55A0121-24-0/2 (063245-000) - Tyco Electronics

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Wire and Cable

501 Oakside Avenue, Redwood City, CA 94063-3800

WIRE AND CABLE, ELECTRIC, RADIATION-CROSSLINKED,

EXTRUDED, MODIFIED, FLUOROPOLYER-INSULATED

COPPER OR COPPER ALLOY

1. SCOPE

1.1 SCOPE

This specification covers radiation-crosslinked, extruded, modified, fluoropolymer-insulated

wire and single- and multiple-conductor cables which may be shielded and jacketed. This

insulation may be used alone or in combination with other insulation materials and is intended

for use as a high-temperature, thin-wall insulation system in military, aerospace, and general

purpose hookup wire applications.

1.2 CLASSIFICATION

Products in accordance with this specification shall be of the following types, as specified in

the applicable specification sheet.

Finished Wire A single conductor, insulated as specified in the applicable specification

sheet.

Finished Cable Any construction other than finished wire, utilizing a wire or wires with

or without shielding, or with or without an outer jacket.

1.2.1 Temperature Rating

The maximum conductor temperature of the finished wire and cable for continuous use shall

be as specified in the applicable specification sheet.

2. APPLICABLE DOCUMENTS

2.1 GOVERNMENT-FURNISHED DOCUMENTS

The following documents, of the issue in effect on date of invitation for bids or request for

proposal, form a part of this specification to the extent specified herein.

SPECIFICATION: 55A

THIS ISSUE: Issue 4

DATE: 7 March 2005

REPLACES: Amendment 1, Issue 3

PAGE: 1 of 18

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Page 2 of 18 SPECIFICATION 55A, ISSUE 4

2.1.1 Department of Defense

SPECIFICATIONS

Federal

UU-T-450 Tissue, Facial

Military

MIL-W-22759 Wire, Electric, Fluoropolymer-Insulated, Copper or Copper Alloy

MIL-D-26937 Detergent, Synthetic, Anionic (Alkyl Benzene Sulfonate)

STANDARDS

Federal

FED-STD-228 Cable and Wire, Insulated; Methods of Testing

Military

MIL-STD-104 Limits for Electrical Insulation Color

MIL-STD-109 Quality Assurance Terms and Definitions

MIL-STD-681 Identification Coding and Application of Hook Up and Lead Wire

MIL-STD-1916 DOD Preferred Methods for Acceptance of Product

(Copies of Department of Defense documents may be obtained from the Naval Publications

and Forms Center, 5801 Tabor Avenue, Philadelphia, Pennsylvania 19120.)

2.1.2 Department of Transportation, Federal Aviation Administration

FEDERAL AVIATION REGULATIONS (FAR)

Part 25 Airworthiness Standards: Transport Category Airplanes

(Copies of Department of Transportation, Federal Aviation Administration documents may be

obtained from the Superintendent of Documents, Government Printing Office, Washington,

D.C. 20402.)

2.2 OTHER PUBLICATIONS

The following documents form a part of this specification to the extent specified herein.

Unless otherwise indicated, the issue in effect on date of invitation for bids or request for

proposal shall apply.

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SPECIFICATION 55A, ISSUE 4 Page 3 of 18

2.2.1 American Society for Testing and Materials (ASTM)

E 104 Standard Recommended Practice for Maintaining Constant Relative

Humidity by Means of Aqueous Solutions

(Copies of ASTM publications may be obtained from the American Society for Testing and

Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103.)

2.2.2 National Electrical Manufacturers Association (NEMA)

WC 27500 Standard for Aerospace and Industrial Electrical Cable

(Copies of NEMA publications may be obtained from the National Electrical Manufacturers

Association, 1300 N. 17th Street, Rosslyn, Virginia 22209.)

3. REQUIREMENTS

3.1 SPECIFICATION SHEETS

The requirements for the individual wires and cables furnished under this specification shall be

as specified herein and in accordance with the applicable specification sheet. Specification

sheet shall mean the Specification Control Drawing (SCD) or the Customer Specification

Report (CSR) when used in conjunction with the SCD, with the SCD taking precedence over

this specification and the CSR taking precedence over the SCD and this specification. An

SCD or CSR may include (but not be limited to) requirements, changes in procedures, or

Quality Assurance Inspection levels which take precedence over this specification.

3.2 QUALIFICATION

The wire and cable furnished under this specification shall be a product which has been tested

and has passed the qualification tests specified herein (see 4.2).

3.3 MATERIALS

3.3.1 Conductor Materials

Conductor materials shall be in accordance with MIL-W-22759 and the applicable

specification sheet.

3.3.2 Shield Materials

Shield strands shall conform to the requirements for conductor materials (3.3.1). When

specified, conforming strands shall be flattened and rectangular in cross section.

3.3.3 Wraps

Wrap tapes, where specified in the applicable specification sheet, shall be applied with an

overlap of 25 percent, minimum, and shall meet the material and construction requirements of

the applicable specification sheet. Overlap is defined as the percentage of tape width covered

by successive turns of tape.

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Page 4 of 18 SPECIFICATION 55A, ISSUE 4

3.3.4 Insulation and Jacket Materials

Insulating materials, used for wire insulation or cable jackets, shall be radiation-crosslinked,

extruded, modified fluoropolymer.

3.4 IN-PROCESS

3.4.1 Conductor Splices

Splices shall be in accordance with MIL-W-22759.

3.4.2 Insulation Flaws

One hundred percent of the wire shall pass the impulse dielectric test or the spark test of MIL-

W-22759 at any designated point or points in the manufacturing process prior to completion of

the finished wire using the voltage specified in the applicable specification sheet.

3.5 FINISHED WIRE AND CABLE

Finished wire and cable shall conform to the following requirements, as applicable, those of

Table 1, and those of the applicable specification sheet (3.1).

3.5.1 Crosslinking Tests and Life Cycle

3.5.1.1 Finished Wire - Accelerated Aging (Crosslinking Proof) and Life Cycle

When finished wire is tested in accordance with 4.6.1, there shall be no cracking of the

insulation and no dielectric breakdown.

3.5.1.2 Finished Cable - Accelerated Aging and Life Cycle

When finished cable is tested in accordance with 4.6.1, there shall be no cracking of the jacket

and, when applicable, no dielectric breakdown of the jacket.

3.5.2 Color

Color shall be in accordance with MIL-STD-104, Class 1. White is preferred for both

insulation and jacket. Colors specified other than white shall be selected in accordance with

MIL-STD-681.

3.5.3 Conductor and Shield Continuity

When finished cable is tested in accordance with WC 27500, there shall be no loss of

continuity in the conductors or shield.

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SPECIFICATION 55A, ISSUE 4 Page 5 of 18

3.5.4 Identification of Product

When specified by the procuring activity, finished wire or cable shall be identified by a

marking applied to the outer surface. The identification shall consist of the appropriate mark

as specified by contract or the applicable specification sheet. The mark color shall be in

accordance with MIL-STD-104, Class 1, and shall be contrasting to that of the marking

surface. Identification shall be applied with the vertical axis of the printed characters parallel

to the longitudinal axis of the wire or cable when the nominal diameter of the marking surface

is 0.050 inch (1.27 mm) or smaller. The vertical axis of the printed characters may be either

perpendicular or parallel to the longitudinal axis of the wire or cable when the nominal

diameter of the marking surface exceeds 0.050 inch (1.27 mm).

3.5.5 Immersion

When finished wire is tested in accordance with MIL-W-22759/32, the diameter increase shall

be not more than 5 percent and there shall be no cracking of the insulation and no dielectric

breakdown.

3.5.6 Insulation Flaws

One hundred percent of finished wire and unshielded, unjacketed cable shall pass the impulse

dielectric test or the spark test of MIL-W-22759 using the voltage specified in the applicable

specification sheet. The test shall be performed during the final winding of the wire or cable

on shipment spools or reels.

3.5.7 Jacket Concentricity

When finished cable is tested in accordance with 4.6.8, the jacket concentricity shall be 70

percent, minimum.

3.5.8 Jacket Flaws

One hundred percent of finished shielded and jacketed cable shall pass the jacket flaws test in

accordance with 4.6.9 using the voltage specified in the applicable specification sheet.

3.5.9 Wrap Test

When tested in accordance with 4.6.14, no cracking of the insulation is allowed. If the

specification sheet does not specify a temperature, the test shall be performed at room

temperature.

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Page 6 of 18 SPECIFICATION 55A, ISSUE 4

TABLE 1.

REQUIREMENTS FOR FINISHED WIRE AND CABLE

Examination or Test

Requirement

Test Method

Quality

Conformance Test

and

Group Number

Finished Wire

Accelerated aging (Crosslinking proof) Applicable specification sheet and 3.5.1.1 4.6.1 2

Blocking Applicable specification sheet and MIL-W-22759 MIL-W-22759

Color Applicable specification sheet and 3.5.2 4.6.4 1

Concentricity Applicable specification sheet MIL-W-22759 2

Conductor diameter Applicable specification sheet 4.6.4 1

Conductor elongation and breaking strength Applicable specification sheet or MIL-W-22759 MIL-W-22759 1

Conductor material Applicable specification sheet and 3.3.1 4.6.4

Conductor resistance Applicable specification sheet MIL-W-22759 1

Conductor stranding Applicable specification sheet 4.6.4 1

Finished wire diameter Applicable specification sheet 4.6.4 1

Flammability Applicable specification sheet 4.6.5 2

Fluoride Extraction Applicable specification sheet 4.6.7

Humidity resistance Applicable specification sheet MIL-W-22759

Identification and color striping durability Applicable specification sheet MIL-W-22759 1

Identification of product Applicable specification sheet and 3.5.4 4.6.4 1

Immersion 3.5.5.1 MIL-W-22759/32

Insulation elongation and tensile strength Applicable specification sheet 4.6.6 1

Insulation flaws Applicable specification sheet and 3.5.6 MIL-W-22759 3

Insulation construction Applicable specification sheet 4.6.4 1

Insulation material Applicable specification sheet and 3.3.4 4.6.4

Insulation resistance Applicable specification sheet MIL-W-22759 1

Insulation thickness Applicable specification sheet 4.6.4 2

Life cycle Applicable specification sheet and 3.5.1.1 4.6.1

Low temperature-cold bend Applicable specification sheet and MIL-W-22759 MIL-W-22759 2

Removability of insulation MIL-W-22759 MIL-W-22759 1

Shrinkage Applicable specification sheet MIL-W-22759 2

Smoke test Applicable specification sheet and MIL-W-22759 MIL-W-22759

Solderability:

Tin coated conductors only

Silver coated conductors only

Applicable specification sheet

MIL-W-22759

Surface resistance Applicable specification sheet 4.6.10

Thermal shock resistance Applicable specification sheet MIL-W-22759 2

Weight Applicable specification sheet MIL-W-22759 1

Wicking Applicable specification sheet 4.6.13 2

Workmanship MIL-W-22759 MIL-W-22759 1

Wrap test Applicable specification sheet and 3.5.9 4.6.14 2

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SPECIFICATION 55A, ISSUE 4 Page 7 of 18

TABLE 1. (Cont'd)

REQUIREMENTS FOR FINISHED WIRE AND CABLE

Examination or Test

Requirement

Test Method

Quality

Conformance Test

and

Group Number

Finished Cable

NON-CSR

CSR

Accelerated aging Applicable specification sheet and 3.5.1.2 4.6.1 2 N/A

Aging stability WC 27500 WC 27500 N/A 2

Blocking Applicable specification sheet and WC 27500 WC 27500 2

Cabling Applicable specification sheet and WC 27500 WC 27500 1 1

Conductor and shield continuity 3.5.3 and WC 27500 WC 27500 3 3

Crosslinked verification WC 27500 WC 27500 and

4.6.11.1

N/A 2

Dielectric withstand Applicable specification sheet and WC 27500 WC 27500 3 3

Dimensions Applicable specification sheet 4.6.4 1 1

Flammability Applicable specification sheet 4.6.5.1 2

Fluoride Extraction Applicable specification sheet 4.6.7

Insulation Flaws Applicable specification sheet and 3.5.6 MIL-W-22759 3 3

Jacket color Applicable specification sheet and 3.5.2 4.6.4 1 1

Jacket concentricity 3.5.7 4.6.8 2 2

Jacket elongation and tensile strength Applicable specification sheet 4.6.6 1 2

Jacket flaws Applicable specification sheet and 3.5.8 4.6.9 3 3

Jacket removability WC 27500 WC 27500 1 1

Jacket material Applicable specification sheet and 3.3.4 4.6.4

Jacket thickness Applicable specification sheet 4.6.4 2 1

Life cycle Applicable specification sheet and 3.5.1.2 4.6.1 N/A

Low temperature-cold bend Applicable specification sheet or WC 27500 WC 27500 2

Shield material and construction Applicable specification sheet, 3.3.2 and WC 27500 WC 27500

Shield coverage Applicable specification sheet WC 27500 1 1

Thermal shock WC 27500 WC 27500 N/A 2

Weight Applicable specification sheet 4.6.12 1 1

Workmanship WC 27500 WC 27500 1 1

Wraps 3.3.3 4.6.4 1 1

NOTE:

1/ A non-CSR cable is a cable that is ordered directly to a Raychem SCD.

A CSR cable is a cable that is ordered to a military or customer specification.

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Page 8 of 18 SPECIFICATION 55A, ISSUE 4

4. QUALITY ASSURANCE PROVISIONS

4.1 RESPONSIBILITY FOR INSPECTION

The supplier is responsible for the performance of all the inspection tests specified herein.

The supplier may utilize his own or any other inspection facility and services acceptable to the

buyer. Inspection records of the examination and tests shall be kept complete and available to

the buyer as required.

4.2 QUALIFICATION INSPECTION

Qualification inspection shall consist of all tests listed in Table 1, as applicable to finished

wire or to finished cable.

4.2.1 Sampling for Qualification Inspection

Except as provided in 4.2.1.1, a finished wire or cable sample of the required length shall be

tested for each range of wire or cable sizes for which qualification is desired. The sample may

be any size of wire or cable within the size range specified below. Ten linear feet (3 linear

meters) of the conductor or shield strand used in the manufacture of the finished wire or cable

sample also shall be tested.

Wire Size Range Required Length of Sample

AWG mm2 ft m

30 through 26 0.057 through 0.15 200 60

24 through 16 0.24 through 1.23 200 60

14 through 10 1.94 through 4.74 200 60

8 through 0000 8.60 through 106.9 200 60

Cable Size Range (Overall Diameter) Required Length of Sample

in. mm ft m

< 0.075 < 1.91 100 30

> 0.075 and < 0.130 > 1.91 and < 3.30 100 30

> 0.130 and < 0.230 > 3.30 and < 5.84 100 30

< 0.230 < 5.84 100 30

4.2.1.1 Optional Qualification Samples

In cases where two or more specification sheets cover finished wire or cable identical in

materials and construction except for conductor (i.e., the specified conductor may be tin-

coated copper, silver-coated high-strength copper alloy or as specified in the applicable

specification sheet), the finished wire or cable sample and conductor or shield strand sample in

accordance with 4.2.1 may qualify any one of the specification sheets. Approval of the

qualification sample shall also qualify the same wire size range or ranges in each of the other

specification sheets. (Note: For purposes of determining identity of construction in

specification sheets under this provision, small differences in specified finished wire or cable

diameter or weight which are due to differences in the specified conductor shall not be

considered as constituting differences in construction of the wires or cables.)

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SPECIFICATION 55A, ISSUE 4 Page 9 of 18

4.2.2 Qualification Test Reports

When requested by the procuring activity, qualification test reports shall be supplied plainly

identified with the following information:

Qualification test report for

WIRE AND CABLE, ELECTRIC, RADIATION-CROSSLINKED, EXTRUDED,

MODIFIED, FLUOROPOLYMER-INSULATED, COPPER OR COPPER ALLOY

Manufacturer's Name

Part number of qualification sample

Part numbers qualified

Specification 55A

4.3 QUALITY CONFORMANCE INSPECTION

Quality conformance inspection shall consist only of those examinations and tests listed in

Table 1 and identified by a group number, as applicable to finished wire or to finished cable.

Quality conformance inspection shall be performed on every lot of wire or cable procured

under this specification.

4.3.1 Sampling for Quality Conformance Inspection

MIL-STD-109 shall apply for definitions of inspection terms used herein. For purposes of this

specification, the following shall apply.

4.3.1.1 Lot

The inspection lot shall include all wire and cable of one part number subjected to inspection

at one time.

4.3.1.2 Unit of Product

The unit of product for determining lot size for sampling shall be one continuous length of

wire or cable as offered for inspection.

4.3.1.3 Sample Unit (Groups 1 and 2 tests)

The sample unit for Groups 1 and 2 tests, except for the Group 1 insulation resistance test,

shall consist of a single length of finished wire or cable chosen at random from the inspection

lot and of sufficient length to permit all applicable examinations and tests. Unless otherwise

specified, the length of the sample unit for Group 1 tests of Table 1 shall be 20 ft (6 m) and the

length of the sample unit for Group 2 tests shall be 25 ft (7.5 m). Not more than one sample

unit for each group of tests shall be taken from a single unit of product.

4.3.1.3.1 Sample Unit for Insulation Resistance Test (Group 1)

The sample unit for the Group 1 insulation resistance test shall be a specimen 26 ft (8 m) in

length selected at random from finished wire which has passed the insulation flaws test.

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4.3.1.4 Inspection Levels and Acceptable Quality Levels (AQL) (Groups 1 and 2 tests)

For Group 1, the inspection level shall be S-2 and the AQL shall be 6.5 percent in accordance

with MIL-STD-1916; for Group 2, the inspection level shall be S-3 and the AQL shall be 1.5

percent.

4.3.1.5 Sampling and Acceptance Level for Group 3 Tests

Unless otherwise specified in the applicable specification sheet, the finished wire or cable

sample for the Group 3 insulation flaws test or jacket flaws test shall be 100 percent of the

finished wire or cable, and every length of the wire or cable shall be fully tested. Portions

showing breakdown in these dielectric tests and ends or portions not subjected to the test shall

be marked or removed. Unless otherwise specified in the applicable specification sheet, the

finished cable sample for the Group 3 conductor and shield continuity and dielectric withstand

tests shall be 100 percent of the finished cable. Portions showing breakdown in these

dielectric tests shall be removed and the remaining lengths tested until no failure occurs.

4.3.1.6 Group N/A

Tests labeled as Group N/A are not to be tested unless they are required on the specification

sheet. In such an event, and unless otherwise specified, they shall be considered a Group 2

test, except Life Cycle, Thermal Shock and Vacuum Stability which shall be considered as

qualification.

4.3.2 Nonconforming Inspection Lots

Disposition of inspection lots found unacceptable under initial quality conformance inspection

shall be in accordance with MIL-STD-1916.

4.4 PROCESS CONTROL INSPECTION

This inspection comprises tests and examinations (Table 2) of such a nature that they cannot

be performed on the finished wire or cable and therefore must be performed at an appropriate

stage of manufacture. Process control inspection shall be performed on every lot of wire or

cable procured under this specification.

TABLE 2.

PROCESS CONTROL INSPECTION

Examination or test Requirement Test Method

Conductor material 3.3.1 4.6.4

Insulating material 3.3.4 4.6.4

Conductor splices 3.4.1 4.6.4

Insulation flaws (impulse dielectric test

or spark test)

3.4.2 MIL-W-22759

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SPECIFICATION 55A, ISSUE 4 Page 11 of 18

4.4.1 Sampling for Process Control Inspection

4.4.1.1 Conductor Material

Process control sample selection and inspection of uninsulated conductor shall be performed at

receiving inspection. The conductor lot size, for purposes of sampling, shall consist of the

number of reels of a given type and size of conductor received at one time from one supplier

against a single purchase order. For lot sizes of 3 reels or less, one 15-ft (4.5-m) length of

conductor shall be selected from each reel. For lot sizes of not less than 4 and not more than

25 reels, a minimum of three 15-ft (4.5-m) lengths of conductor shall be selected at random, in

such a manner as to be representative of the material. For lot sizes in excess of 25 reels, the

inspection level shall be Level 1 and the AQL shall be 4.0 percent in accordance with MIL-

STD-1916.

4.4.1.2 Insulation Flaws (impulse dielectric test or spark test)

One hundred percent of the wire, after the application of the primary insulation, shall be tested

in accordance with the applicable specification sheet and MIL-W-22759.

4.4.2 Rejection and Retest in Process Control Inspection

When a sample selected from an inspection lot fails to meet the specified test (Table 2), except

the insulation flaws test (see 4.4.1.2), no items still on hand or later produced from that lot

shall be accepted until the extent and cause of the failure has been determined.

4.4.2.1 Effect of Process Control Failure on Quality Conformance Testing

Quality conformance testing may be continued during the investigation of the failure of a

process control sample, but final acceptance of the material shall not be made until it is

determined that the lot meets all the process control and quality conformance requirements of

the specification.

4.5 PERIODIC QUALIFICATION RE-EVALUATION

Materials from current production shall be evaluated periodically against the requirements of

Table 1.

4.6 TEST METHODS

4.6.1 Crosslinking Tests and Life Cycle

For finished wire, 1 in. (25 mm) of insulation shall be removed from each end of a 24-in. (600-

mm) specimen. The central portion of the specimen then shall be bent at least halfway around

a horizontally positioned smooth stainless steel mandrel of the diameter specified in the

applicable specification sheet. To prevent sticking of the specimen to the mandrel, the

mandrel shall be covered with polytetrafluoroethylene in the form of either a dispersion

coating or wrapped tape, provided that the diameter of the mandrel still conforms to the

applicable specification sheet. Each end of the conductor shall be loaded with the weight

specified in the applicable specification sheet so that the portion of the insulation between the

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Page 12 of 18 SPECIFICATION 55A, ISSUE 4

conductor and mandrel is under compression while the conductor is under tension. This

specimen, so prepared on the mandrel, shall be conditioned in an air-circulating oven for the

time and at the temperature specified in the applicable specification sheet. For finished cable,

2 in. (50 mm) of the jacket shall be removed from each end of a 24-in. (600-mm) specimen. If

applicable, the shield shall be pushed back and formed into a pigtail at each end of the

specimen. One inch (25 mm) of the insulation of each of the primary wires then shall be

removed from each end of the specimen. The cable specimen shall be conditioned hanging

straight in the oven for the time and at the temperature specified in the applicable specification

sheet. The velocity of air past the specimens (measured at room temperature) shall be between

100 and 200 ft (30 and 60 m) per minute. After conditioning, the oven shall be shut off, the

door opened, and the specimens allowed to cool in the oven for at least 1 hour. When cool,

the finished wire specimens shall be freed from tension, removed from the mandrel, and

straightened. The finished wire and cable specimens then shall be subjected to the bend test

(4.6.2). The voltage withstand test (4.6.11) shall then be conducted on finished wire

specimens and shielded and jacketed cable specimens only.

4.6.2 Bend Test

At a temperature maintained between 20 and 25°C, one end of a finished wire specimen shall

be secured to the mandrel and the other end to the weight specified in the applicable

specification sheet. For finished cable specimens, the mandrel shall be as specified in Table 3

and sufficient weight shall be used to maintain contact with the mandrel. The mandrel shall be

rotated until the full length of the specimen is wrapped around the mandrel and is under the

specified tension with adjoining turns in contact. The mandrel then shall be rotated in the

reverse direction until the full length of the specimen which was outside during the first

wrapping is now next to the mandrel. This procedure shall be repeated until two bends in each

direction have been formed in the same section of the specimen. The specimen then shall be

examined for cracking of the insulation or jacket, as applicable.

TABLE 3.

MANDREL DIAMETERS FOR CABLES FOR BEND TEST AFTER

ACCELERATED AGING AND LIFE CYCLE

Finished Cable Diameter Mandrel Diameter

in. mm in. mm

< 0.083 < 2.11 0.75 19

> 0.083 and < 0.111 > 2.11 and < 2.82 1.00 25

> 0.111 and < 0.139 > 2.82 and < 3.53 1.25 32

> 0.139 and < 0.194 > 3.53 and < 4.93 1.75 44

> 0.194 and < 0.250 > 4.93 and < 6.35 2.25 57

> 0.250 and < 0.334 > 6.35 and < 8.48 3.00 76

> 0.334 and < 0.444 > 8.48 and < 11.3 4.00 102

> 0.444 and < 0.556 > 11.3 and < 14.1 5.00 127

> 0.556 and < 0.667 > 14.1 and < 16.9 6.00 152

> 0.667 and < 0.889 > 16.9 and < 22.6 8.00 203

> 0.889 and < 1.111 > 22.6 and < 28.2 10.0 254

> 1.111 and < 1.556 > 28.2 and < 39.5 14.0 356

> 1.556 and < 2.000 > 39.5 and < 50.8 18.0 457

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SPECIFICATION 55A, ISSUE 4 Page 13 of 18

4.6.3 Examination of Preparation for Delivery

Preparation for delivery of materials ready for shipment shall be examined to determine

compliance with the requirements of Section 5.

4.6.4 Examination of Product

All samples of wire and cable shall be examined to determine conformance with this

specification and the applicable specification sheet with regard to requirements not covered by

specific test methods.

4.6.5 Flammability

4.6.5.1 Procedure 1

4.6.5.1.1 Test Apparatus

The test shall be performed within a test chamber approximately 1 ft (0.3 m) square by 2 ft

(0.6 m) in height, open at the top and front to provide adequate ventilation for combustion but

to prevent drafts. The specimen holder shall be so designed that the lower end of a 24-in.

(600-mm) specimen is held by a clamp, while the upper end of the specimen passes over a

pulley and can be suitably weighted to hold the specimen taut at an angle of 60 degrees with

the horizontal, in a plane parallel to and approximately 6 in. (150 mm) from the back of the

chamber. The test flame shall originate from a Bunsen type gas burner with an 0.250-in. (6-

mm) inlet, a needle valve in the base for gas adjustment, a nominal bore of 0.375 in. (9.5 mm),

and a barrel length of approximately 4 in. (100 mm) above the air inlets. The burner shall be

adjusted to furnish a 3-in. (75-mm) - high conical flame with an inner cone approximately 1 in.

(25 mm) in length and a flame temperature not less than 954°C at its hottest point, as measured

with an accurate thermocouple pyrometer. A sheet of facial tissue conforming to UU-T-450

shall be suspended taut and horizontal 9.5 in. (240 mm) below the point of application of the

flame to the specimen and at least 0.50 in. (13 mm) from the chamber floor, so that any

material dripping from the specimen shall fall upon the tissue.

4.6.5.1.2 Test Procedure

A 24-in. (600-mm) specimen shall be marked at a distance of 8 in. (200 mm) from its lower

end to indicate the point for flame application and shall be placed in the specified 60-degree

position in the test chamber. The lower end of the specimen shall be clamped in position in

the specimen holder and the upper end shall be passed over the pulley of the holder and the

applicable weight shall be attached. For wire, the weight shall be as specified for life cycle

test of the same wire in the applicable specification sheet. For cable, the weight shall be

sufficient to hold the specimen taut throughout the test. With the burner held perpendicular to

the specimen and at an angle of 30 degrees from the vertical plane of the specimen (see Figure

1), the hottest portion of the flame shall be applied to the lower side of the specimen at the test

mark. The period of test flame application shall be 30 seconds and the test flame shall be

withdrawn immediately at the end of that period. The distance of flame travel upward along

the specimen from the test mark and the time of burning after removal of the test flame shall

be recorded; also the presence or absence of flame in the facial tissue due to incendiary

dripping from the specimen. Charred holes or charred spots in the tissue shall be ignored in

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the absence of actual flame. Breaking of the wire specimens in size 24 or smaller shall not be

considered as failure, provided the requirements for flame travel limits, duration of flame, and

absence of incendiary dripping are met. The apparatus and procedure above conform to FAR,

Part 25, Appendix F (g), except that the facial tissue is not required.

Figure 1. Flammability Test Apparatus, Procedure 1 (shown without chamber)

4.6.5.2 Procedure 2

Deleted.

4.6.6 Insulation Elongation and Tensile Strength

Specimens of the entire insulation shall be carefully removed from the conductor and tested

for tensile strength and elongation in accordance with FED-STD-228, Methods 3021 and

3031, respectively, using 1-in. (25-mm) bench marks, a 1-in. (25-mm) initial jaw separation,

and a jaw separation speed of 2 in. (50 mm) per minute. For dual wall insulations, where

separate values are specified for the inner layer and for both layers together, the inner layer

shall be carefully separated from the conductor and outer layer. For cables, the method shall

be the same, but only the cable jacket shall be tested.

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SPECIFICATION 55A, ISSUE 4 Page 15 of 18

4.6.7 Fluoride Extraction

Approximately 0.5 gram of insulation or jacket material shall be removed, cut into 3-inch

(76-mm) lengths, and weighed to the nearest milligram. A polystyrene test tube (without its

cap) shall also be weighed to the nearest 0.1 gram. After filling with approximately 14 ml of

distilled water, the polystyrene test tube shall be reweighed. The insulation or jacket sample

shall then be placed into the test tube, making sure that the sample is fully submerged, and the

test tube cap is tightly attached. The test tube shall then be partially immersed in a 70 ± 2°C

water bath so that the water levels of the bath and the test tube are equal. The test tube shall

be so conditioned for 168 hours with the set-up being periodically checked to make sure that

the sample is still submerged. After conditioning, the test tube shall be removed from the bath

and allowed to cool. The cap shall then be removed from the test tube, and the tube, water and

sample shall be weighed to determine the water weight loss. If the water loss is more than 0.5

gram, the test shall be rerun. Otherwise, 5 ml of the test tube water shall be analyzed for

fluoride ion content using an Ion Chromatograph. The fluoride ion content shall be reported in

ppm of water.

A blank test in accordance with 4.6.7.1 should also be conducted in case the result is needed

for calculation purposes.

4.6.7.1 Blank Test

A blank test follows the same procedure as 4.6.7 except that a specimen is not included. What

is tested is the distilled water and the sample tube. Ideally, there are no fluoride ions in either

the test tube or the distilled water such that the result for the blank test would be zero.

However, there may be a low non-zero result (i.e. 0.005 ppm). If this occurs, the ppm of

fluoride for the blank test must be subtracted from the ppm of fluoride obtained from the

specimen. A blank test also performs the same function as a calibration as it can indicate a

problem with the test procedure. For example, should the blank test produce a result of 15

ppm of fluoride, this would be an indication that the ion chromatograph is not functioning

correctly, tap water was used in place of distilled water, etc.

4.6.7.2 Calculation

If necessary, the blank test result shall be subtracted from the sample result to obtain the net

fluoride ion content (ppm). The fluoride ion content, of the insulation or jacket weight, shall

then be calculated as follows:

F ion = Net F ion (ppm) x Original water weight / Sample weight

4.6.8 Jacket Concentricity

The concentricity of the cable jacket shall be determined by first locating and recording the

minimum wall thickness measured on a cross section of the jacket. The maximum wall

thickness of this same cross section of the jacket shall be measured and recorded. The ratio of

the minimum wall thickness to the maximum wall thickness shall define the concentricity. All

wall thickness measurements shall be made under suitable magnification. The wall thickness

shall be the radial distance between the inner and outer rim of the jacket.

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4.6.9 Jacket Flaws

Finished cable shall be tested in accordance with the jacket flaws test of WC 27500, or the

procedure of the impulse dielectric test of MIL-W-22759 with the shield grounded at one or

both ends.

4.6.10 Surface Resistance

The surface resistance of the finished wire shall be measured using the procedure of FED-

STD-228, Method 6041, except that the required humidity shall be maintained by ASTM E

104, Method A and without instrumentation of the chamber. All specimens, after having been

provided with the required electrodes, but prior to testing, shall be cleaned by the procedure

described in the test method. The specimens shall be positioned in the test chamber so that

their ends are at least 1 in. (25 mm) from any wall of the chamber.

4.6.11 Voltage Withstand Test

The uninsulated ends of the specimen shall be attached to an electric lead. The specimen shall

be immersed in a 5-percent, by weight, solution of sodium chloride in water at 20 to 25°C,

except that the uninsulated ends and 1.5 in. (38 mm) of insulated wire or cable at each end of

the specimen shall protrude above the surface of the solution. After immersion for 5 hours,

the voltage specified in the applicable specification sheet at 60 Hz shall be applied between the

conductor or the shield, as applicable and an electrode in contact with the liquid. The voltage

shall be gradually increased at a uniform rate from zero to the specified voltage in 0.5 minute,

maintained at that voltage for a period of 5 minutes for finished wire specimens and 1 minute

for finished cable specimens, and gradually reduced to zero in 0.5 minute.

4.6.11.1 Cables Containing a Jacket Between Two Shields

For cables containing a jacket between two shields, the voltage withstand test of 4.6.11 or WC

27500, as applicable, shall additionally be conducted on the inner jacket with the voltage as

specified in the applicable specification sheet being applied between the two shields.

4.6.12 Weight

The weight of each lot of finished cable shall be determined in accordance with the procedure

for finished wire in MIL-W-22759.

4.6.13 Wicking

A specimen of each finished wire size to be tested shall be cut with square ends. The length of

the specimen shall be 4 ± 1/16 in. (100 ± 2 mm). The specimen shall be vertically immersed

for 2 in. (50 mm) of its length in a fluorescent dye solution contained in an open test tube and

shall be conditioned thus for 24 hours at room temperature in a draft-free room. The

fluorescent dye solution shall be prepared by dissolving 0.02 g of Rhodamine B dye in 30 ml

of ethyl alcohol and diluting with 2 liters of distilled water containing 3 ml of an anionic

wetting agent conforming to MIL-D-26937. After conditioning, the specimen shall be

removed from the fluorescent dye solution and excess solution on the surface shall be

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SPECIFICATION 55A, ISSUE 4 Page 17 of 18

removed immediately by wiping gently with a clean, dry, lint-free cloth. The outer layer of

insulation shall be removed from the specimen and the outside of the inner layer of insulation

and the inside of the outer layer of insulation shall be examined under ultraviolet illumination

for evidence of fluorescent dye. The distance that the dye has traveled from the end of the

specimen between the outer and inner layers shall be recorded as the distance of wicking.

4.6.14 Wrap Test

A specimen of finished wire shall be tested in accordance with MIL-W-22759 "wrap back

test" for extruded insulation, except 8 AWG and larger shall be wound around a mandrel with

the diameter 3 times the outside diameter of the wire.

5. PREPARATION FOR DELIVERY

5.1 PACKAGING AND PACKING

5.1.1 Wire and cable shall be delivered wound on reels or spools in accordance with 5.1.2. Unless

otherwise specified, the minimum acceptable finished wire lengths shall conform to Table 4.

The wire and cable shall be wound on the reel or spool in such a manner that all ends are

accessible.

TABLE 4.

FINISHED WIRE LENGTHS

Wire Size Range Minimum percentage of total length in shipment

with lengths greater than:

AWG mm2 1000 ft

(305 m)

500 ft

(152 m)

100 ft

(30.5 m)

50 ft

(15.2 m)

30 through 16 0.057 through 1.23 50 80 100 ---

14 through 10 1.94 through 4.74 30 50 100 ---

8 through 0000 8.60 through 106.9 -- 50 80 100

5.1.2 Reels and Spools

Reels and spools shall be of a nonreturnable type. Each reel and spool shall have an

appropriate diameter for the respective wire size. In no case shall the barrel of the reel or

spool have a diameter less than 3.5 in. (90 mm). Reels and spools shall be suitably finished to

prevent corrosion under typical storage and handling conditions.

5.1.3 Containers

Unless otherwise specified (see 6.1), wire and cable shall be delivered in standard commercial

containers so constructed as to ensure acceptance by common or other carrier for safe

transportation at the lowest rate to the point of delivery.

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Page 18 of 18 SPECIFICATION 55A, ISSUE 4

5.1.4 Marking of Shipments

All spools or reels and shipping container labels shall be identified with the following

information:

Specification Part Number

Lot Number

Quantity in Feet (or Meters)

Name of Manufacturer

6. NOTES

6.1 ORDERING DATA

Procurement documents should specify the following:

(a) Title, number, and date of this specification

(b) Applicable specification sheet part number

(d) Special preparation for delivery requirements, if applicable.

6.2 METRIC UNITS

Metric units are for information only.

6.3 MIL-W-22759

Wherever MIL-W-22759 refers to "applicable specification sheet", use the applicable Tyco

Electronics specification sheet (3.1).