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MIL-PRF-24236 Switches, Thermostatic, \(Metallic And Bimetallic\), General Specification ForThis specification covers the general requirements for metallic-element actuated, thermostatic switches intended primarily for use in electrical and electronic equipment, in alternating current \(ac\) and direct current \(dc\) applications, where temperature protection, overheat detection, or accurate temperature control is required. The operating temperatures and operating temperature ranges of switches are covered by this specification \(see 3.1 and 6.2.2\).

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MIL-PRF-24236D

4.6.8 Dielectric withstanding voltage (see 3.13). Switches shall be tested in accordance with 4.6.8.1 and, when

applicable (see 3.1 and 6.2.2), in accordance with 4.6.8.2. This test shall be performed with the switch in normal

position, and shall then be repeated for other operating positions.

4.6.8.1 At atmospheric pressure. Switches shall be tested in accordance with method 301 of MIL-STD-202. The

following details shall apply:

(a)

Magnitude of test voltage - 1,000 volts plus twice the working voltage for initial test and 1,000 volts

for subsequent tests.

(b)

Nature of potential - AC.

(c)

Duration of application of test voltage - 1 minute for qualification and group B tests: 5 seconds for

all other tests, at 20 percent higher voltage.

(d)

Points of application of test voltage - Between all terminals and ground.

(e)

Maximum leakage current - 500 microamperes.

(f)

Examination after test - Switches shall be examined for evidence of arcing and flashover.

4.6.8.2 At reduced barometric pressure. Switches designed for operation above 10,000 feet shall be tested as

specified in 4.6.8.1, and in accordance with method 105 of MIL-STD-202. The following details and exception shall

apply:

(a)

Method of mounting - Normal mounting means.

(b)

Test condition - C or D, as applicable.

Test voltage - 500 volts, unless otherwise specified (see 3.1 and 6.2.2).

(c)

4.6.9 Insulation resistance (see 3.14). Switches shall be tested in accordance with method 302 of MIL-STD-202.

The following details shall apply:

(a)

Test condition - B.

(b)

Points of measurement - Between all terminals and frame or ground.

4.6.10 Contact resistance (see 3.15). Switch contacts shall be tested in accordance with method 307 of

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

(a)

Measurements - Between the terminals of the contacts of the same pole forming a switching

circuit: for all poles in a switch at each of the temperature settings; between mated contacts for all

poles.

Test current - 0.1 ampere +.005.

(b)

Test voltage - 6 � 1/2 volts dc.

(c)

(d)

Number of activations prior to measurement - Not applicable.

(e)

Number of test activations - Three.

(f)

Number of measurements per activation - One reading after each thermal actuation.

4.6.11 Thermal shock (see 3.16). Switches shall be tested in accordance with method 107 of MIL-STD-202. The

following details and exception shall apply:

(a)

Test condition - B.

(b)

Measurement before and after cycling - Not applicable.

Examination after test - The temperature settings shall be within the tolerances specified (see 3.1,

(c)

6.2.2, and 3.5.3).