Alpha Wire Company MASTER CATALOG - Cuny & Guerber, Inc.

372
TECHNICAL DATA
FLEXIBLE CABLE TESTING CAPABILITIES
Order from Cuny & Guerber Inc., 2100 Kerrigan Ave., Union City, NJ 07087 USA Phone: 201-617-5800 email: sales@cuny.biz web: http://www.cuny.biz
Alpha Wire Company offers a comprehensive, onsite flex testing service, which provides life cycle test data for use in failure analysis and fit for use comparisons.
A state of the art rolling flex test apparatus (Figure 1) is employed to provide rolling flex life data. This device operates continuously in a 24 x 7
environment. Cables are flexed at a rate of approximately 17 cycles per minute over a 14-ft. length of travel. The cables are flex tested within a cable
track system with a continuous 24 VDC electrical signal used to measure conductor continuity. Cycle count accrues only if electrical continuity is maintained
on all conductors in the test samples. Testing stops immediately if continuity
fails. A single cycle is measured when the device completes an “out and
back” motion from 0ft. to 14-ft. and back to 0-ft. in the axis of motion.
Figure 1
ROLLING FLEX
The MIL-C-13777G
BENDING FLEX
bend test employs an
apparatus which subjects
the cable test
sample to bending
±90° about a mandrel,
with a radius of 5/8”
for cables with a diameter
of .750” or larger,
and 3/8” radius for
cables with a diameter
of .749” or smaller.
The test is performed
using a cable test specimen
of 42” to which is
fixed a weight of
Figure 2
between 20 and 50
lbs., based on the circular
mil area (CMA) of the copper conductors in the cable sample. A weight
to CMA chart is supplied in the test procedure. The test cycle rate is 30
cycles per minute.
For the determination of bending and torsional flex life-cycle performance,
Alpha Wire Company employs MIL-C-13777G, General Specification for
Cable, Special Purpose, Electrical.
This standard offers two distinct destructive test procedures that have been found to provide accurate, comparative cable flex test results. Sections 3.7.2,
4.5.4.1 and related figures 3 and 5, of the MIL-C-13777G specification describe the test requirements for bend and twist (torsion). In each instance the
cables are tested at temperatures in the range of 68° to 95° F. A 110 or 220 volt, 60 Hz, AC potential with a prescribed load current of not less than .5
amperes is used to permit the determination of failure caused by broken conductors or by short circuits between conductors. Failure due to either cause
terminates the test. Values obtained are derived from tests of a minimum of three samples per test. If any of the samples tested do not comply with the
requirements, the test is considered a failure.
Figure 3
TORSIONAL FLEX
The MIL-C-13777G torsional test is performed using a cable specimen
length of 66”. The cable is weighted at one end using a 50 lb. weight
for cables containing copper Circular Mil Area (CMA) above 14000 and
20 lbs. for cables containing copper CMA below 14000. 22” inches
from the weighted end, the cable is wound about a mandrel of between
3” and 9”, depending on cable diameter. The cable is affixed to a continuously
rotating arm driven at 30 cycles per minute. Torsion is applied
to the 22” weighted end of the test sample using a helical travel of
±90° over a length of 8”. The torsional stress applied to the cable is
8.2° of motion per inch of cable.
Toll Free: 1-800-52 ALPHA • Telephone: 908-925-8000 • Fax: 908-925-6923 Web Site: www.alphawire.com
Europe/UK Telephone: +44 (0) 1932 772422 • Europe/UK Fax: +44 (0) 1932 772433 Email: info@alphawire.com