MIL-DTL-8777F
4.6.3.3 Extruded primary insulation flaws. After application of the extruded silicone insulation, and prior
to the application of any other material, the wire shall be passed through a chain-electrode spark-test
device, without breakdown, using the voltage specified in the applicable MS sheet for extruded insulation.
The electrode shall be of a suitable bead chain of fine mesh construction that will give intimate metallic
contact with practically all the wire insulation surface. Electrode length and speed of wire movement shall
be such that the insulation is subjected to the test voltage for not less than 0.2 second.
4.6.4 Finished wire.
4.6.4.1 Conductor resistance. The dc resistance measurement made on the conductor shall be as
specified in method 6041 of FED-STD-228.
4.6.4.2 Finished wire flaws. The finished wire shall be passed through a chain-electrode spark-test
device, without breakdown, using the voltage specified in the applicable MS sheet for finished wire. The
electrode shall be of a suitable bead chain of fine mesh construction that will give intimate metallic contact
with practically all the wire insulation surface. Electrode length and speed of wire movement shall be
such that the insulation is subjected to the test voltage for not less than 0.2 second.
4.6.4.3 Life cycle.
4.6.4.3.1 Air oven. One inch of the insulation shall be removed from each end of a 24 inch
(609.60 mm) sample of finished wire. The central portion of the specimen shall then be bent at least
halfway around a cylindrical mandrel having a diameter as specified in the applicable MS sheet. Each
end of the conductor shall be loaded in such a manner that the portion of the compound between the
conductor and mandrel is under compression while the conductor is under the tension specified in the
applicable MS sheet. The condition shall be maintained for 120 hours in air maintained at 215° ±5°C.
Following the air oven test, the specimen shall be cooled to 25° ±3°C within 1 hour. Following this
cooling, the wire shall be freed from tension, removed from the mandrel, and straightened. The specimen
4.6.4.3.2 Bend. In a temperature of 23° ±3°C, the specimen shall be secured to the mandrel and the
other end to the load weight as specified in the applicable MS sheet. The mandrel shall be rotated until
the length of the specimen is wrapped around the mandrel under the specified tension and with its
adjoining coils in contact. The mandrel shall then be rotated in reverse direction until the length of the
cable 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 wire.
4.6.4.3.3 Dielectric. The end of the specimen shall be fastened in metallic contact to a metal bar. The
distance between the two uninsulated ends of the wire shall be not greater than the diameter of the
mandrel specified in the applicable MS sheet. The specimen shall be immersed in a solution consisting
of 95 parts water to 5 parts sodium chloride at a temperature of 23° ±3°C so that the insulation protrudes
1.5 inches (38.10 mm) from the surface of the liquid. After submersion for 5 hours, 1,500 volts rms at 60
hertz frequency shall be applied between the conductor and an electrode in contact with the liquid. This
voltage shall be increased at a uniform rate from 0 to 1,500 volts within 0.5 minute and maintained at
1,500 volts for 5 minutes.
4.6.4.3.4 Pitting. The insulation of the specimen shall be removed and the conductor examined for
pitting.
4.6.4.4 Cold bend. One end of a previously untested specimen of suitable length shall be secured to
the mandrel as specified in the applicable MS sheet and the other end to the load weight specified in the
applicable MS sheet. The wire and mandrel assembly shall be lowered to -55° ±3°C at a rate not to
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