UNITED STATES DEPARTMENT OF AGRICULTURE

Rural Electrification Administration

August 7, 1972 

Supersedes 12/3/71 

REA BULLETIN 345-54

SUBJECT: Revised Page in REA Specification PE-52 

Assistant Administrator - Telephone 

Index:

SPECIFICATION:

Telephone Cable Splicing Connectors 

I. Purpose: To announce the revision of Page 1 of REA Specification

PE-52 for Telephone Cable Splicing Connectors.

II. General: Paragraph 2.11 on Page 1 of PE-52 has been revised to

require that mechanical splicing connectors be used only on

conductors where stripping of conductor insulation is not required.

This revision becomes effective immediately upon issuance of this

bulletin.

III. Availability of Specification: Copies of the revised page of PE-52

will be furnished by REA upon request.

Incorporated by reference in 7 CFR Part 1755.97

REA BULLETIN 345-54

PE-52

DECEMBER 1971

(Supersedes Issue

Dated MARCH 1969)

 specification for

TELEPHONE CABLE

SPLICING CONNECTORS
REA Specification for

TELEPHONE CABLE SPLICING CONNECTORS

1 SCOPE

2 GENERAL

3 MATERIAL

4 SAMPLING PLAN

5 SAMPLE FABRICATION

6 TEST CONDITIONS

7 PHYSICAL AND ELECTRICAL REQUIREMENTS

8 INSTRUMENTATION AND TEST METHODS

9 METHODS OF TEST

10 BASIS FOR ACCEPTANCE

Figures 1 through 7 - Recommended Test Setups
UNITED STATES DEPARTMENT OF AGRICULTURE

Rural Electrification Administration

August 7, 1972

REA SPECIFICATION FOR TELEPHONE CABLE SPLICING CONNECTORS

1. SCOPE

1.1 This specification covers requirements for splicing connectors for

joining insulated copper conductors of aerial, underground and

buried types of cables and wires conforming to REA Specifications PE-22,

PE-23, PE-27, PE-28, PE-38 and PE-50.

2. GENERAL

2.1 These splicing connectors have the function of splicing one, or

more, combinations of No. 26 through No. 19 AWG copper conductors.

2.11 The manufacturer shall specify the wire gauge range for the

connector or connectors submitted to REA for acceptance. The

stripping of conductor insulation will not be permitted.

2.12 The manufacturer shall specify the splicing configuration for

the connector, i.e., inline, butt, tap, or other.

2.13 The connector submitted shall be classified according to the

following:

2.131 Splicing Connector - Shall be capable of meeting the provisions

of paragraphs 9.1, 9.2, 9.3, 9.5, 9.6 (dry), 9.7, and 9.8 of

this specification.

2.132 Moisture Resistant Splicing Connector - Shall be capable of

meeting the provisions of paragraphs 9.1, 9.2, 9.3, 9.4, 9.5,

9.6 (wet), 9.7, and 9.8 of this specification.

3. MATERIAL

3.1 Splicing connectors complying with this specification shall be

compatible with both conductors and insulations of the cables and

wires outlined in paragraph 1.

4. SAMPLING PLAN

4.1 It shall be the manufacturer's responsibility to supply to REA, at

no expense, an adequate number of connectors to test; any special

tools required to apply the connectors; complete instructions for applying

the connectors; and a print of each connector detailing physical dimensions. These instructions shall be the same as those to be provided for

field application. When requested, the manufacturer shall supply to REA

certified data of tests showing compliance with this specification.
- 2 -

5. SAMPLE FABRICATION

5.1 Test Specimens:

Representative samples of the connector are to be assembled per

paragraph 5.2. Wire used shall be conductors from the cables and

wires outlined in paragraph 1.

If a special tool is necessary to obtain proper installation, this

tool is to be used. Specific instructions for assembling connectors

shall be followed in the preparation of the samples.

The manufacturer shall specify the connector wire range. All

samples for testing are to be assembled for each connector type

as follows: ·

5.11 Smallest gauge wire with the largest gauge wire.

5.12 Largest number of smallest gauge wires with one of the largest

gauge wires.

5.13 Largest number of smallest gauge wires.

5.14 Largest number of largest gauge wires.

5.2 Assembly

5.21 Tabulate test samples required per paragraph 5.233 below.

5.22 Cut wires of proper length and gauge for the connector and assemble

all test samples not marked (*). (Use manufacturer's instructions.)

5.23 Test samples marked (*) will require connection resistance tests.

Assemble (*) test samples as follows:

5.231 Cut wires of proper gauge to a 24-inch length.

5.232 Select and identify by the wire color code the wires to be used

for each test sample and tabulate. Straighten all wires. After

specimen assembly, no wires are to be pulled or otherwise deformed except

as specified for a test.

5.233 From each 24-inch length cut enough 4-inch pieces for each

connector to comply with the appropriate subparagraphs of paragraphs 5.1 - (5.11, 5.12, 5.13, 5.14). Save and identify remainder of

24-inch lengths to be used as a control sample for that connector

specimen.

5.234 Connect sample per manufacturer's instructions.

5.235 Determine, from manufacturer's print, the length from outside

edge of the connector body to first metal contact within body.
- 3 - 

Prepare test specimen leads per Figure 1. Do not trim wire ends. The

excess wire will be used to connect to current leads and test fixtures.

5.236 Cut an 8-inch piece of the control wire (5.233 above). Remove 

 insulation completely. (See note). Mark a length of 4.8-inch

± .1-inch in body of wire. (This leaves approximately 1-1/2 inches on 

each end).

Note : Most of the test specimens will require stripped leads. 

It is very important that the stripping action does not 

 nick or deform the conductors nor disturb any connector 

 that may be attached prior to stripping.

5.3 Number of Samples

PARAGRAPH

SAMPLES REQUIRED PER PARAGRAPH 5 .1 

5.11 5.12 5.13 5.14

(*) 9.1 

(*) 9.2 

 9.3 

 

 9.4 

 

(*) 9.5 

 9.6 

 9.7 

 9.8 

Connection Resistance 

Heat-Cold Cycle 

Insulation Resistance - 

 Humidity Cycle

Insulation Resistance - 

 Water Soak

Vibration

Dielectric Strength-Dry

-Wet

Current Cycle

Wire Pull-out (1) 

5 

5 

5 

(15" leads) 

5 

(15" leads) 

5 

5(12" leads) 

5(12" leads) 

5(4" leads) 

5 

5 

5 

(15" leads) 

5 

(15" leads) 

5 

5(4" leads) 

5 5 

5 5 

5 5 

(15” leads) (15" leads) 

5 5 

(15" leads) (15" leads) 

5 5 

5(4" leads) 5(4" leads) 

(10” leads) (10 leads) 

(1) Also requires three 15" samples of each gauge for wire break test.

Take from same wires used to make up samples

(*) These samples are to be tested for connection resistance per paragraph

9.1 before being used in paragraphs 9.2 and 9.5. 

6. TEST CONDITIONS 

6.1 Unless otherwise specified all tests shall be performed at:

6.11 Temperature: 73 ± 3°F 

6.12 Humidity: Up to 55% RH

7. PHYSICAL AND ELECTRICAL REQUIREMENTS

7.1 A connector submitted against the specification shall be capable

of meeting the requirements defined in the following table:
- 4 - 

TEST DESCRIPTION TEST METHOD REQUIREMENT

Connection Resistance Para. 9.1 Connector shall not add more 

than 7% of control wire resistance as connection resistance.

In addition, connector shall 

not add more than 2% of control

wire resistance as resistance

variation.

Heat-Cold Cycle Para. 9.2 Connector shall not add more 

than 2% of control wire resistance after Heat-Cold cycling 

(9% total). Connector shall 

not add more than 2% of 

control wire resistance as

resistance variation after

Heat-Cold cycling (11% total) *

Insulation Resistance 

 Humidity Cycle

Insulation Resistance

Para. 9.3 

Para. 9.4 

500,000 megohms minimum. 

100 volts dc applied. 

100 megohms minimum. 

100 volts dc applied. 

Vibration Para. 9.5 

Dielectric Breakdown Para. 9.6 

Dry

Dielectric Breakdown Para. 9.6 

Wet

Current Cycle Para. 9.7 

Tensile Test Para. 9.8 

Connector shall not add more 

than 5% of control wire resistance after vibration (14% 

total). Connector shall not 

add more than 2% of control

wire resistance as resistance

variation after vibration

(16% total).

2,500 V rms minimum breakdown. 

2,500 V rms minimum breakdown. 

Voltage drop shall not increase 

by more than 5%. 

Wire pull-out to be greater than 

60% of wire breaking force. 

*Failure to meet the requirements of the heat-cold cycling test is not 

necessarily cause for rejection. However, if a connector fails to meet

these requirements, it shall be the responsibility of the manufacturer 

to demonstrate that the cause of the failure was not related to the metal

to metal contacts. The manufacturer must also provide data which indicates to the satisfaction of REA that the connectors could be expected to 

perform satisfactorily in field applications for a suitable period of time.
- 5 -

8. INSTRUMENTATI0N AND TEST METHODS

8.1 The instrumentation listed in this specification is for guide

purposes. Substitutions may be made when necessary as long as

equivalent accuracy will be obtained.

8.11 Test reports of data must include a list of the instruments used

to conduct tests. If substitutions have been made, list characteristics and accuracy.

8.2 Minor variations or modifications of the testing methods or

testing arrangements described in this specification may be

allowed if acceptable to REA. The primary consideration in such

variations or modifications shall be the ability of the tests to produce

comparative data. When test methods or arrangements are to be changed

in any way the manufacturer should request prior acceptance of such

changes.

9. METHODS OF TEST

9.1 Connection Resistance:

9.11 Test Equipment:

"Millivac DC Microvolter".

Variable DC battery supply capable of supplying .100 amperes

continuously. Open circuit voltage 1.57 volts maximum.

Milliammeter DC ± 0.25% full scale.

Four binding posts - with positive screwdown lock for wire (E. F.

Johnson Type III, or equivalent). Mount binding posts as in

Figure 2. Solder current leads to posts P1 and P2.

9.12 Procedure:

9.121 Connect test sample by inserting wire through P3 and into P1 and

tighten. Insert other wire through P4 and into P2 and tighten.

Lead lengths from connector P3 and P4 shall be those established in

paragraph 5.235.

9.122 Set current through sample to .100 ampere.

9.123 Plug "Microvolter" leads into P3 and P4.

9.124 Record voltage drop for each sample.

9.125 Hold connector and twist approximately 90° around wire axis once

in each direction. Record maximum voltage drop change observed.

9.126 Repeat steps 9.121 - 9.123 when measuring control wire sample

for each test specimen. The control wire length between plugs

P3 and P4 shall be 4.8-inch ± 0.1-inch.
- 6 -

9.127 Record voltage drop for test specimen control wire.

9.128 Convert voltage readings to resistance. When the connector has

a significant bulk resistance, that resistance may be separately

calculated by the voltage drop method described above. When this method

is used to arrive at the connection resistance, the method of calculating

the bulk resistance shall be reported along with bulk resistance

calculations.

9.13 Report:

9.131 Report connection resistance in ohms.

9.132 Report change due to twisting as resistance variation in ohms.

9.133 Report control wire resistance in ohms.

9.2 Heat-Cold Cycling Test:

9.21 Samples for Heat-Cold cycling shall be those tested for connection

resistance (paragraph 9.1).

9.22 Test Equipment - Two separate chambers are mounted inline

vertically. The upper chamber is held at 180% (circulating air).

The lower chamber contains liquid nitrogen. An endless chain is looped

over a sprocket housed in the upper chamber. The chain is of sufficient

length to extend to the top of the nitrogen chamber. The sprocket has

an adjustable drive. The chain has alligator clips spaced along its

length to hold test samples. The lower end of the chain shall be set

above the surface of the nitrogen, but close enough so the sample shall

be completely submerged in the liquid nitrogen on each cycle.

The heat chamber may be approximately 6 inches ID and 36 inches

long. A standard nitrogen vessel with 6-inch ID mouth may be

used for the cold chamber. Alternate--The cycling my be done by hand

dipping the test specimen into liquid nitrogen and into a heat source at 

180%F.

9.23 Test Procedure:

9.231 Adjust the chain drive so the test samples will be in the liquid

nitrogen for 20 seconds and in heat chamber for 240 seconds.

9.232 Carefully attach test samples to alligator clips using their wire

leads.

9.233 Run for 100 continuous cycles.

9.234 Allow test samples to return to room temperature (minimum of 30

minutes).

9.235 Using paragraph 9.1 remeasure connection resistance and resistance

variation.
- 7 - 

9.24 Report: 

9.241 Report connector resistance after heat-cold cycling in ohms. 

Report initial connection resistance for the test specimen (per

paragraph 9.1). 

9.242 Report percent resistance variation after heat-cold cycling.

9.3 Insulation Resistance - Humidity Cycle

9.31 Test Equipment: 

One bell jar 12" diameter, 10" high with cover. 

One quart 84% distilled water, 16 glycerine (by weight).

One porcelain grid plate to fit jar.

One pound size #2 lead shot (approximately .140" dia.). 

One lead shot container (plastic with drain holes in bottom). 

One refrigerator.

One oven with timer. 

lOOV dc power source "Keithley" 2004A. 

"Keithley" No. 2008 decade shunt. 

"Keithley" Electrometer No. 200 series.

9.32 Test Procedure:

9.321 Place porcelain grid in bottom of bell jar. Set shot container

 in center of grid. Strip 1/2-inch to 1-inch of insulation from 

the test specimen leads and twist the stripped ends of the leads together. 

Embed test sample 1/2-inch below surface of shot. Dress leads over jar

rim. Do this for each sample. Figure 3 shows the test setup. 

9.322 Use an identified No. 19 AWG wire for the ground electrode. Strip

 2 inches of insulation from one end; insert bared wire into shot. 

Strip 1/2-inch to 1-inch from other end and dress over jar rim. 

9.323 Place cover on top of wires to cover jar and hold wires in place. 

9.324 Allow 24 hours for assembly to come to 73 ± 3°F and any RH up

 to 55% 

9.325 Take initial insulation resistance reading from test specimen

 wires to the 19 AWG ground electrode. 
- 8 -

9.326 Pour water and glycerine mixture into bottom of jar (creates

95% RM).

9.327 Cycle as follows:

140°F for 4 hours.

32°F for 4 hours.

Room temperature for 16 hours.

9.328 Measure insulation resistance from test specimen wires to the

19 AWG ground electrode. Take readings every 5 to 7 days at the

end of a cold cycle. Readings shall be completed within one hour after

removal from refrigerator. Cycling shall be continued for 30 days.

9.33 Insulation resistance shall be reported in megohms. All readings

shall be included.

9.4 Insulation Resistance - Water Soak:

9.41 Test Equipment:

Tap or distilled water into which 5% by weight of sodium chloride

has been dissolved.

Glass jar with copper plate electrode (jar approximately 4"

diameter and 6" deep).

100V dc power source "Keithley" 2004A. 

"Keithley" No. 2008 decade shunt.

"Keithley" Electrometer No. 200 series.

9.42 Test Procedure:

9.421 Strip 1/2-inch to 1-inch of insulation from test specimen leads

and twist the stripped ends of the leads together. Immerse

connector in water. Dress twisted leads over container edge to hold

sample. Repeat for each test specimen. Insert copper electrode in

water.

9.422 Wait two hours for system to stabilize. Take first insulation

resistance readings from test specimen twisted leads to copper

electrode.

9.423 Remove specimens from water after 72 hours and allow them to

stabilize at room temperature and humidity for 72 hours.

9.424 Repeat the above procedure for a total of five (5) cycles.
- 9 -

9.425 Take insulation resistance readings each day while the specimens

are immersed in water.

9.43 Report insulation resistance in megohms. Report shall include all

readings.

9.5 Vibration:

9.51 Test specimens for the vibration test shall be those previously

tested per paragraph 9.1, connection resistance.

9.52 Test Equipment:

Vibration machine capable of going from 10 cps to 55 cps to 10

cps at a uniform rate of change in one minute .06-inch maximum

test specimen excursion. Monitoring circuit capable of detecting

momentary opens of 10 microseconds or longer.

9.53 Test Procedure:

9.531 Attach each test specimen per Figure 4. Handle with care. Do

not disturb test specimen wires more than necessary to place

specimen.

9.532 Electrically connect all test samples and monitoring circuit

in series. Twist and solder wire ends. Do not cut wires short.

9.533 Vibrate samples for 20 minutes in each of three mutually

perpendicular planes, Figure 5.

9.534 Remove and retest connection resistance per paragraph 9.1.

9.54 Report connection resistance before and after vibration in ohms.

Report before and after vibration resistance variation for each

test specimen.

9.6 Dielectric Strength:

9.61 Test Equipment:

Tap or distilled water into which 5% by weight of sodium chloride

has been dissolved.

An ac power source capable of applying 8 kV in 500V rms steps per

second. Unit to be equipped with a circuit breaker to disconnect

at breakdown and a voltmeter to indicate voltages (rms).

Glass jar approximately 4" ID by 3 to 6" deep.

One copper electrode.

Size #2 lead shot (approximately .140" dia.).
- 10 -

9.62 Test Procedure - Dry

9.621 Strip test specimen wire ends 1/2-inch.

9.622 Embed test specimen and copper electrode in shot in jar. Test

specimen shall be inserted to cover connector opening.

9.623 Attach ground voltage lead to copper electrode and high voltage

lead to test specimen lead.

9.624 Increase voltage in 500V rms/sec. steps until breakdown.

9.63 Test Procedure - Wet

9.631 Strip test specimen wire ends 1/2-inch.

9.632 Immerse test specimen and copper electrode in water salt mixture

in jar. Specimen must be completely submerged.

9.633 Attach ground voltage lead to copper electrode and high voltage

lead to test specimen lead.

9.634 Increase voltage in 500V rms/sec. steps until breakdown, or until

8 kV rms is reached.

9.64 Dielectric strength shall be reported in volts (rms) at point of

breakdown. Report should include dry or wet test results.

9.7 Current Cycle:

9.71 Test Equipment:

Hewlett Packard Model 400C VTVM.

ac ammeter 0 - 15 amperes, + 0.5% full scale.

Test panel with:

Variable transformer (i.e., Variac) to control primary of stepdown transformer (120 volt pri./12 volt sec. - 500 VA).

Rack with mounting lugs spaced 5" apart.

Adjustable timer for cycling (Zenith Time Switch Model 9708-0).

9.72 Test Procedure:

9.7201 Strip ends of test specimen leads.

9.7202 Carefully bend and straighten wires so the test specimen

lies approximately midway between mounting lugs and leads are 

straight between lugs without tension.
- 11 - 

9.7203 Solder lead ends to mounting lugs. Figure 6 above test setup. 

9.7204 Repeat for all samples.

9.7205 Connect all samples in series with ammeter and power source.

9.7206 Adjust auto transformer to specified "INITIAL" current (see

 Table 9.73 below). 

9.7207 Allow 15 minutes for system to reach temperature equilibrium.

9.7208 Record voltage drop across each test specimen at lugs. This

 is "INITIAL" reading.

9.7209 Increase current to “TEST” current. Set timer for 45 minutes

 "ON", 15 minutes "OFF", and 50 cycles. 

97210 At the end of 50 cycles reduce current to "FINAL" current

 Record voltage drop across each test specimen at lugs after 15

minutes at "FINAL" current. This is "FINAL" reading. 

9.7211 Calculate and record percent change in "FINAL" voltage from

 "INITIAL" voltage . 

9.73 Test Currents:

WIRE SIZE (AWG)

19 

22 

24 

26 

"INITIAL" & "FINAL"

CURRENT (AMPERES)

11 

9 

4.5 

3 

TEST CURRENT

(AMPERES)

14 

11 

5.6 

3.8 

9.74 Report should consist of millivolts drop at "INITIAL AND FIIIAL" 

 currents.

9.8 Wire Pull-Out

9.81 Test Equipment: 

 "INSTRON" Tensile Tester (or equivalent).

9.82 Test Procedure:

9.821 Set cross head speed to 2 inches per minute. 

9.822 Attach one test specimen lead to the upper jaw and one to lower 

 jaw. Refer to Figure 7 for test setup. If the test specimen

has different size wire, attach largest wire to upper jaw and smallest

wire to lower jaw.
- 12 -

9.823 Test three samples of each gauge of wire to determine breaking

strength.

9.83 Report:

9.831 Record highest load obtained in pounds on each test specimen.

Describe failure as "Pull-out" or "Break".

9.832 Average breaking strength of test wires.

9.833 Report wire pull-out of test specimen as percent of average wire

breaking strength.

10. BASIS F0R ACCEPTANCE

10.1 This specification has been prepared as a basis for the

manufacturer to receive acceptance by REA of telephone cable

splicing connectors. It is not intended that this specification be

used for the inspection of individual shipments of such connectors.
FIG. 1
FIG. 2
FIG. 3
Fig. 4

Fig. 5
FIG. 6
FIG. 7