MIL-DTL-24317B
4.8.16 Moisture resistance (see 3.19). Switches shall be tested in accordance with method 106 of MIL-
STD-202. The following details and exceptions shall apply:
(a) Mounting By normal means, on corrosion-resistant metal panel positioned 15 degrees from the
vertical, with the switch actuator up.
(b) Initial measurements Not applicable.
(c) Polarization voltage During steps 1 to 6 inclusive, 100 volts dc shall be applied and the metal
panel. The negative polarity shall be applied to the metal panel.
(d) Loading voltage Not applicable.
(e) Steps 7a and 7b Not applicable.
(f) Final measurements Unless otherwise specified (see 3.1), immediately after the conclusion of
the test and while the switches are still in the humidity chamber, and also at the end of the drying
period, insulation resistance shall be measured as specified in 4.8.15.
After the test, switches shall be examined for breaking, cracking, spalling, and loosening of terminals,
pitting of plated metal, and color fading of lenses, when applicable.
4.8.17 Mechanical endurance (see 3.20). Switches shall be subjected to 50,000 cycles of operation at
room temperature. The cycling rate shall not exceed 100 cycles of operation per minute. A cycle of
operation shall be the movement of the actuating means through the entire range of its travel causing the
switch contacts to change from one position to another.
4.8.18 Sand and dust (when applicable, see 3.21). Switches shall be tested in accordance with
method 110, test-condition letter B, of MIL-STD-202. During the test, the switches shall be mechanically
operated for 2,5000 cycles. The cycling rate shall not exceed 60 cycles of operation per minute.
replaced in service without disassembly shall be disassembled and then reassembled to the switch.
4.8.19.1 Watertight. The switch, mounted on a test enclosure by normal mounting means, shall be
submerged in water to a depth of 6 ± 2 inches, and subjected to a gradually increasing pressure at a rate
of 1 pound per square inch gage (psig) every 2 minutes until a pressure of 15 psig is reached, and
maintained at that pressure for 30 minutes. During the period of maximum pressure, the switch shall be
operated for 25 cycles of operation.
4.8.19.2 Dripproof. The switch, mounted by normal means, shall be subjected to the dripproof test of
MIL-STD-108. The following details and exceptions shall apply:
(a) Quantity of water 1 gallon per station, with a minimum of 5 gallons. Water shall be evenly
distributed.
(b) Duration 5 minutes.
(c) Variation from vertical 15 degrees.
(d) Stream position 12 inches maximum above the switch.
4.8.20 Overload (see 3.23). Switches shall be subjected to 50 make-and-break cycles of operation at
a rate of 5 to 6 cycles per minute while carrying 150 percent rated resistive current at the lowest dc
voltage specified (see 3.1). The duty cycle shall be approximately 50 percent on and 50 percent off. The
switches shall be electrically and mechanically operated at the conclusion of the test.
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