UNITED STATES DEPARTMENT OF AGRICULTURE

Rural Utilities Service

BULLETIN 1753F-401(PC-2)

RD-GD-1995-17

SUBJECT: RUS Standard for Splicing Copper and Fiber Optic Cables

TO: All Telephone Borrowers

RUS Telephone Staff

EFFECTIVE DATE: February 27, 1995

EXPIRATION DATE: Date of change in 7 CFR 1755.200 by rulemaking.

OFFICE OF PRIMARY INTEREST: Outside Plant Branch,

Telecommunications Standards Division

PREVIOUS FILING INSTRUCTIONS: This bulletin replaces RUS

Bulletin 345-6, REA Standard for Splicing Plastic-Insulated

Cables, PC-2, issued January 12, 1978.

FILING INSTRUCTIONS: Discard RUS Bulletin 345-6, REA Standard

for Splicing Plastic Insulated Cables, PC-2, dated January 12,

1978, and replace with this bulletin. File with 7 CFR 1755 and

on RUSNET.

PURPOSE: This standard describes approved methods for splicing

plastic-insulated copper and fiber optic cables. This bulletin

is a user friendly guide and a reformat of the text in 7 CFR

1755.200 published at 60 FR 5096, dated January 26, 1995.

Every effort has been made to ensure the accuracy of this

document. However, in case of discrepancies, the regulations at

7 CFR 1755.200 are the authorized sources.

Wally Beyer 3/3/95

_______________________________ ________________________

Administrator Date

Disclaimer: The contents of this guidance document does not have 

the force and effect of law and is not meant to bind the public 

in any way. This document is intended only to provide clarity to 

the public regarding existing requirements under the law or 

agency policies.
Bulletin 1753F-401(PC-2)

Page 2

TABLE OF CONTENTS

CFR to Bulletin Conversion Table .......................... 4

Abbreviations ............................................. 6

1. Scope ..................................................... 7

2. General ................................................... 7

3. Splicing Considerations for Copper Cables ................. 8

4. Splice Arrangement for Copper Cables .................... 13

5. Splicing Considerations for Fiber Optic Cables ........... 16

6. Splice Arrangements for Fiber Optic Cables ............... 21

7. Bonding and Grounding Fiber Optic Cable, Copper Cable,

 and Copper Service Wire .................................. 22

TABLES AND FIGURES

TABLE 1 Cable Pair Identification Within Binder Groups ....... 9

TABLE 2 Cable Binder Group Identification ................... 10

TABLE 3 Super-Unit Binder Colors ............................ 10

TABLE 4 Screened Cable Service Pair Identification .......... 11

TABLE 5 Splice Capacities For BD-Type Pedestals ............. 14

TABLE 6 Splice Capacities For Large Count Housings .......... 15

TABLE 7 Fiber and Buffer Tube Identification ................ 19

TABLE 8 Shield Bond Connectors Per Pair Size and Gauge ...... 23

FIGURE 1 PEDESTAL RESTRICTED ACCESS INSERT .................. 26

FIGURE 2 SERVICE WIRE CONNECTION TO BURIED CABLE ............ 27

FIGURE 3 TYPICAL SPLICE USING SINGLE PAIR CONNECTIONS ....... 28

FIGURE 4 LARGE SPLICE USING MULTIPLE PAIR CONNECTORS ........ 29

FIGURE 5 LARGE SPLICE USING MULTIPLE PAIR CONNECTORS

 MOUNTED ON ORGANIZER RACKS ......................... 30

FIGURE 6 CORE MISALIGNMENT .................................. 31

FIGURE 7 SPLICE LOSS CAUSED BY FIBER MANUFACTURER ........... 32

FIGURE 8 IMPROPER CLEAVES VERSUS PROPER CLEAVE .............. 33

FIGURE 9 AERIAL SPLICE STORED INSIDE PEDESTAL ............... 34

FIGURE 10 BURIED SPLICE STORED INSIDE HANDHOLE .............. 35

FIGURE 11 BURIED SPLICE STORED INSIDE PEDESTAL HOUSING ...... 36

FIGURE 12 MANHOLE SPLICE STORAGE ............................ 37

FIGURE 13 BONDING AND GROUNDING CABLES INSIDE PEDESTALS ..... 38

FIGURE 14 BONDING AND GROUNDING OF LARGE CABLE INSIDE

 PEDESTALS USING MULTIPLE SHIELD BOND CONNECTORS

 AND HARNESS WIRES ................................. 39

FIGURE 15 ALTERNATIVE METHOD OF BONDING AND GROUNDING LARGE

 CABLES IN PEDESTALS USING MULTIPLE SHIELD BOND

 CONNECTORS AND 6 AWG WIRE BRAID ................... 40

FIGURE 16 ALTERNATIVE METHOD OF BONDING AND GROUNDING SEVERAL

 CABLES IN PEDESTALS USING SHIELD BOND CONNECTORS

 AND 6 AWG WIRE BRAID LOOP ......................... 41

FIGURE 17 GROUNDING SERVICE WIRE SHIELDS USING SERVICE

 WIRE CLAMP ........................................ 42
Bulletin 1753F-401(PC-2)

Page 3

FIGURE 18 ALTERNATIVE METHOD OF GROUNDING BURIED SERVICE

 WIRES INSIDE PEDESTALS ............................ 43

FIGURE 19 BONDING AND GROUNDING BURIED FIBER OPTIC SPLICES .. 44

INDEX: Outside Plant

 Construction

 Splicing

 Telecommunications
Bulletin 1753F-401(PC-2)

Page 4

CFR TO BULLETIN CONVERSION TABLE

7 CFR Bulletin 7 CFR Bulletin

1755.200 1753F-401 1755.200 1753F-401

(a) 1. (d)(3) 4.3

(a)(1) 1.1 (d)(3)(i) 4.3.1

(a)(2) 1.2 (d)(3)(ii) 4.3.2

(a)(3) 1.3 (d)(3)(iii) 4.3.3

(b) 2. (d)(4) 4.4

(b)(1) 2.1 (d)(4)(i) 4.4.1

(b)(2) 2.2 (d)(4)(ii) 4.4.2

(b)(3) 2.3 (d)(4)(iii) 4.4.3

(b)(4) 2.4 (d)(5) 4.5

(b)(4)(i) 2.4.1 (d)(6) 4.6

(b)(4)(ii) 2.4.2 (d)(7) 4.7

(b)(4)(iii) 2.4.3 (d)(8) 4.8

(b)(4)(iv) 2.4.4 (d)(9) 4.9

(b)(5) 2.5 (d)(10) 4.10

(c) 3. (d)(10)(i) 4.10.1

(c)(1) 3.1 (d)(10)(ii) 4.10.2

(c)(2) 3.2 (d)(10)(iii) 4.10.3

(c)(3) 3.3 (e) 5.

(c)(3)(i) 3.3.1 (e)(1) 5.1

(c)(3)(ii) 3.3.2 (e)(2) 5.2

(c)(4) 3.4 (e)(3) 5.3

(c)(5) 3.5 (e)(3)(i) 5.3.1

(c)(5)(i) 3.5.1 (e)(3)(ii) 5.3.2

(c)(5)(ii) 3.5.2 (e)(4) 5.4

(c)(5)(iii) 3.5.3 (e)(4)(i) 5.4.1

(c)(5)(iv) 3.5.4 (e)(4)(ii) 5.4.2

(c)(5)(v) 3.5.5 (e)(4)(iii) 5.4.3

(c)(6) 3.6 (e)(4)(iv) 5.4.4

(c)(7) 3.7 (e)(4)(v) 5.4.5

(c)(8) 3.8 (e)(5) 5.5

(c)(8)(i) 3.8.1 (e)(5)(i) 5.5.1

(c)(8)(ii) 3.8.2 (e)(5)(ii) 5.5.2

(c)(8)(iii) 3.8.3 (e)(5)(iii) 5.5.3

(c)(8)(iv) 3.8.4 (e)(6) 5.6

(c)(9) 3.9 (e)(6)(i) 5.6.1

(c)(10) 3.10 (e)(6)(ii) 5.6.2

(c)(11) 3.11 (e)(6)(iii) 5.6.3

(c)(12) 3.12 (e)(6)(iv) 5.6.4

(c)(13) 3.13 (e)(6)(v) 5.6.5

(c)(14) 3.14 (e)(6)(vi) 5.6.6

(c)(14)(i) 3.14.1 (e)(6)(vii) 5.6.7

(c)(14)(ii) 3.14.2 (e)(7) 5.7

(c)(15) 3.15 (e)(7)(i) 5.7.1

(c)(16) 3.16 (e)(7)(ii) 5.7.2

(d) 4. (e)(7)(iii) 5.7.3

(d)(1) 4.1 (e)(7)(iv) 5.7.4

(d)(1)(i) 4.1.1 (e)(7)(v) 5.7.5

(d)(1)(ii) 4.1.2 (e)(7)(vi) 5.7.6
Bulletin 1753F-401(PC-2)

Page 5

(d)(2) 4.2 (e)(7)(vii) 5.7.7

CFR TO BULLETIN CONVERSION TABLE

7 CFR Bulletin 7 CFR Bulletin

1755.200 1753F-401 1755.200 1753F-401

(e)(7)(viii) 5.7.8 (f)(4) 6.4

(e)(7)(ix) 5.7.9 (f)(4)(i) 6.4.1

(e)(7)(x) 5.7.10 (f)(4)(ii) 6.4.2

(e)(8) 5.8 (f)(4)(iii) 6.4.3

(e)(9) 5.9 (f)(4)(iv) 6.4.4

(e)(10) 5.10 (f)(4)(v) 6.4.5

(e)(10)(i) 5.10.1 (g) 7.

(e)(10)(ii) 5.10.2 (g)(1) 7.1

(e)(10)(iii) 5.10.3 (g)(2) 7.2

(e)(11) 5.11 (g)(2)(i) 7.2.1

(e)(11)(i) 5.11.1 (g)(2)(ii)(A) 7.2.2

(e)(11)(ii) 5.11.2 (g)(2)(ii)(B) 7.2.3

(e)(12) 5.12 (g)(3) 7.3

(e)(12)(i) 5.12.1 (g)(4) 7.4

(e)(12)(ii) 5.12.2 (g)(4)(i) 7.4.1

(e)(13) 5.13 (g)(4)(ii) 7.4.2

(e)(14) 5.14 (g)(5) 7.5

(e)(15) 5.15 (g)(5)(i) 7.5.1

(e)(16) 5.16 (g)(5)(ii) 7.5.2

(e)(16)(i) 5.16.1 (g)(5)(iii) 7.5.3

(e)(16)(ii) 5.16.2 (g)(5)(iii)(A) 7.5.3.1

(e)(17) 5.17 (g)(5)(iii)(B) 7.5.3.2

(e)(18) 5.18 (g)(6) 7.6

(f) 6. (g)(6)(i) 7.6.1

(f)(1) 6.1 (g)(6)(ii) 7.6.2

(f)(2) 6.2 (g)(6)(iii) 7.6.3

(f)(3) 6.3 (g)(7) 7.7
Bulletin 1753F-401(PC-2)

Page 6

ABBREVIATIONS

ANSI American National Standards Institute

AWG American Wire Gauge

CFR Code of Federal Regulations

cm Centimeters

CMR Communications Riser Cable

dB Decibels

IEEE Institute of Electrical and Electronics Engineers, Inc

in. Inches

mm Millimeters

NEC National Electrical Code

NESC National Electrical Safety Code

NFPA National Fire Protection Association

OTDR Optical Time Domain Reflectometer

PIC Plastic Insulated Conductor

RUS Rural Utilities Service

SAI Servicing Area Interface

TE&CM Telecommunications Engineering and Construction Manual
Bulletin 1753F-401(PC-2)

Page 7

1. SCOPE

1.1 This standard describes approved methods for splicing

plastic insulated copper and fiber optic cables. Typical

applications of these methods include aerial, buried, and

underground splices.

1.2 Copies of the American National Standard Institute/National

Fire Protection Association (ANSI/NFPA) 70, National Electrical

Code (NEC), referenced in this standard, can be obtained from

NFPA, Batterymarch Park, Quincy, Massachusetts 02269, telephone

number 1 (800) 344-3555.

1.3 Copies of the American National Standard Institute/Institute

of Electrical and Electronics Engineers, Inc. (ANSI/IEEE),

National Electrical Safety Code (NESC), referenced in this

standard, can be obtained from IEEE Service Center, 455 Hoes

Lane, Piscataway, New Jersey 08854, telephone number 1 (800)

678-4333.

2. GENERAL

2.1 Only Rural Utilities Service (RUS) accepted filled cable and

splicing materials shall be used on outside plant projects

financed by RUS.

2.2 The installation instructions provided by the manufacturer

of splicing materials shall be followed except where those

instructions conflict with the procedures specified in this

standard.

2.3 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.

2.4 Minor sheath damage during construction may be repaired if

the repair is completed immediately and is approved by the

borrower's resident project representative. Minor damage is

typically repaired by:

2.4.1 Scuffing the cable sheath associated with the damaged

area;

2.4.2 Applying several layers of DR tape over the scuffed and

damaged area;

2.4.3 Applying several layers of plastic tape over the DR tape;

and
Bulletin 1753F-401(PC-2)

Page 8

2.4.4 If damage is severe enough to rupture the cable shield, a

splice closure shall be installed.

2.5 All splice cases installed on RUS toll trunk and feeder

cables shall be filled, whether aerial, buried, or underground.

3. SPLICING CONSIDERATIONS FOR COPPER CABLES

3.1 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.

3.2 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.

3.3 Cable Sheath Removal:

3.3.1 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 extend to the top of the

pedestal and then hang downward to approximately 15 centimeters

(cm) (6 inches (in.)) above the baseplate.

3.3.2 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.

3.4 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

7.2, and 7.5.1 through 7.5.3 of this standard for final bonding

and grounding provisions.)

3.5 Binder Group Identification:

3.5.1 Color coded plastic tie wraps shall be placed loosely

around each binder group of the 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.
Bulletin 1753F-401(PC-2)

Page 9

3.5.2 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

3.5.3 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:
Bulletin 1753F-401(PC-2)

Page 10

TABLE 2

Cable Binder Group Identification

Group No. Color of Bindings Group Pair 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

3.5.4 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

3.5.5 Service pairs in screened cables shall be identified in

accordance with Table 4:
Bulletin 1753F-401(PC-2)

Page 11

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

3.6 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.

3.7 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.

3.8 Splice Connectors:

3.8.1 Only RUS accepted filled splice connectors shall be used

on outside plant projects financed by RUS.

3.8.2 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.

3.8.3 Caution shall be exercised to maintain conductor and pair

association both during and after splicing operations.
Bulletin 1753F-401(PC-2)

Page 12

3.8.4 Splicing operations that involve pairs containing working

services shall utilize splice connectors that permit splicing

without the interruption of service.

3.9 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.

3.10 Splice Organization: Spliced pair bundles shall be

arranged in firm lay-ups with minimum conductor tension in

accordance with the hardware manufacturer's instructions.

3.11 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.

3.12 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.

3.13 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.

3.14 Service Wire Connections:

3.14.1 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

block equipped with grease or gel filled terminations to provide

moisture and corrosion resistance shall be used.
Bulletin 1753F-401(PC-2)

Page 13

3.14.2 Only filled terminal blocks having RUS acceptance shall

be used on aerial service wire connections.

3.15 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.

3.16 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.

4. SPLICE ARRANGEMENTS FOR COPPER CABLES

4.1 Service Distribution Closures:

4.1.1 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.

4.1.2 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.

4.2 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.

4.3 Buried Splices:

4.3.1 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 inside

pedestals is not practicable.

4.3.2 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

the splice cannot be obtained, a treated plank or equivalent

shall be placed beneath the splice case.

4.3.3 Each buried splice shall be identified for future

locating. One method of marking the splice point is the use of a
Bulletin 1753F-401(PC-2)

Page 14

warning sign. Another method is the burying of an electronic

locating device.

4.4 BD-Type Pedestals:

4.4.1 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.

4.4.2 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 Splice

Maximum Straight Splice Pair Pair Capacity Using

Capacity Using Single Pair Single Pair Connectors

Pedestal Connectors or Multiple Pair or Multiple Pair Splice

Type 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 must be engineered on a case-by-case basis.

4.4.3 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.

4.5 Large Pair Count Splice Housings: Large pair count splice

housings are recommended for areas not suitable for manholes.

The recommended capacities are shown in Table 6:
Bulletin 1753F-401(PC-2)

Page 15

TABLE 6

Splice Capacities for Large Pair Count Housings

Maximum Load Splice

Pair Capacity Using

Maximum Straight Splice Pair Single Pair Connectors

Capacity Using Single Pair or Multiple Pair

Housing Connectors or Multiple Pair Splice Modules

Type 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

4.6 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 typical restricted access

insert is shown in Figure 1.

4.7 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.

4.8 Buried Cable Splicing Arrangements: Typical buried cable

splicing arrangements are illustrated in Figures 2 through 5.

4.9 Underground Splices (Manholes): Underground splice cases

accommodate straight splices, branch splices, and load coils.

Underground splices shall be filled.

4.10 Central Office Tip Cable Splices:

4.10.1 Filled cable or filled splices are not recommended for

use in 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.

4.10.2 Tip cables should be spliced in a cable vault. However,

as a last resort, tip cables may be spliced inside a central
Bulletin 1753F-401(PC-2)

Page 16

office if flame retardant splice cases or a noncombustible

central office splice housing is used to contain the splice.

4.10.3 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.

5. SPICING CONSIDERATIONS FOR FIBER OPTIC CABLES

5.1 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.

5.2 Fiber Core Alignment: Fiber splicing techniques shall be

conducted in such a manner that the cores of the fibers to be

spliced 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.

5.3 Splice Loss:

5.3.1 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.

5.3.2 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.

5.4 Handling Precautions: The following precautions shall be

observed:

5.4.1 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;

5.4.2 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);

5.4.3 The cable manufacturer's recommendations concerning

bending radius shall be observed. Unless the cable

manufacturer's recommendation is more stringent, the minimum
Bulletin 1753F-401(PC-2)

Page 17

bending radius for fiber optic cable shall be 20 times the cable

diameter;

5.4.4 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

5.4.5 Handle unprotected glass fibers carefully to avoid

introducing flaws such as scratched or broken fibers.

5.5 Personnel Safety: The following safety precautions shall be

observed:

5.5.1 Safety glasses shall be worn when handling glass fibers;

5.5.2 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

5.5.3 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.

5.6 Equipment Requirements:

5.6.1 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.

5.6.2 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.

5.6.3 Fusion splicing machines shall be kept in proper working

condition. Regular maintenance in accordance with the machine

manufacturer's recommendations shall be observed.

5.6.4 Mechanical splicing tools shall be in conformance with the

tool manufacturer's recommendations.

5.6.5 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.
Bulletin 1753F-401(PC-2)

Page 18

5.6.6 An optical power meter shall be used for end-to-end cable

acceptance tests.

5.6.7 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 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.

5.7 Cable Preparation:

5.7.1 The 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.

5.7.2 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.

5.7.3 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.

5.7.4 If the cable does not contain 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.

5.7.5 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
Bulletin 1753F-401(PC-2)

Page 19

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.

5.7.6 After the cable sheath has been removed, the binder tape

shall be removed from the cable. The cable shall not be crushed

or deformed.

5.7.7 The buffer tubes shall be unstranded one at a time. The

buffer tubes shall not be kinked.

5.7.8 If the cable is equipped with a strength member, the

strength member shall be cut to the length recommended by the

splice case manufacturer.

5.7.9 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.

5.7.10 The cable preparation sequence shall be repeated for the

other cable end.

5.8 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 7.4, and 7.5.1 through 7.5.3 of

this standard for final bonding and grounding provisions.)

5.9 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
Bulletin 1753F-401(PC-2)

Page 20

14 Orange/Black Tracer

15 Green/Black Tracer

16 Brown/Black Tracer

17 Slate/Black Tracer

18 White/Black Tracer

19 Red/Black Tracer

20 Black/Yellow Tracer

21 Yellow/Black Tracer

22 Violet/Black Tracer

23 Rose/Black Tracer

24 Aqua/Black Tracer

5.10 Buffer Tube Removal:

5.10.1 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.

5.10.2 Experiment with a scrap buffer tube to determine the

cutting tool adjustment required to ring cut a buffer tube

without damaging the fibers.

5.10.3 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.

5.11 Coated Fiber Cleaning:

5.11.1 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.

5.11.2 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.

5.12 Fiber Coating Removal:

5.12.1 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.

5.12.2 The recommended length of fiber coating shall be removed

only on the two fibers to be spliced. Fiber coating removal
Bulletin 1753F-401(PC-2)

Page 21

shall be performed on a one-fiber-at-a-time basis as each splice

is prepared.

5.13 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 avoid as

it lowers the fiber tensile strength.

5.14 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.

5.15 Cleaved Fiber Handling: The cleaved and cleaned fiber

shall not be allowed to touch other objects and shall be inserted

into the splicing device.

5.16 Completion of the Splice:

5.16.1 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.

5.16.2 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.

5.17 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.

5.18 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.

6. SPLICE ARRANGEMENTS FOR FIBER OPTIC CABLES

6.1 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 cable slack at aerial splices is shown in Figure 9.

6.2 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
Bulletin 1753F-401(PC-2)

Page 22

specifically designed for fiber optic splice cases. Typical

arrangements for buried cable splices are shown in Figures 10

and 11.

6.3 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.

6.4 Central Office Cable Entrance:

6.4.1 Filled cable or filled splices are not recommended for use

inside the 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.

6.4.2 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 terminated inside a fiber patch panel.

6.4.3 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.

6.4.4 In cases referenced in Paragraphs 6.4.2 and 6.4.3 of this

standard, 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.

6.4.5 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.

7. BONDING AND GROUNDING FIBER OPTIC CABLE, COPPER CABLE, AND

 COPPER SERVICE WIRE

7.1 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.
Bulletin 1753F-401(PC-2)

Page 23

7.2 Copper Cable Shield Bond Connections:

7.2.1 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.

7.2.2 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 No. of Shield

19 AWG 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

7.2.3 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.

7.3 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.

7.4 Fiber Optic Cable Bond Connections:
Bulletin 1753F-401(PC-2)

Page 24

7.4.1 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.

7.4.2 Shield bonding conductors shall be either stranded or

braided tinned copper wire equivalent to a minimum No. 6 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.

7.5 Grounding:

7.5.1 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.

7.5.2 The conductor used for grounding metallic telephone

hardware shall be a minimum No. 6 AWG solid, bare copper

conductor.

7.5.3 For copper and fiber optic cable plant, all cable shields,

all metallic strength members, and all metallic hardware shall

be:

7.5.3.1 Grounded at each splice location to a driven grounding

electrode (ground rod) of:

a. 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

b. At least 2.44 meters (8 feet) in length where the local

frost level is normally 0.30 meters (1 foot) or deeper;

and

7.5.3.2 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.

7.6 Bonding and Grounding Splice Cases:
Bulletin 1753F-401(PC-2)

Page 25

7.6.1 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.

7.6.2 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.

7.6.3 A typical bonding and grounding method for fiber optic

splices is shown in Figure 19.

7.7 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.