MIL-DTL-12285F
4.7.4 Dielectric withstanding. To determine conformance to 3.5.2, the switches shall be tested in
accordance with MIL-STD-202, method 301. The following conditions are applicable:
a. The switch temperature shall be maintained at 14º ± 3ºC (25º ± 5ºF) below the rated
contact closing temperature.
b. A potential of 440 volts root mean square (vrms) shall be applied.
c.
The potential shall be 60 cycles per second (cps), alternating current (ac).
d. One conductor shall be attached to the switch terminal and one to the switch body.
e. After the voltage application the switch shall be examined and the calibration checked as
specified in 4.7.1.
4.7.5 High temperature resistance. To determine conformance to 3.5.3, the switch shall be heated for
one minute at 177º ± 3ºC (350º ± 5ºF) in an oil bath, cooled to room temperature, and then tested as
specified in 4.7.3.
4.7.6 Waterproofness. To determine conformance to 3.5.4, the switch shall be subjected to the
4.7.6.1 Waterproofness test method
4.7.6.1.1 Pre-test of switch. Prior to submersion, the sample switch shall be installed in a test circuit
equivalent to the normal dry environment and operating both mechanically and electrically, as applicable,
for a period of 30 minutes at full rated current and voltage.
4.7.6.1.2 Submersion. The component with its electrical connections shall be submerged in a
container with the uppermost surface a minimum of one inch below the surface of the saline solution and
installed in the chamber. The component shall be carefully observed during its entire period of
submersion and shall be operated while submerged for 30 minutes at full rated current and voltage. The
chamber shall be evacuated to a pressure six pounds below atmospheric so as to apply a minimum of six
pounds per square inch (psi) in internal pressure to all voids within the component. Test results obtained
shall be compared with the data obtained from the test of 4.7.6.1.1. During this period the component
shall be carefully observed for poor seals, as evidenced by bubbles escaping from the interior of the
component (see 4.7.6.1.5). Leakage thus indicated shall be considered as noncompliance with the
waterproofness requirement and the component shall be rejected. Bubbles that are the result of
entrapped air on the exterior surfaces of the component shall not be considered a leak.
4.7.6.1.3 Chamber pressure. The chamber shall then be pressurized to six pounds above
atmospheric and the component again operated for 30 minutes. Test results obtained shall be compared
with the data from the test of 4.4.
4.7.6.1.4 Test results. The switch shall evidence no leakage and shall be mechanically and
electrically operable during and subsequent to submersion, when subjected to the tests specified in
4.7.6.1.5 Leakage definition. The term "leakage", as used in this document, is intended to mean that
there shall be no bubbles escaping from the interior of the component when the test chamber is
evacuated to a pressure six pounds below atmospheric
4.7.7 Corrosion. To determine conformance to 3.5.5, the switch shall be subjected to the salt spray
(fog) test specified in MIL-STD-202, method 101, except that the test duration shall be 200 hours. After
the test, the switch shall be tested as specified in 4.7.3. Resultant change in calibration (see 3.5.1) shall
be no more than ± 3ºC (5.4ºF).
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