[Federal Register Volume 60, Number 17 (Thursday, January 26, 1995)]
[Rules and Regulations]
[Pages 5096-5127]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-1937]



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DEPARTMENT OF AGRICULTURE
Rural Utilities Service

7 CFR Part 1755


Standard for Splicing Copper and Fiber Optic Cables

AGENCY: Rural Utilities Service, USDA.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The Rural Utilities Service (RUS) hereby amends its 
regulations on telecommunications standards and specifications for 
materials, equipment and construction. The revised standard will update 
the splicing methods and materials used for splicing copper cables 
brought about through technological advancements over the past fifteen 
years and incorporate a section into the standard dealing with the 
splicing methods and materials used to splice fiber optic cables.

DATES: Effective date: February 27, 1995.
    Incorporation by reference: Incorporation by reference of certain 
publications listed in this final rule is approved by the Director of 
the Federal Register as of February 27, 1995.

FOR FURTHER INFORMATION CONTACT: Garnett G. Adams, Chief, Outside Plant 
Branch, Telecommunications Standards Division, Rural Utilities Service, 
room 2844, South Building, U.S. Department of Agriculture, Washington, 
DC 20250-1500, telephone (202) 720-0667.

SUPPLEMENTARY INFORMATION:

Executive Order 12866

    This final rule has been determined to be not significant for the 
purposes of Executive Order 12866 and therefore has not been reviewed 
by the Office of Management and Budget.

Executive Order 12778

    This final rule has been reviewed under Executive Order 12778, 
Civil Justice Reform. If adopted, this final rule will not:
    (1) Preempt any State or local laws, regulations, or policies;
    (2) Have any retroactive effect; and
    (3) Require administrative proceedings before parties may file suit 
challenging the provisions of this rule.

Regulatory Flexibility Act Certification

    The Administrator of RUS has determined that this final rule will 
not have a significant economic impact on a substantial number of small 
entities, as defined by the Regulatory Flexibility Act (5 U.S.C. 601 et 
seq.). This final rule involves standards and specifications, which may 
increase the direct short term costs to RUS borrowers. However, the 
long-term direct economic costs are reduced through greater durability 
and lower maintenance cost over time.

Information Collection and Recordkeeping Requirements

    This final rule contains no information collection or recordkeeping 
requirements under the Paperwork Reduction Act of 1980 (Pub. L. 96-
511).

National Environmental Policy Act Certification

    The Administrator of RUS has determined that this final rule will 
not significantly affect the quality of the human environment as 
defined by the National Environmental Policy Act of 1969 (42 U.S.C. 
4321 et seq.). Therefore, this action does not require an environmental 
impact statement or assessment.

Catalog of Federal Domestic Assistance

    The program described by this final rule is listed in the Catalog 
of Federal Domestic Assistance programs under No. 10.851, Rural 
Telephone Loans and Loan Guarantees, and No. 10.582, Rural Telephone 
Bank Loans. This catalog is available on a subscription basis from the 
Superintendent of Documents, the United States Government Printing 
Office, Washington, DC 20402.

Executive Order 12372

    This final rule is excluded from the scope of Executive Order 
12372, Intergovernmental Consultation that requires intergovernmental 
consultation with state and local officials. A Notice of Final Rule 
titled Department Programs and Activities Excluded from Executive Order 
12372 (50 FR 47034) exempts RUS and RTB loans and loan guarantees, and 
RTB bank loans, to governmental and nongovernmental entities from 
coverage under this Order.

Background

    RUS issues publications titled ``Bulletin'' which serve to guide 
borrowers regarding already codified policy, procedures, and 
requirements needed to manage loans, loan guarantee programs, and the 
security instruments which provide for and secure RUS financing. RUS 
issues standards and specifications for the construction of telephone 
facilities financed with RUS loan funds. RUS is rescinding Bulletin 
345-6, RUS Standard for Splicing Plastic-Insulated Cables, PC-2, and 
codifying the revised standard at 7 CFR 1755.200, RUS Standard for 
Splicing Copper and Fiber Optic Cables.
    RUS Bulletin 345-6 is used by borrowers and contractors as an 
outside plant construction standard for splicing copper cables 
installed in aerial and buried splice closures, ready-access 
enclosures, and buried plant housings. Because of technological 
advancements made in copper cable splicing methods and materials over 
the past fifteen years, the current splicing methods and materials 
relating to copper cables specified in the current standard have become 
outdated. To allow borrowers and contractors to take advantage of these 
improved methods and materials which will reduce installation costs, 
the current standard will be revised to update the copper cable 
splicing methods and materials to reflect these improved methods and 
materials. [[Page 5097]] 
    The current standard does not include splicing methods and 
materials used for fiber optic cables because at the time the standard 
was written no such methods and materials were addressed because RUS 
borrowers were providing telecommunication services to subscribers only 
over copper cables. Since that time RUS borrowers have been providing 
telecommunication services to subscribers over both copper and fiber 
optic cables. Since RUS borrowers are installing fiber optic cables to 
provide subscriber services, the current standard needs to be revised 
to provide borrowers and contractors with standardized splicing methods 
and materials for fiber optic cables.
    This action will allow borrowers and contractors an economical and 
efficient means of reducing their construction costs through the use of 
improved splicing techniques for copper cables and standardized 
splicing methods for fiber optic cables.
    On August 29, 1994, RUS published a proposed rule (59 FR 44347) to 
rescind RUS Bulletin 345-6, RUS Standard for Splicing Plastic-Insulated 
Cables, PC-2, and to codify the revised standard at 7 CFR 1755.200, RUS 
Standard for Splicing Copper and Fiber Optic Cables. Comments on this 
proposed rule were due by October 28, 1994. No comments were received 
by this due date.
    Although no comments were received from any outside party on the 
proposed rule, RUS, upon review of the proposed rule, discovered that 
paragraph (e)(8) which makes reference to paragraphs (g)(4), (g)(5)(i), 
(g)(5)(ii), and (g)(5)(iv) should be changed to reference paragraphs 
(g)(4), and (g)(5)(i) through (g)(5)(iii) because paragraph (g)(5)(iv) 
did not exist in the proposed rule. Therefore RUS will change the 
paragraph (e)(8) to make reference to paragraphs (g)(4), and (g)(5)(i) 
through (g)(5)(iii). This change will not result in any change in the 
technical requirements of paragraph (e)(8).

List of Subjects in 7 CFR Part 1755

    Incorporation by reference, Loan programs--communications, Rural 
areas, Telephone.

    For reasons set out in the preamble, RUS amends chapter XVII of 
title 7 of the Code of Federal Regulations as follows:

PART 1755--TELECOMMUNICATIONS STANDARDS AND SPECIFICATIONS FOR 
MATERIALS, EQUIPMENT AND CONSTRUCTION

    1. The authority citation for part 1755 continues to read as 
follows:

    Authority: 7 U.S.C. 901 et seq., 1921 et seq.


Sec. 1755.97  [Amended]

    2. Section 1755.97 is amended by removing the entry for RUS 
Bulletin 345-6 from the table.
    3. Section 1755.98 is amended by adding a new entry to the table in 
numerical order to read as follows:


Sec. 1755.98  List of telephone standards and specifications included 
in other 7 CFR parts.

* * * * *

------------------------------------------------------------------------
   Section         Issue date                      Title                
------------------------------------------------------------------------
1755.200.....  Jan. 26, 1995.....  RUS Standard for Splicing Copper and 
                                    Fiber Optic Cables.                 
                                                                        
                                                                        
                  *        *        *        *        *                 
------------------------------------------------------------------------

    4. Section 1755.200 is added to read as follows:


Sec. 1755.200  RUS standard for splicing copper and fiber optic cables.

    (a) Scope. (1) This section describes approved methods for splicing 
plastic insulated copper and fiber optic cables. Typical applications 
of these methods include aerial, buried, and underground splices.
    (2) American National Standard Institute/National Fire Protection 
Association (ANSI/NFPA) 70, 1993 National Electrical Code (NEC) 
referenced in this section is incorporated by reference by RUS. This 
incorporation by reference was approved by the Director of the Federal 
Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. A copy 
of the ANSI/NFPA 1993 NEC standard is available for inspection during 
normal business hours at RUS, room 2845, U.S. Department of 
Agriculture, Washington, DC 20250-1500 or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC. 
Copies are available from NFPA, Batterymarch Park, Quincy, 
Massachusetts 02269, telephone number 1 (800) 344-3555.
    (3) American National Standard Institute/Institute of Electrical 
and Electronics Engineers, Inc. (ANSI/IEEE), 1993 National Electrical 
Safety Code (NESC) referenced in this section is incorporated by 
reference by RUS. This incorporation by reference was approved by the 
Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 
1 CFR part 51. A copy of the ANSI/IEEE 1993 NESC standard is available 
for inspection during normal business hours at RUS, room 2845, U.S. 
Department of Agriculture, Washington, DC 20250-1500 or at the Office 
of the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC. Copies are available from IEEE Service Center, 455 Hoes 
Lane, Piscataway, New Jersey 08854, telephone number 1 (800) 678-4333.
    (b) General. (1) Only Rural Utilities Service (RUS) accepted filled 
cable and splicing materials shall be used on outside plant projects 
financed by RUS.
    (2) The installation instructions provided by the manufacturer of 
splicing materials shall be followed except where those instructions 
conflict with the procedures specified in this section.
    (3) Precautions shall be taken to prevent the ingress of moisture 
and other contaminants during all phases of the splicing installation. 
When an uncompleted splice must be left unattended, it shall be sealed 
to prevent the ingress of moisture and other contaminants.
    (4) Minor sheath damage during construction may be repaired if the 
repair is completed immediately and approved by the borrower's resident 
project representative. Minor damage is typically repaired by:
    (i) Scuffing the cable sheath associated with the damaged area;
    (ii) Applying several layers of DR tape over the scuffed and 
damaged area;
    (iii) Applying several layers of plastic tape over the DR tape; and
    (iv) If damage is severe enough to rupture the cable shield, a 
splice closure shall be installed.
    (5) All splice cases installed on RUS toll trunk and feeder cables 
shall be filled, whether aerial, buried, or underground.
    (c) Splicing considerations for copper cables--(1) Preconstruction 
testing. It is desirable that each reel of cable be tested for grounds, 
opens, shorts, crosses, and shield continuity before the cable is 
installed. However, manufacturer supplied test results are acceptable. 
All cable pairs shall be free from electrical defects.
    (2) Handling precautions. The cable manufacturer's instructions 
concerning pulling tension and bending radius shall be observed. Unless 
the cable manufacturer's recommendation is more stringent, the minimum 
bending radius shall be 10 times the cable diameter for copper cables 
and 20 times the cable diameter for fiber optic cables.
    (3) Cable sheath removal. (i) The length of cable sheath to be 
removed shall be governed by the type of splicing hardware used. Follow 
the splice case manufacturer's recommendations. For pedestals or large 
pair count splice housings, consider removing enough cable sheath to 
allow the conductors to [[Page 5098]] extend to the top of the pedestal 
and then to hang downward to approximately 15 centimeters (cm) (6 
inches (in.)) above the baseplate.
    (ii) Caution shall be exercised to avoid damaging the conductor 
insulation when cutting through the cable shield and removing the 
shield. Sharp edges and burrs shall be removed from the cut end of the 
shield.
    (4) Shield bonding and grounding. For personnel safety, the shields 
of the cables to be spliced shall be bonded together and grounded 
before splicing activities are started. (See paragraphs (g)(2), and 
(g)(5)(i) through (g)(5)(iii) of this section for final bonding and 
grounding provisions.)
    (5) Binder group identification. (i) Color coded plastic tie wraps 
shall be placed loosely around each binder group of cables before 
splicing operations are attempted. The tie wraps shall be installed as 
near the cable sheath as practicable and shall conform to the same 
color designations as the binder ribbons. Twisted wire pigtails shall 
not be used to identify binder groups due to potential transmission 
degradation.
    (ii) The standard insulation color code used to identify individual 
cable pairs within 25-pair binder groups shall be as shown in Table 1:

        Table 1.--Cable Pair Identification Within Binder Groups        
------------------------------------------------------------------------
                                                          Color         
                   Pair No.                    -------------------------
                                                     Tip         Ring   
------------------------------------------------------------------------
1.............................................  White.......  Blue.     
2.............................................  White.......  Orange.   
3.............................................  White.......  Green.    
4.............................................  White.......  Brown.    
5.............................................  White.......  Slate.    
6.............................................  Red.........  Blue.     
7.............................................  Red.........  Orange.   
8.............................................  Red.........  Green.    
9.............................................  Red.........  Brown.    
10............................................  Red.........  Slate.    
11............................................  Black.......  Blue.     
12............................................  Black.......  Orange.   
13............................................  Black.......  Green.    
14............................................  Black.......  Brown.    
15............................................  Black.......  Slate.    
16............................................  Yellow......  Blue.     
17............................................  Yellow......  Orange.   
18............................................  Yellow......  Green.    
19............................................  Yellow......  Brown.    
20............................................  Yellow......  Slate.    
21............................................  Violet......  Blue.     
22............................................  Violet......  Orange.   
23............................................  Violet......  Green.    
24............................................  Violet......  Brown.    
25............................................  Violet......  Slate.    
------------------------------------------------------------------------

    (iii) The standard binder ribbon color code used to designate 25-
pair binder groups within 600-pair super units shall be as shown in 
Table 2:

               Table 2.--Cable Binder Group Identification              
------------------------------------------------------------------------
                                                              Group pair
               Group No.                  Color of bindings      count  
------------------------------------------------------------------------
1.....................................  White-Blue..........    1-25    
2.....................................  White-Orange........   26-50    
3.....................................  White-Green.........   51-75    
4.....................................  White-Brown.........  76-100    
5.....................................  White-Slate.........  101-125   
6.....................................  Red-Blue............  126-150   
7.....................................  Red-Orange..........  151-175   
8.....................................  Red-Green...........  176-200   
9.....................................  Red-Brown...........  201-225   
10....................................  Red-Slate...........  226-250   
11....................................  Black-Blue..........  251-275   
12....................................  Black-Orange........  276-300   
13....................................  Black-Green.........  301-325   
14....................................  Black-Brown.........  326-350   
15....................................  Black-Slate.........  351-375   
16....................................  Yellow-Blue.........  376-400   
17....................................  Yellow-Orange.......  401-425   
18....................................  Yellow-Green........  426-450   
19....................................  Yellow-Brown........  451-475   
20....................................  Yellow-Slate........  476-500   
21....................................  Violet-Blue.........  501-525   
22....................................  Violet-Orange.......  526-550   
23....................................  Violet-Green........  551-575   
24....................................  Violet-Brown........  576-600   
------------------------------------------------------------------------

    (iv) Super-unit binder groups shall be identified in accordance 
with Table 3:

                   Table 3.--Super-Unit Binder Colors                   
------------------------------------------------------------------------
                       Pair numbers                         Binder color
------------------------------------------------------------------------
1-600.....................................................  White.      
601-1200..................................................  Red.        
1201-1800.................................................  Black.      
1801-2400.................................................  Yellow.     
2401-3000.................................................  Violet.     
3001-3600.................................................  Blue.       
3601-4200.................................................  Orange.     
4201-4800.................................................  Green.      
4801-5400.................................................  Brown.      
5401-6000.................................................  Slate.      
------------------------------------------------------------------------

    (v) Service pairs in screened cables shall be identified in 
accordance with Table 4:

          Table 4.--Screened Cable Service Pair Identification          
------------------------------------------------------------------------
                                                          Color         
               Service pair No.                -------------------------
                                                     Tip         Ring   
------------------------------------------------------------------------
1.............................................  White.......  Red.      
2.............................................  White.......  Black.    
3.............................................  White.......  Yellow.   
4.............................................  White.......  Violet.   
5.............................................  Red.........  Black.    
6.............................................  Red.........  Yellow.   
7.............................................  Red.........  Violet.   
8.............................................  Black.......  Yellow.   
9.............................................  Black.......  Violet.   
------------------------------------------------------------------------

    (6) Cleaning conductors. It is not necessary to remove the filling 
compound from cable conductors before splicing. However, it is 
permissible to wipe individual conductors with clean paper towels or 
clean cloth rags. No cleaning chemicals, etc., shall be used. Caution 
shall be exercised to maintain individual cable pair and binder group 
identity. Binder group identity shall be maintained by using color 
coded plastic tie wraps. Individual pair identification shall be 
maintained by carefully twisting together the two conductors of each 
pair.
    (7) Expanded plastic insulated conductor (PIC) precautions. Solid 
PIC and expanded (foam or foam skin) PIC are spliced in the same 
manner, using the same tools and materials and, in general, should be 
treated the same. However, the insulation on expanded PIC is much more 
fragile than solid PIC. Twisting or forming expanded PIC into extremely 
compact splice bundles and applying excessive amounts of tension when 
tightening tie wraps causes shiners and, thus shall be avoided.
    (8) Splice connectors. (i) Only RUS accepted filled splice 
connectors shall be used on outside plant projects financed by RUS.
    (ii) Specialized connectors are available for splicing operations 
such as butt splices, in line splices, bridge taps, clearing and 
capping, and multiple pair splicing operations. The splice connector 
manufacturer's recommendations shall be followed concerning connector 
selection and use.
    (iii) Caution shall be exercised to maintain conductor and pair 
association both during and after splicing operations.
    (iv) Splicing operations that involve pairs containing working 
services shall utilize splice connectors that permit splicing without 
the interruption of service.
    (9) Piecing out conductors. Conductors may be pieced-out to provide 
additional slack or to repair damaged conductors. However, the 
conductors shall be pieced-out with conductors having the same gauge 
and type and color of insulation. The conductors used for piecing-out 
shall be from cables having RUS acceptance.
    (10) Splice organization. Spliced pair bundles shall be arranged in 
firm lay-ups with minimum conductor tension in accordance with the 
manufacturer's instructions.
    (11) Binder tape. Perforated nonhygroscopic and nonwicking binder 
tape should be applied to splices housed in filled splice cases. The 
binder tape allows the flow of filling compound while holding the 
splice bundles near the center of the splice case to allow adequate 
coverage of filling compound. [[Page 5099]] 
    (12) Cable tags. Cables shall be identified by a tag indicating the 
cable manufacturer's name, cable size, date of placement, and generic 
route information. Information susceptible to changes caused by future 
cable throws and rearrangements should not be included. Tags on load 
coil stubs shall include the serial number of the coil case, the 
manufacturer's name, and the inductance value.
    (13) Screened cable. Screened PIC cable is spliced in the same 
manner as nonscreened PIC cable. However, special considerations are 
necessary due to differences in the cable design. The transmit and 
receive bundles of the cable shall be separated and one of the bundles 
shall be wrapped with shielding material in accordance with the cable 
manufacturer's recommendations. When acceptable to the cable 
manufacturer, it is permissible to use either the scrap screening tape 
removed from the cable during the sheath opening process provided the 
screening tape is edge coated or new pressure sensitive aluminum foil 
tape over polyethylene tape.
    (14) Service wire connections. (i) Buried service wires may be 
spliced directly to cable conductors inside pedestals using the same 
techniques required for branch cables. Buried service wires may also be 
terminated on terminal blocks inside pedestals in areas where high 
service order activity or fixed count cable administration policies 
require terminal blocks. However, only RUS accepted terminal blocks 
equipped with grease or gel filled terminations to provide moisture and 
corrosion resistance shall be used.
    (ii) Only filled terminal blocks having RUS acceptance shall be 
used on aerial service wire connections.
    (15) Copper cable testing. Copper cable testing shall be performed 
in accordance with RUS Bulletin 345-63, ``RUS Standard for Acceptance 
Tests and Measurements of Telephone Plant,'' PC-4, (Incorporated by 
reference at Sec. 1755.97).
    (16) Cable acceptance. Installed cable shall be tested and pass the 
inventory and acceptance testing specified in the Telephone System 
Construction Contract (Labor and Materials), RUS Form 515. The tests 
and inspections shall be witnessed by the borrower's resident project 
representative. All conductors shall be free from grounds, shorts, 
crosses, splits, and opens.
    (d) Splice arrangements for copper cables--(1) Service distribution 
closures. (i) Ready access closures permit cable splicing activities 
and the installation of filled terminal blocks for service wire 
connections in the same closure. Ready access designs shall allow 
service technicians direct access to the cable core as well as the 
terminal block.
    (ii) Fixed count terminals shall restrict service technician access 
to the cable core. Predetermined cable pairs shall be spliced to the 
terminal leads or stub cable in advance of service assignments.
    (2) Aerial splices. Aerial splice cases accommodate straight 
splices, branch splices, load coils, and service distribution 
terminals. Aerial splicing arrangements having more than 4 cables 
spliced in the same splice case are not recommended. Stub cabling to a 
second splice case to avoid a congested splice is acceptable.
    (3) Buried splices. (i) Direct buried splice cases accommodate 
straight splices, branch splices, and load coils. Direct buried splices 
shall be filled and shall be used only when above ground splicing in 
pedestals is not practicable.
    (ii) A treated plank or equivalent shall be placed 15 cm (6 in.) 
above the buried splice case to prevent damage to the splice case from 
future digging. Where a firm base for burying a splice cannot be 
obtained, a treated plank or equivalent shall be placed beneath the 
splice case.
    (iii) Each buried splice shall be identified for future locating. 
One method of marking the splice point is the use of a warning sign. 
Another method is the burying of an electronic locating device.
    (4) BD-type pedestals. (i) BD-type pedestals are housings primarily 
intended to house, organize, and protect cable terminations 
incorporating splice connectors, ground lugs, and load coils. 
Activities typically performed in pedestals are cable splicing, shield 
bonding and grounding, loading, and connection of subscriber service 
drops.
    (ii) The recommended splice capacities for BD-type pedestals are 
shown in Table 5. However, larger size pedestals are permissible if 
service requirements dictate their usefulness. Table 5 is as follows:

            Table 5.--Splice Capacities for BD-Type Pedestals           
------------------------------------------------------------------------
                                                            Maximum load
                                         Maximum straight   splice pair 
                                          splice maximum      capacity  
                                         load splice pair   using single
                                          capacity using        pair    
             Pedestal type                  single pair    connectors or
                                           connectors or   multiple pair
                                           multiple pair       splice   
                                          splice modules    modules (see
                                                              note 1)   
------------------------------------------------------------------------
BD3, BD3A..............................  100 Pair........  50 Pair.     
BD4, BD4A..............................  200 Pair........  100 Pair.    
BD5, BD5A..............................  600 Pair........  300 Pair.    
BD7....................................  1200 Pair.......  600 Pair.    
BD14, BD14A............................  100 Pair........  50 Pair.     
BD15, BD15A............................  400 Pair........  200 Pair.    
BD16, BD16A............................  600 Pair........  300 Pair.    
------------------------------------------------------------------------
Note 1: This table refers to load coil cases that are to be direct      
  buried with stub cables extending into the pedestal for splicing.     
  Requirements involving individual coil arrangements inside the        
  pedestal should be engineered on a case-by-case basis.                

    (iii) Special distribution pedestals having a divider plate for 
mounting filled terminal blocks are available. Distribution pedestals 
are also equipped with service wire channels for installation of buried 
service wires without disturbing the cabling and gravel inside the base 
of the pedestal. Distribution pedestals are recommended in locations 
where the connection of service wires is required.
    (5) Large pair count splice housings. Large pair count splice 
housings are recommended for areas not suitable for man- holes. The 
recommended capacities are shown in Table 6:

          Table 6.--Splice Capacities for Large Count Housings          
------------------------------------------------------------------------
                                                          Maximum load  
                                    Maximum straight       splice pair  
                                  splice pair capacity   capacity using 
                                    using single pair      single pair  
          Housing type                connectors or       connectors or 
                                  multiple pair splice    multiple pair 
                                         modules         splice modules 
                                                          (see note 1)  
------------------------------------------------------------------------
BD 6000.........................  6,000 Pair..........  3,000 Pair.     
BD 8000.........................  8,000 Pair..........  4,000 Pair.     
BD 10000........................  10,000 Pair.........  5,000 Pair.     
------------------------------------------------------------------------

    (6) Pedestal restricted access inserts. Restricted access inserts 
may be used to protect splices susceptible to unnecessary handling 
where subsequent work activities are required or expected to occur 
after splices have been completed. Restricted access inserts also 
provide moisture protection in areas susceptible to temporary flooding. 
A [[Page 5100]] typical restricted access insert is shown in Figure 1:

BILLING CODE 3410-15-P
[GRAPHIC][TIFF OMITTED]TR26JA95.002



BILLING CODE 3410-15-C [[Page 5101]] 
    (7) Serving Area Interface (SAI) Systems. SAI systems provide the 
cross-connect point between feeder and distribution cables. Connection 
of feeder to distribution pairs is accomplished by placing jumpers 
between connecting blocks. Only RUS accepted connecting blocks having 
grease or gel filled terminations to provide moisture and corrosion 
resistance shall be used.
    (8) Buried cable splicing arrangements. Typical buried cable 
splicing arrangements are illustrated in Figures 2 through 5:

BILLING CODE 3410-15-P
                                                                       
    [[Page 5102]]
    
[GRAPHIC][TIFF OMITTED]TR26JA95.003


[[Page 5103]]

[GRAPHIC][TIFF OMITTED]TR26JA95.004


[[Page 5104]]

[GRAPHIC][TIFF OMITTED]TR26JA95.005


[[Page 5105]]

[GRAPHIC][TIFF OMITTED]TR26JA95.006



BILLING CODE 3410-15-C
[[Page 5106]]

    (9) Underground splices (manholes). Underground splice cases 
accommodate straight splices, branch splices, and load coils. 
Underground splices shall be filled.
    (10) Central office tip cable splices. (i) Filled cable or filled 
splices are not recommended for use inside central offices, except in 
cable vault locations. Outside plant cable sheath and cable filling 
compound are susceptible to fire and will support combustion. Fire, 
smoke, and gases generated by these materials during burning are 
detrimental to telephone switching equipment.
    (ii) Tip cables should be spliced in a cable vault. However, as a 
last resort, tip cables may be spliced inside a central office if flame 
retardant splice cases or a noncombustible central office splice 
housing is used to contain the splice.
    (iii) Splices inside the central office shall be made as close as 
practical to the point where the outside plant cables enter the 
building. Except in cable vault locations, outside plant cables within 
the central office shall be wrapped with fireproof tape or enclosed in 
noncombustible conduit.
    (e) Splicing considerations for fiber optic cables--(1) Connection 
characteristics. Splicing efficiency between optical fibers is a 
function of light loss across the fiber junctions measured in decibels 
(dB). A loss of 0.2 dB in a splice corresponds to a light transmission 
efficiency of approximately 95.5 percent.
    (2) Fiber core alignment. Fiber splicing techniques shall be 
conducted in such a manner that the cores of the fibers will be aligned 
as perfectly as possible to allow maximum light transmission from one 
fiber to the next. Without proper alignment, light will leave the fiber 
core and travel through the fiber cladding. Light outside the fiber 
core is not a usable light signal. Core misalignment is illustrated in 
Figure 6:

BILLING CODE 3410-15-P
[GRAPHIC][TIFF OMITTED]TR26JA95.007



BILLING CODE 3410-15-C
[[Page 5107]]

    (3) Splice loss. (i) Splice loss can also be caused by fiber 
defects such as nonidentical core diameters, cores not in center of the 
fiber, and noncircular cores. Such defects are depicted in Figure 7:

                                                 BILLING CODE 3410-15-P
[[Page 5108]]

[GRAPHIC][TIFF OMITTED]TR26JA95.008


BILLING CODE 3410-15-C
[[Page 5109]]

    (ii) Undesirable splice losses are caused by poor splicing 
techniques including splicing irregularities such as improper cleaves 
and dirty splices. Typical cleave problems are illustrated in Figure 8:

BILLING CODE 3410-15-P
[GRAPHIC][TIFF OMITTED]TR26JA95.009


BILLING CODE 3410-15-C [[Page 5110]] 
    (4) Handling precautions. The following precautions shall be 
observed:
    (i) Avoid damaging the cable during handling operations prior to 
splicing. Minor damage may change the transmission characteristics of 
the fibers to the extent that the cable section will have to be 
replaced;
    (ii) The cable manufacturer's recommendations concerning pulling 
tension shall be observed. The maximum pulling tension for most fiber 
optic cable is 2669 newtons (600 pound-force);
    (iii) The cable manufacturer's recommendations concerning bending 
radius shall be observed. Unless the cable manufacturer's 
recommendation is more stringent, the minimum bending radius for fiber 
optic cable shall be 20 times the cable diameter;
    (iv) The cable manufacturer's recommendations concerning buffer 
tube bending radius shall be observed. Unless the cable manufacturer's 
recommendation is more stringent, the minimum bending radius for buffer 
tubes is usually between 38 millimeters (mm) (1.5 in.) and 76 mm (3.0 
in.). The bending limitations on buffer tubes are intended to prevent 
kinking. Buffer tube kinking may cause excessive optical loss or fiber 
breakage; and
    (v) Handle unprotected glass fibers carefully to avoid introducing 
flaws such as scratched or broken fibers.
    (5) Personnel safety. The following safety precautions shall be 
observed:
    (i) Safety glasses shall be worn when handling glass fibers;
    (ii) Never view open-ended fibers with the naked eye or a 
magnifying device. Improper viewing of a fiber end that is transmitting 
light may cause irreparable eye damage; and
    (iii) Dispose of bare scrap fibers by using the sticky side of a 
piece of tape to pick up and discard loose fiber ends. Fiber scraps 
easily penetrate the skin and are difficult to remove.
    (6) Equipment requirements. (i) Fiber optic splices shall be made 
in areas where temperature, humidity, and cleanliness can be 
controlled. Both fusion and mechanical splicing techniques may require 
a splicing vehicle equipped with a work station that will allow 
environmental control.
    (ii) Both fusion and mechanical splicing techniques are permitted 
on RUS financed projects. When using the mechanical splicing technique, 
only RUS accepted mechanical fiber optic splice connectors can be used.
    (iii) Fusion splicing machines shall be kept in proper working 
condition. Regular maintenance in accordance with the machine 
manufacturer's recommendations shall be observed.
    (iv) Mechanical splicing tools shall be in conformance with the 
tool manufacturer's recommendations.
    (v) An optical time domain reflectometer (OTDR) shall be used for 
testing splices. The OTDR shall be stationed at the central office or 
launch point for testing individual splices as they are made and for 
end-to-end signature tests for the fiber optic link.
    (vi) An optical power meter shall be used for end-to-end cable 
acceptance tests.
    (vii) A prerequisite for the successful completion of a fiber optic 
splicing endeavor is the presence of a talk circuit between the 
splicing technician in the splicing vehicle and the operator of the 
OTDR in the central office. The splicing technician and the OTDR 
operator shall have access to communications with each other in order 
to inform each other as to:
    (A) Which splices meet the loss objectives;
    (B) The sequence in which buffer tubes and fibers are to be 
selected for subsequent splicing operations; and
    (C) The timing required for the performance of OTDR testing to 
prevent making an OTDR test at the same time a splice is being fused.
    (7) Cable preparation. (i) Engineering work prints shall prescribe 
the cable slack needed at splice points to reach the work station 
inside the splicing vehicle. Consideration should be given to the slack 
required for future maintenance activity as well as initial 
construction activities. The required slack may be different for each 
splice point, depending on the site logistics. However, the required 
slack is seldom less than 15 meters (50 feet). The amount of slack 
actually used shall be recorded for each splice point to assist future 
maintenance and restoration efforts.
    (ii) The splice case manufacturer's recommendations concerning the 
amount of cable sheath to be removed shall be followed to facilitate 
splicing operations. The length of the sheath opening shall be 
identified with a wrap of plastic tape.
    (iii) If the cable contains a rip cord, the cable jacket shall be 
ring cut approximately 15 cm (6 in.) from the end and the 15 cm (6 in.) 
of cable jacket shall be removed to expose the rip cord. The rip cord 
shall be used to slit the jacket to the tape mark.
    (iv) If the cable does not contain a rip cord, the cable jacket 
shall be slit using a sheath splitter. No cuts shall be made into the 
cable core nor shall the buffer tubes be damaged.
    (v) If the cable contains an armor sheath, the outer jacket shall 
be opened along the slit and the jacket shall be removed exposing the 
armor sheath. The armor shall be separated at the seam and pulled from 
the cable exposing the inner jacket. The armor shall be removed making 
allowances for a shield bond connector. The inner sheath shall be slit 
using a sheath splitter or rip cord. The cable core shall not be 
damaged nor shall there be any damage to the buffer tubes. The jacket 
shall be peeled back and cut at the end of the slit. The exposed buffer 
tubes shall not be cut, kinked, or bent.
    (vi) After the cable sheath has been removed, the binder tape shall 
be removed from the cable. The cable shall not be crushed or deformed.
    (vii) The buffer tubes shall be unstranded one at a time. The 
buffer tubes shall not be kinked.
    (viii) If the cable is equipped with a strength member, the 
strength member shall be cut to the length recommended by the splice 
case manufacturer.
    (ix) Each buffer tube shall be inspected for kinks, cuts, and flat 
spots. If damage is detected, an additional length of cable jacket 
shall be removed and all of the buffer tubes shall be cut off at the 
point of damage.
    (x) The cable preparation sequence shall be repeated for the other 
cable end.
    (8) Shield bonding and grounding. For personnel safety, the shields 
and metallic strength members of the cables to be spliced shall be 
bonded together and grounded before splicing activities are started. 
(See paragraphs (g)(4), and (g)(5)(i) through (g)(5)(iii) of this 
section for final bonding and grounding provisions).
    (9) Fiber optic color code. The standard fiber optic color code for 
buffer tubes and individual fibers shall be as shown in Table 7:

             Table 7.--Fiber and Buffer Tube Identification             
------------------------------------------------------------------------
         Buffer tube and fiber No.                      Color           
------------------------------------------------------------------------
 1........................................  Blue.                       
 2........................................  Orange.                     
 3........................................  Green.                      
 4........................................  Brown.                      
 5........................................  Slate.                      
 6........................................  White.                      
 7........................................  Red.                        
 8........................................  Black.                      
 9........................................  Yellow.                     
10........................................  Violet.                     
11........................................  Rose.                       
12........................................  Aqua.                       
13........................................  Blue/Black Tracer.          
14........................................  Orange/Black Tracer.        
15........................................  Green/Black Tracer.         
16........................................  Brown/Black Tracer.         
17........................................  Slate/Black Tracer.         
18........................................  White/Black Tracer.         
[[Page 5111]]                                                           
                                                                        
19........................................  Red/Black Tracer.           
20........................................  Black/Yellow Tracer.        
21........................................  Yellow/Black Tracer.        
22........................................  Violet/Black Tracer.        
23........................................  Rose/Black Tracer.          
24........................................  Aqua/Black Tracer.          
------------------------------------------------------------------------

    (10) Buffer tube removal. (i) The splice case manufacturer's 
recommendation shall be followed concerning the total length of buffer 
tube to be removed. Identify the length to be removed with plastic 
tape.
    (ii) Experiment with a scrap buffer tube to determine the cutting 
tool adjustment required to ring cut a buffer tube without damaging the 
fibers.
    (iii) Buffer tubes shall be removed by carefully ring cutting and 
removing approximately 15 to 46 cm (6 to 18 in.) of buffer tube at a 
time. The process shall be repeated until the required length of buffer 
tube has been removed, including the tape identification marker.
    (11) Coated fiber cleaning. (i) Each coated fiber shall be cleaned. 
The cable manufacturer's recommendations shall be followed concerning 
the solvent required to clean the coated fibers. Reagent grade 
isopropyl alcohol is a commonly used cleaning solvent.
    (ii) A tissue or cotton ball shall be soaked in the recommended 
cleaning solvent and the coated fibers shall be carefully wiped one at 
a time using a clean tissue or cotton ball for each coated fiber. 
Caution shall be exercised to avoid removing the coloring agent from 
the fiber coating.
    (12) Fiber coating removal. (i) Fiber coatings shall be removed. In 
accordance with the splicing method used, the splice case 
manufacturer's recommendation shall be followed concerning the length 
of fiber coating to be removed.
    (ii) The recommended length of fiber coating shall be removed only 
on the two fibers to be spliced. Fiber coating removal shall be 
performed on a one-fiber-at-a-time basis as each splice is prepared.
    (13) Bare fiber cleaning. After the fiber coating has been removed, 
the bare fibers shall be cleaned prior to splicing. Each fiber shall be 
wiped with a clean tissue or cotton ball soaked with the cleaning 
solvent recommended by the cable manufacturer. The bare fiber shall be 
wiped one time to minimize fiber damage. Aggressive wiping of bare 
fiber shall be avoided as it lowers the fiber tensile strength.
    (14) Fiber cleaving. Cleaving tools shall be clean and have sharp 
cutting edges to minimize fiber scratches and improper cleave angles. 
Cleaving tools that are recommended by the manufacturer of the splicing 
system shall be used.
    (15) Cleaved fiber handling. The cleaved and cleaned fiber shall 
not be allowed to touch other objects and shall be inserted into the 
splicing device.
    (16) Completion of the splice. (i) In accordance with the method of 
splicing selected by the borrower, the splice shall be completed by 
either fusing the splice or by applying the mechanical connector.
    (ii) Each spliced fiber shall be routed through the organizer tray 
one at a time as splices are completed. The fibers shall be organized 
one at a time to prevent tangled spliced fibers. The splice case 
manufacturer's recommendation shall be followed concerning the splice 
tray selection.
    (17) Fiber optic testing. Fiber optic testing shall be performed in 
accordance with RUS Bulletin 345-63, ``RUS Standard for Acceptance 
Tests and Measurements of Telephone Plant,'' PC-4, (Incorporated by 
reference at Sec. 1755.97).
    (18) Cable acceptance. Installed cable shall be tested and pass the 
inventory and acceptance testing specified in the Telephone System 
Construction Contract (Labor and Materials), RUS Form 515. The tests 
and inspections shall be witnessed by the borrower's resident project 
representative.
    (f) Splice arrangements for fiber optic cables--(1) Aerial splices. 
Cable slack at aerial splices shall be stored either on the messenger 
strand, on the pole, or inside a pedestal at the base of the pole. A 
typical arrangement for the storage of slack cable at aerial splices is 
shown in Figure 9:

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    (2) Buried splices. Buried splices shall be installed in handholes 
to accommodate the splice case and the required splicing slack. An 
alternative to the handhole is a pedestal specifically designed for 
fiber optic splice cases. Typical arrangements for buried cable splices 
are shown in Figures 10 and 11:

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    (3) Underground manhole splices. Underground splices shall be 
stored in manholes on cable hooks and racks fastened to the manhole 
wall. The cable slack shall be stored on cable hooks and racks as shown 
in Figure 12:

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BILLING CODE 3410-15-C [[Page 5117]] 
    (4) Central office cable entrance. (i) Filled cable or filled 
splices are not recommended for use inside central offices except in 
cable vault locations. Outside plant cable sheath and cable filling 
compound are susceptible to fire and will support combustion. Fire, 
smoke, and gases generated by these materials during burning are 
detrimental to telephone switching equipment.
    (ii) As a first choice, the outside plant fiber optic cable shall 
be spliced to an all-dielectric fire retardant cable in a cable vault 
with the all-dielectric cable extending into the central office and 
terminating inside a fiber patch panel.
    (iii) As a second choice, the outside plant cable may be spliced 
inside the central office if a flame retardant fiber optic splice case 
or a noncombustible central office splice housing equipped with 
organizer trays is used to contain the splice.
    (iv) In cases referenced in paragraphs (f)(4)(ii) and (f)(4)(iii) 
of this section, as a minimum the fire retardant all-dielectric cable 
used to provide the connection between the cable entrance splice and 
the fiber patch panel shall be listed as Communication Riser Cable 
(Type CMR) in accordance with Sections 800-50 and 800-51(b) of the 1993 
National Electrical Code.
    (v) Splices inside the central office shall be made as close as 
practicable to the point where the outside plant cables enter the 
building. Except in cable vault locations, outside plant cables within 
the central office shall be wrapped with fireproof tape or enclosed in 
noncombustible conduit.
    (g) Bonding and grounding fiber optic cable, copper cable, and 
copper service wire--(1) Bonding. Bonding is electrically connecting 
two or more metallic items of telephone hardware to maintain a common 
electrical potential. Bonding may involve connections to another 
utility.
    (2) Copper cable shield bond connections. (i) Cable shields shall 
be bonded at each splice location. Only RUS accepted cable shield bond 
connectors shall be used to provide bonding and grounding connections 
to metallic cable shields. The shield bond connector manufacturer's 
instructions shall be followed concerning installation and use.
    (ii) (A) Shield bonding conductors shall be either stranded or 
braided tinned copper wire equivalent to a minimum No. 6 American Wire 
Gauge (AWG) and shall be RUS accepted. The conductor connections shall 
be tinned or of a compatible bimetallic design to avoid corrosion 
problems associated with dissimilar metals. The number of shield bond 
connectors required per pair size and gauge shall be as shown in Table 
8:

        Table 8.--Shield Bond Connectors per Pair Size and Gauge        
------------------------------------------------------------------------
                         Pair size and gauge                            
   19 AWG    ------------------------------------------   No. of shield 
                 22 AWG        24 AWG        26 AWG      bond connectors
------------------------------------------------------------------------
0-25........     0-100         0-150         0-200                  1   
50-100......   150-300       200-400       300-600                  2   
150-200.....   400-600       600-900      900-1500                  3   
300-600.....  900-1200      1200-2100     1800-3600                 4   
------------------------------------------------------------------------

    (B) It is permissible to strap across the shield bond connectors of 
several cables with a single length of braided wire. However, both ends 
of the braid shall be terminated on the pedestal ground bracket to 
provide a bonding loop. Shield bond connection methods for individual 
cables are shown in Figures 13 through 15, and the bonding of several 
cables inside a pedestal using the bonding loop is shown in Figure 16:

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    (3) Buried service wire shield bond connections. Buried service 
wire shields shall be connected to the pedestal bonding and grounding 
system. Typical buried service wire installations are shown in Figures 
17 and 18. In addition to the methods referenced in Figures 17 and 18, 
the shields of buried service wires may also be connected to the 
pedestal bonding and grounding system using buried service wire bonding 
harnesses listed on Page 3.3.1, Item ``gs-b,'' of RUS Bulletin 1755I-
100. RUS Bulletin 1755I-100 may be purchased from the Superintendent of 
Documents, U.S. Government Printing Office, Washington, DC 20402. When 
those harnesses are used they shall be installed in accordance with the 
manufacturer's instructions. Figures 17 and 18 are as follows:

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BILLING CODE 3410-15-C
[[Page 5125]]

    (4) Fiber optic cable bond connections. (i) The cable shield and 
metallic strength members shall be bonded at each splice location. Only 
RUS accepted fiber optic cable shield bond connectors shall be used to 
provide bonding connections to the metallic cable shields. The shield 
bond connector manufacturer's instructions shall be followed concerning 
installation and use.
    (ii) Shield bonding conductors shall be either stranded or braided 
tinned copper wire equivalent to a minimum No. 6 American Wire Gauge 
(AWG) and shall be RUS accepted. The conductor connections shall be 
tinned or of a compatible bimetallic design to avoid corrosion problems 
associated with dissimilar metals.
    (5) Grounding. (i) Grounding is electrically connecting metallic 
telephone hardware to a National Electrical Safety Code (NESC) 
acceptable grounding electrode. Acceptable grounding electrodes are 
defined in the Rule 99A of the NESC.
    (ii) The conductor used for grounding metallic telephone hardware 
shall be a minimum No. 6 AWG solid, bare, copper conductor.
    (iii) For copper and fiber optic cable plant, all cable shields, 
all metallic strength members, and all metallic hardware shall be:
    (A) Grounded at each splice location to a driven grounding 
electrode (ground rod) of:
    (1) At least 1.5 meters (5 feet) in length where the local frost 
level is normally less than 0.30 meters (1 foot) deep; or
    (2) At least 2.44 meters (8 feet) in length where the local frost 
level is normally 0.30 meters (1 foot) or deeper; and
    (B) Bonded to a multi-grounded power system neutral when the splice 
is within 1.8 meters (6 feet) of access to the grounding system of the 
multi-grounded neutral system. Bonding to the multi-grounded neutral of 
a parallel power line may help to minimize telephone interference on 
long exposures with copper cable plant. Consideration, thus, should be 
given to completing such bonds, at least four (4) times each mile, when 
splices are greater than 1.8 meters (6 feet) but less than 4.6 meters 
(15 feet) from access to the multi-grounded neutral.
    (6) Bonding and grounding splice cases. (i) Splice cases are 
equipped with bonding and grounding devices to ensure that cable 
shields and metallic strength members maintain electrical continuity 
during and after cable splicing operations. The splice case 
manufacturer's recommendations shall be followed concerning the bonding 
and grounding procedures. Conductors used for bonding shall be either 
stranded or braided tinned copper wire equivalent to 6 AWG. Conductors 
used for grounding shall be a solid, bare, copper wire equivalent to 
minimum No. 6 AWG.
    (ii) Buried splice cases installed in either handholes or pedestals 
shall be grounded such that the cable shield grounds are attached to a 
common ground connection that will allow the lifting of a ground on the 
cable shield in either direction to permit efficient cable locating 
procedures. As a first choice, buried grounding conductor(s) shall be 
bare. However, if two or more grounding conductors are buried in the 
same trench, they shall be insulated to avoid shorts when a locating 
tone is applied.
    (iii) A typical bonding and grounding method for fiber optic 
splices is shown in Figure 19:

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BILLING CODE 3410-15-C [[Page 5127]] 
    (7) Bonding and grounding central office cable entrances. The RUS 
Telecommunications Engineering and Construction Manual (TE&CM) Section 
810 provides bonding and grounding guidance for central office cable 
entrances. Splicing operations shall not be attempted before all 
metallic cable shield and strength members are bonded and grounded.

    Dated: January 18, 1995.
Bob J. Nash,
Under Secretary, Rural Economic and Community Development.
[FR Doc. 95-1937 Filed 1-25-95; 8:45 am]
BILLING CODE 3410-15-P