable IEEE standards for testing
distribution transformers, and specifically regarding whether industry
is already testing to the requirements of those IEEE standards.
(9.) DOE requests comment on the tentative determination that each
of the proposals do not increase test cost or burden, and that they
would not result in different measured values than the current test
procedure.
(10.) DOE requests comment on the proposal to amend the DOE test
procedure to permit manufacturers to make voluntary representations at
any additional PUL and/or reference temperature, and whether this would
assist consumers in making better purchasing decisions based on their
specific installation conditions. DOE requests comment on whether the
current DOE test procedure would be appropriate at non-mandatory PULs
and reference temperatures.
(11.) DOE requests comment on secondary winding configurations. DOE
also requests comment on the magnitude of the additional losses
associated with the less efficient configurations as well as the
relative period of operation in each winding configuration.
(12.) DOE requests comments regarding when, or at what number of
time constants, stability is reached for the voltmeter-ammeter method
and the resistance bridge method.
(13.) DOE seeks comment on its proposal to maintain the laboratory
ambient and transformer internal temperature requirements with no
changes.
(14.) DOE seeks comment on its proposal to modify section 4.1 of
appendix A to read ``. . .Test all distribution transformers using a
sinusoidal waveform (k=1).''
(15.) DOE requests comment on its understanding of the impact and
associated costs of the proposed test procedure. To the extent
commenters believe that manufacturers would not be able to rely on data
generated under the current test procedure should the proposed
amendments be finalized, DOE requests comment on the potential
associated costs.
(16.) DOE seeks comment on the degree to which the DOE test
procedure should consider and be harmonized further with the most
recent relevant industry standards for distribution transformers, and
whether any changes to the Federal test method would provide additional
benefits to the public. DOE also requests comment on the benefits and
burdens of adopting any industry/voluntary consensus-based or other
appropriate test procedure, without modification.
(17.) DOE seeks comment on whether the proposed test procedure
changes would place new and significant burdens on a substantial number
of small entities.
VI. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this proposed
rule.
List of Subjects in 10 CFR Part 431
Administrative practice and procedure, Confidential business
information, Energy conservation test procedures, Incorporation by
reference, and Reporting and recordkeeping requirements.
Signed in Washington, DC, on April 23, 2019.
Steven Chalk,
Acting Deputy Assistant Secretary for Energy Efficiency, Energy
Efficiency and Renewable Energy.
For the reasons stated in the preamble, DOE is proposing to amend
part 431 of Chapter II of Title 10, Code of Federal Regulations as set
forth below:
PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND
INDUSTRIAL EQUIPMENT
0
1. The authority citation for part 431 continues to read as follows:
Authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note.
0
2. Section 431.192 is amended by revising the definitions of Low-
voltage dry-type distribution transformer and Reference temperature,
and adding in alphabetical order, definitions for Auxiliary device,
Per-unit load, and Terminal, to read as follows:
Sec. 431.192 Definitions.
* * * * *
Auxiliary device means a localized component of a distribution
transformer that is a circuit breaker, switch, fuse, or surge/lightning
arrester.
* * * * *
Low-voltage dry-type distribution transformer means a distribution
transformer that--
(1) Has an input voltage of 600 volts or less;
(2) Is air-cooled; and
(3) Does not use insulating liquid as a coolant.
* * * * *
Per-unit load means the fraction of rated load.
* * * * *
Reference temperature means the temperature at which the
transformer losses are determined, and to which such losses are
corrected if testing is done at a different point. (Reference
temperature values are specified in the test method in appendix A to
this subpart.)
* * * * *
Terminal means a conducting element of a distribution transformer
providing electrical connection to an external conductor that is not
part of the transformer.
* * * * *
0
3. Section 431.193 is revised to read as follows:
Sec. 431.193 Test procedures for measuring energy consumption of
distribution transformers.
The test procedures for measuring the energy efficiency of
distribution transformers for purposes of EPCA are specified in
appendix A to this subpart. The test procedures specified in appendix A
to this subpart apply only to distribution transformers subject to
energy conservation standards at Sec. 431.196.
0
4. Section 431.196 is amended by revising the Notes in paragraphs
(a)(1), (a)(2), (b)(1), (b)(2), (c)(1), and (c)(2), to read as follows:
Sec. 431.196 Energy conservation standards and their effective
dates.
(a) * * *
(1) * * *
Note: All efficiency values are at 35 percent per-unit load.
(2) * * *
Note: All efficiency values are at 35 percent per-unit load.
(b) * * *
(1) * * *
Note: All efficiency values are at 50 percent per-unit load.
(2) * * *
Note: All efficiency values are at 50 percent per-unit load.
(c) * * *
(1) * * *
Note: All efficiency values are at 50 percent per-unit load.
[[Page 20728]]
(2) * * *
Note: All efficiency values are at 50 percent per-unit load.
* * * * *
0
5. Appendix A to subpart K of part 431 is amended by:
0
a. Revising section 2.0;
0
b. Adding sections 2.1, 2.2, and 2.3;
0
c. Revising paragraph (b) and adding paragraph (c) in section 3.1;
0
d. Revising section 3.2.1.1;
0
e. Revising paragraph (b) of section 3.2.1.2;
0
f. Revising section 3.2.2;
0
g. Revising section 3.3;
0
h. Revising paragraphs (a) introductory text and paragraph (b) in
section 3.3.2;
0
i. Revising section 3.3.3;
0
j. Revising the introductory text and adding paragraphs (f), (g), (h),
and (i) in section 3.4.1;
0
k. Revising paragraph (a) in section 3.4.2;
0
l. Revising paragraph (a) in section 3.5;
0
m. Revising section 4.1;
0
n. Revising paragraph (a) and adding paragraph (c) in section 4.3;
0
o. Revising paragraph (b) and the note following the paragraph in
section 4.4.2;
0
p. Revising section 4.4.3.3;
0
q. Revising section 5.1;
0
r. Revising section 6.0;
0
s. Revising section 6.1;
0
t. Revising paragraph (a) of section 6.2; and
0
u. Adding section 7.0.
The additions and revisions read as follows:
Appendix A to Subpart K of Part 431--Uniform Test Method for Measuring
the Energy Consumption of Distribution Transformers
* * * * *
2.0 Per-Unit Load, Reference Temperature, and Accuracy Requirements
2.1 Per-unit Load
In conducting the test procedure in this Appendix for the
purpose of:
(a) Certification to an energy conservation standard, the
applicable per-unit load in Table 2.1 must be used; or
(b) Making voluntary representations as provided in section 7.0
at an additional per-unit load, select the per-unit load of
interest.
Table 2.1--Per-Unit Load for Certification to Energy Conservation
Standards
------------------------------------------------------------------------
Per-unit
Distribution transformer category load
(percent)
------------------------------------------------------------------------
Liquid-immersed............................................. 50
Medium-voltage dry-type..................................... 50
Low-voltage dry-type........................................ 35
------------------------------------------------------------------------
2.2 Reference Temperature
In conducting the test procedure in this Appendix for the
purpose of:
(a) Certification to an energy conservation standard, the
applicable reference temperature in Table 2.2 must be used; or
(b) Making voluntary representations as provided in section 7.0
at an additional reference temperature, select the reference
temperature of interest.
Table 2.2--Reference Temperature for Certification to Energy
Conservation Standards
------------------------------------------------------------------------
Distribution transformer category Reference temperature
------------------------------------------------------------------------
Liquid-immersed........................... 20 [deg]C for no-load loss.
55 [deg]C for load loss.
Medium-voltage dry-type................... 20 [deg]C for no-load loss.
75 [deg]C for load loss.
Low-voltage dry-type...................... 20 [deg]C for no-load loss.
75 [deg]C for load loss.
------------------------------------------------------------------------
2.3 Accuracy Requirements
(a) Equipment and methods for loss measurement must be
sufficiently accurate that measurement error will be limited to the
values shown in Table 2.3.
Table 2.3--Test System Accuracy Requirements for Each Measured Quantity
------------------------------------------------------------------------
Measured quantity Test system accuracy
------------------------------------------------------------------------
Power Losses......................... 3.0%.
Voltage.............................. 0.5%.
Current.............................. 0.5%.
Resistance........................... 0.5%.
Temperature.......................... 1.5 [deg]C for liquid-
immersed distribution
transformers, and 2.0 [deg]C for low-voltage
dry-type and medium-voltage dry-
type distribution transformers.
------------------------------------------------------------------------
(b) Only instrument transformers meeting the 0.3 metering
accuracy class, or better, may be used under this test method.
3.0 * * *
3.1 General Considerations
* * * * *
(b) Measure the direct current resistance (Rdc) of
transformer windings by one of the methods outlined in section 3.3.
The methods of section 3.5 must be used to correct load losses to
the applicable reference temperature from the temperature at which
they are measured. Observe precautions while taking measurements,
such as those in section 3.4, in order to maintain measurement
uncertainty limits specified in Table 2.3.
(c) Measure resistance with the transformer energized by a 60 Hz
supply.
* * * * *
3.2.1.1 Methods
Record the winding temperature (Tdc) of liquid-
immersed transformers as the average of either of the following:
(a) The measurements from two temperature sensing devices (for
example, thermocouples) applied to the outside of the transformer
tank and thermally insulated from the surrounding environment, with
one located at the level of the insulating liquid and the other
located near the tank bottom or at the lower radiator header if
applicable; or
(b) The measurements from two temperature sensing devices
immersed in the insulating liquid, with one located directly above
the winding and other located directly below the winding.
3.2.1.2 Conditions
* * * * *
(b) The temperature of the insulating liquid has stabilized, and
the difference between the top and bottom temperature does not
exceed 5 [deg]C. The temperature of the insulating liquid is
considered stable if the top liquid temperature does not vary more
than 2 [deg]C in a 1-h period.
3.2.2 Dry-Type Distribution Transformers
Record the winding temperature (Tdc) of dry-type
transformers as one of the following:
(a) For ventilated dry-type units, use the average of readings
of four or more thermometers, thermocouples, or other suitable
temperature sensors inserted within the coils. Place the sensing
points of the measuring devices as close as possible to the winding
conductors; or
(b) For sealed units, such as epoxy-coated or epoxy-encapsulated
units, use the average of four or more temperature sensors located
on the enclosure and/or cover, as close to different parts of the
winding assemblies as possible; or
(c) For ventilated units or sealed units, use the ambient
temperature of the test area, only if the following conditions are
met:
(1) All internal temperatures measured by the internal
temperature sensors must not differ from the test area ambient
temperature by more than 2 [deg]C.
Enclosure surface temperatures for sealed units must not differ
from the test area ambient temperature by more than 2 [deg]C.
(2) Test area ambient temperature must not have changed by more
than 3 [deg]C for 3 hours before the test.
(3) Neither voltage nor current has been applied to the unit
under test for 24 hours. In addition, increase this initial 24-hour
period by any added amount of time necessary for the temperature of
the transformer windings to stabilize at the level of the ambient
temperature. However, this additional amount of time need not exceed
24 hours (i.e., after 48 hours, the transformer windings can be
assumed to have stabilized at the level of the ambient temperature.
Any stabilization time beyond 48 hours is optional).
[[Page 20729]]
3.3 Resistance Measurement Methods
Make resistance measurements using either the resistance bridge
method (section 3.3.1), the voltmeter-ammeter method (section 3.3.2)
or resistance meters (section 3.3.3). In each instance when this
Appendix is used to test more than one unit of a basic model to
determine the efficiency of that basic model, the resistance of the
units being tested may be determined from making resistance
measurements on only one of the units.
* * * * *
3.3.2 Voltmeter-Ammeter Method
(a) Employ the voltmeter-ammeter method only if the test current
is limited to 15 percent of the winding current. Connect the
transformer winding under test to the circuit shown in Figure 3.3. *
* *
(b) To perform the measurement, turn on the source to produce
current no larger than 15 percent of the rated current for the
winding. Wait until the current and voltage readings have stabilized
and then take a minimum of four readings of voltage and current.
Voltage and current readings must be taken simultaneously for each
of the readings. Calculate the average voltage and average current
using the readings. Determine the winding resistance Rdc
by using equation 3-4 as follows:
[GRAPHIC] [TIFF OMITTED] TP10MY19.000
Where:
Vmdc is the average voltage measured by the voltmeter V,
and
Imdc is the average current measured by the ammeter (A).
* * * * *
3.3.3 Resistance Meters
Resistance meters may be based on voltmeter-ammeter, or
resistance bridge, or some other operating principle. Any meter used
to measure a transformer's winding resistance must have
specifications for resistance range, current range, and ability to
measure highly inductive resistors that cover the characteristics of
the transformer being tested. Also, the meter's specifications for
accuracy must meet the applicable criteria of Table 2.3 in section
2.3.
* * * * *
3.4.1 Required Actions
The following requirements must be observed when making
resistance measurements:
* * * * *
(f) Keep the polarity of the core magnetization constant during
all resistance measurements.
(g) For single-phase windings, measure the resistance from
terminal to terminal. The total winding resistance is the terminal-
to-terminal measurement. For series-parallel windings, the total
winding resistance is the sum of the series terminal-to-terminal
section measurements.
(h) For wye windings, measure the resistance from terminal to
terminal or from terminal to neutral. For the total winding
resistance, the resistance of the lead from the neutral connection
to the neutral bushing may be excluded. For terminal-to-terminal
measurements, the total resistance reported is the sum of the three
measurements divided by two.
(i) For delta windings, measure resistance from terminal to
terminal with the delta closed or from terminal to terminal with the
delta open to obtain the individual phase readings. The total
winding resistance is the sum of the three-phase readings if the
delta is open. If the delta is closed, the total winding resistance
is the sum of the three phase-to-phase readings times 1.5.
3.4.2 Guideline for Time Constant
(a) The following guideline is suggested for the tester as a
means to facilitate the measurement of resistance in accordance with
the accuracy requirements of section 2.3:
* * * * *
3.5 Conversion of Resistance Measurements
(a) Resistance measurements must be corrected from the
temperature at which the winding resistance measurements were made,
to the reference temperature.
* * * * *
4.0 * * *
4.1 General Considerations
The efficiency of a transformer is computed from the total
transformer losses, which are determined from the measured value of
the no-load loss and load loss power components. Each of these two
power loss components is measured separately using test sets that
are identical, except that shorting straps are added for the load-
loss test. The measured quantities need correction for
instrumentation losses and may need corrections for known phase
angle errors in measuring equipment and for the waveform distortion
in the test voltage. Any power loss not measured at the applicable
reference temperature must be adjusted to that reference
temperature. The measured load loss must also be adjusted to a
specified output loading level if not measured at the specified
output loading level. Test all distribution transformers using a
sinusoidal waveform (k=1). Measure losses with the transformer
energized by a 60 Hz supply.
* * * * *
4.3 Test Sets
(a) The same test set may be used for both the no-load loss and
load loss measurements provided the range of the test set
encompasses the test requirements of both tests. Calibrate the test
set to national standards to meet the tolerances in Table 2.3 in
section 2.3. In addition, the wattmeter, current measuring system
and voltage measuring system must be calibrated separately if the
overall test set calibration is outside the tolerance as specified
in section 2.3 or the individual phase angle error exceeds the
values specified in section 4.5.3.
* * * * *
(c) Both load loss and no-load loss measurements must be made
from terminal to terminal.
* * * * *
4.4.2 No-Load Loss Test
* * * * *
(b) Adjust the voltage to the specified value as indicated by
the average-sensing voltmeter. Automatically and simultaneously
record the values of rms voltage, rms current, electrical power, and
average voltage using a digital data acquisition system. For a
three-phase transformer, take all of the readings on one phase
before proceeding to the next, and record the average of the three
rms voltmeter readings as the rms voltage value.
Note: When the tester uses a power supply that is not
synchronized with an electric utility grid, such as a dc/ac motor-
generator set, check the frequency and maintain it within 0.5 percent of the rated frequency of the transformer under
test. A power source that is directly connected to, or synchronized
with, an electric utility grid need not be monitored for frequency.
* * * * *
4.4.3.3 Correction of No-Load Loss to Reference Temperature
After correcting the measured no-load loss for waveform
distortion, correct the loss to the reference temperature. For both
certification to energy conservation standards and voluntary
representations, if the correction to reference temperature is
applied, then the core temperature of the transformer during no-load
loss measurement (Tnm) must be determined within 10 [deg]C of the true average core temperature. For
certification to energy conservation standards only, if the no-load
loss measurements were made between 10 [deg]C and 30 [deg]C, this
correction is not required. Correct the no-load loss to the
reference temperature by using equation 4-2 as follows:
[GRAPHIC] [TIFF OMITTED] TP10MY19.001
Where:
Pnc is the no-load losses corrected for waveform distortion and then
to the reference temperature,
Pnc1 is the no-load losses, corrected for waveform distortion, at
temperature Tnm,
Tnm is the core temperature during the measurement of no-load
losses, and
Tnr is the reference temperature.
* * * * *
[[Page 20730]]
5.0 * * *
5.1 Output Loading Level Adjustment
If the per-unit load selected in section 2.1 is different from
the per-unit load at which the load loss power measurements were
made, then adjust the corrected load loss power, Plc2, by
using equation 5-1 as follows:
[GRAPHIC] [TIFF OMITTED] TP10MY19.002
Where:
Plc is the adjusted load loss power to the per-unit load,
Plc2 is as calculated in section 4.5.3.3,
Por is the rated transformer apparent power (name plate),
Pos is the adjusted rated transformer apparent power, where Pos =
PorL, and
L is the per-unit load, e.g., if the per-unit load is 50 percent
then ``L'' is 0.5.
* * * * *
6.0 Test Equipment Calibration and Certification
Maintain and calibrate test equipment and measuring instruments,
maintain calibration records, and perform other test and measurement
quality assurance procedures according to the following sections.
The calibration of the test set must confirm the accuracy of the
test set to that specified in section 2.3, Table 2.3.
6.1 Test Equipment
The party performing the tests must control, calibrate and
maintain measuring and test equipment, whether or not it owns the
equipment, has the equipment on loan, or the equipment is provided
by another party. Equipment must be used in a manner which assures
that measurement uncertainty is known and is consistent with the
required measurement capability.
6.2 Calibration and Certification
* * * * *
(a) Identify the measurements to be made, the accuracy required
(section 2.3) and select the appropriate measurement and test
equipment;
* * * * *
7.0 Test Procedure for Voluntary Representations
Follow sections 1.0 through 6.0 of this appendix using the per-
unit load and/or reference temperature of interest for voluntary
representations of efficiency, and corresponding values of load loss
and no-load loss at additional per-unit load and/or reference
temperature. Representations made at a per-unit load and/or
reference temperature other than those required to comply with the
energy conservation standards at Sec. 431.196 must be in addition
to, and not in place of, a representation at the required DOE
settings for per-unit load and reference temperature. As a best
practice, the additional settings of per-unit load and reference
temperature should be provided with the voluntary representations.
[FR Doc. 2019-09218 Filed 5-9-19; 8:45 am]
BILLING CODE 6450-01-P