MIL-DTL-28827 Switches, Thermostatic, \(Volatile Liquid\), Hermetically Sealed, General Specification ForThis specification covers the general requirements for hermetically sealed volatile liquid thermostatic switches intended primarily for use in equipment requiring rapid temperature response. The operating temperatures and operating temperature ranges of switches covered by this specification are as specified \(see 3.1 and 6.1.2\).

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MIL-DTL-28827C

4.7.14.2 Solder-lug and wire load terminals. Switches shall be tested in accordance with method 211

of MIL-STD-202. The following details and exceptions shall apply:

a. Test condition letter � A.

b. Applied force

1. Solder lug � 9 pounds.

2. Wire-lead � 15 pounds, unless otherwise specified (see 3.1).

c. Direction of force � Force shall be applied along three mutually perpendicular axes of the

terminal, one direction of which shall be the one most likely to cause failure, unless otherwise

specified (see 3.1).

4.7.15 Short circuit (when specified, see 3.1) (see 3.19). Switches shall be inserted in a circuit which

has been calibrated using a dummy switch, and which will supply a current equal to 15 times the rated

resistive load at the lowest dc voltage specified (see 3.1), when monitored through the switch contacts.

Each switch shall be connected in series, by 1-foot lengths of wire, to a thermal-type circuit breaker or a

fuse in accordance with figure 2 and table VI. A circuit breaker shall be used for switches having a rated

resistive load of 5 amperes or greater, and a fuse for switches having free air as listed in SAE-AS50861

and table VI, determined by the rated resistive load of the switch (see 3.1). If the rated load of the switch

does not coincide with a wire size, the next larger wire size shall be used. The terminals shall be in

accordance with SAE-AS7928. The circuit breaker shall be in accordance with SAE-AS58091 and table

VI, and fuses shall be in accordance with and table VI, and of the same current rating as the resistive

current rating of the switch. Calibration shall be made without the circuit breaker (or fuse), test switch, or

switch leads in the circuit. With both the switch under test and the circuit breaker in a closed position, and

with switch S2 in the position shown on figure 2, the circuit shall be closed manually by switch S1. A

minimum of 2 minutes shall elapse between the successive closings of the switch. The test shall be

conducted five times.

FIGURE 2. Circuit diagram for short circuit test.