UNITED STATES DEPARTMENT OF AGRICULTURE

Rural Utilities Service

**BULLETIN 1753F-401(PC-2)**

**SUBJECT:** [RUS Standard for Splicing Copper and Fiber Optic
Cables]{.underline}

**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

**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

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

**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

(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

**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

**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

**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]{.underline}:** 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]{.underline}:** 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]{.underline}:**

**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]{.underline}:** 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]{.underline}:**

**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.

**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.]{.underline} [Tip]{.underline} [Ring]{.underline}

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:

TABLE 2

Cable Binder Group Identification

[Group No.]{.underline} [Color of Bindings]{.underline} [Group Pair
Count]{.underline}

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]{.underline} [Binder Color]{.underline}

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:

TABLE 4

Screened Cable Service Pair Identification

Color

[Service Pair No.]{.underline} [Tip]{.underline} [Ring]{.underline}

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]{.underline}:** 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]{.underline}:** 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]{.underline}:**

**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.

**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]{.underline}:** 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]{.underline}:** 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]{.underline}:** 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]{.underline}:** 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]{.underline}:** 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]{.underline}:**

**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.

**3.14.2** Only filled terminal blocks having RUS acceptance shall be
used on aerial service wire connections.

**3.15 [Copper Cable Testing]{.underline}:** 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]{.underline}:** 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]{.underline}:**

**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]{.underline}:** 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]{.underline}:**

**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 warning sign.
Another method is the burying of an electronic locating device.

**4.4 [BD-Type Pedestals]{.underline}:**

**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]{.underline} [Splice Modules]{.underline} [Modules (See Note
1)]{.underline}

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]{.underline}:** Large pair count
splice housings are recommended for areas not suitable for manholes. The
recommended capacities are shown in Table 6:

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]{.underline} [Splice Modules]{.underline} [(See Note
1)]{.underline}

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]{.underline}:** 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]{.underline}:** 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]{.underline}:** Typical buried
cable splicing arrangements are illustrated in Figures 2 through 5.

**4.9 [Underground Splices (Manholes)]{.underline}:** Underground splice
cases accommodate straight splices, branch splices, and load coils.
Underground splices shall be filled.

**4.10 [Central Office Tip Cable Splices]{.underline}:**

**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 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]{.underline}:** 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]{.underline}:** 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]{.underline}:**

**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]{.underline}:** 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 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]{.underline}:** 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]{.underline}:**

**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.

**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]{.underline}:**

**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 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]{.underline}:** 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]{.underline}:** 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.]{.underline} [Color]{.underline}

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

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]{.underline}:**

**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]{.underline}:**

**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]{.underline}:**

**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 shall be
performed on a one-fiber-at-a-time basis as each splice is prepared.

**5.13 [Bare Fiber Cleaning]{.underline}:** 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]{.underline}:** 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]{.underline}:** 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]{.underline}:**

**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]{.underline}:** 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]{.underline}:** 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]{.underline}:** 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]{.underline}:** 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.

**6.3 [Underground Manhole Splices]{.underline}:** 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]{.underline}:**

**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]{.underline}:** 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.

**7.2 [Copper Cable Shield Bond Connections]{.underline}:**

**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]{.underline} [22 AWG]{.underline} [24 AWG]{.underline} [26
AWG]{.underline} [Bond Connectors]{.underline}

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]{.underline}:**
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]{.underline}:**

**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]{.underline}:**

**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]{.underline}:**

**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]{.underline}:** 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.