MIL-DTL-26126 Relays, Electrical, Overvoltage, Dc, General Specification ForThis specification covers the general requirements for dc overvoltage sensing relays for use in electrical applications. Relays covered by this specification are capable of meeting the electrical and environmental requirements when mounted directly to the structure of aircraft, missile, spacecraft, ship, and other primary vehicles or in ground support and shipboard equipment.

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MIL-DTL-26126C

lead finish is acceptable, provided that lead content is at least 3 percent. Zinc plating and cadmium

plating are prohibited internally and externally.

3.5 Performance.

3.5.1 Dielectric withstanding voltage. When tested as specified in 4.6.2, relays shall withstand the test

voltage specified without damage, and there shall be no leakage current in excess of 1.0 milliampere (mA)

nor evidence of damage due to arcing (air discharge), flashover (surface discharge), or insulation

breakdown (puncture discharge).

3.5.2 Calibration.

3.5.2.1 Pickup voltage. When relays are tested as specified in 4.6.3.1, the pickup voltage shall be

within the specified voltage limits (see 3.1).

3.5.2.2 Time-voltage characteristics. When tested as specified in 4.6.3.2, the time voltage

characteristics shall be within the limits of figure 1 at each of the specified voltages.

3.5.3 Endurance. Relays shall be cycled with contacts loaded in accordance with 4.6.4. After the

tests, the fuse shall be tested for continuity. A blown fuse is considered a relay failure. After the test, the

relay shall meet the calibration requirements specified in 3.5.2.

3.5.4 Overload. When relays are tested as specified in 4.6.5, they shall not be damaged. After the

test, the relays shall meet the pickup voltage requirements specified in 3.5.2.1. The input voltage drop

shall not exceed 7 percent during the load period.

3.5.5 High temperature. When tested as specified in 4.6.6, the relays shall meet the calibration

requirements specified in 3.5.2. During high temperature testing, no solder joint connected to a resistor

within the relay shall attain a temperature within 75�C of the softening temperature of solder.

3.5.6 Low temperature. When tested as specified in 4.6.7, the relays shall meet the requirements of

4.6.3.

3.5.7 Vibration.

3.5.7.1 Vibration (endurance). When tested as specified in 4.6.8.1, with the relay sensing circuit

energized with 29 V dc, the contacts shall not close for more than 10 microseconds. When tested with the

relay sensing circuit de-energized, the relay contacts shall not close for more than 10 microseconds.

There shall be no damage to or malfunction of the relay during the test. Following this test, the relay shall

meet the calibration requirements specified in 3.5.2.

3.5.7.2 Vibration (calibration). When tested as specified in 4.6.8.2, the relay shall meet the

requirements of figure 2. Following the test, the relay shall meet the pickup voltage requirements

specified in 3.5.2.1.

3.5.8 Low-temperature altitude. When tested as specified in 4.6.9 (see figure 2), immediately after the

2-minute coil energization, the relay shall meet the calibration requirements specified in 3.5.2.