FED-STD-228A
4.5 The voltage withstand test may be made before the braiding or finishing operation during
manufacture, but not before any vulcanizing process. Single conductor cable shall be tested between the
conductor and water in which it is immersed. Lead-covered single-conductor cable shall be tested prior to
the application of the lead sheath. Individual conductors of a multiple-conductor cable shall be tested
before assembly as described for single conductor cable. After assembly, the multiple-conductor cable
shall be tested between a single conductor against all other conductors or arranged in two or more
groups for testing; these tests may be conducted without immersion or with immersion using the water as
a ground. After covering, a lead covered cable shall be tested between each conductor and the lead
sheath, or between each conductor and its continguous conductors and to the sheath, without immersion.
4.6 The specimen shall be immersed in water for a period of at least 12 hours before the application of
the potential. Unless otherwise specified in the detail specification or specification sheet, tap water will be
used. The water in which the specimen is tested while immersed, as well as the lead-covered and
multiple-conductor cable, shall be at a temperature of between 10° and 27°C for at least 30 minutes
before the test. No correction factor for temperature is to be applied. The ends of the specimen shall be
kept well above the surface of the water and the covering removed from the surface of the insulation for
several inches at each end in order to reduce surface leakage. If the insulation resistance of the
specimen is to be measured after voltage withstand test, the ends of the specimen shall be dipped into
melted paraffin or other satisfactory material to minimize the effort of moisture in reducing insulation
resistance between the covering and conductor. The water in the bath shall be stirred to maintain a
uniform temperature throughout the bath during the test.
4.7 Starting at zero, the applied voltage shall be increased gradually until the required test value is
reached or until breakdown occurs. The applied voltage shall be increased as uniformly as possible so
that 100 percent of the rated voltage of the specimen is reached in not less than 10 seconds and not
more than 60 seconds. Failure can usually be determined by a sudden current increase and may be
indicated by the tripping of a circuit-breaker in series with the test coil, or by other means. It may also be
indicated by a flash at the point on the specimen where breakdown occurs. If other means fail, the
insulation resistance readings described in method 6031 will detect the voltage withstand failure.
5. RESULTS
5.1 Unless otherwise specified in the detail specification or specification sheet, the entire delivery of the
wire or cable shall be tested.
5.2 Whether the insulation of the entire delivery withstood the specified test voltage without failure shall
be recorded.
5.3 The test voltage an time of application shall be recorded.
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