MIL-PRF-28776 Relays, Hybrid, Established Reliability, General Specification ForThis specification establishes the general requirements for relays that use a combination of solid state circuit input elements functioning with an electro-mechanical relay that performs the switching functions associated with control system applications \(see 6.1\). These relays are designed to operate in low and medium power switching circuits with contact ratings up to 1 ampere alternating current \(ac\) or direct current \(dc\). The failure rate level is established at a confidence level of 90 percent for qualification and 60 percent for maintenance of qualification based on 100,000 cycles at +125┬░C under rated load conditions specified herein. Excludes time delay relays. CAUTION: The use of any coil voltage less than the rated coil voltage will compromise the operation of the relay. CAUTION: Pick-up, hold, and dropout voltages are for test purposes only and are not to be used as design criteria. For additional application and caution information, see 6.1.

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MIL-PRF-28776F

TABLE VIII. Test details for dielectric withstanding voltage.

Points of application

Test voltage

Between case, frame, or enclosure and between all

contacts in the energized and de-energized positions

Between case, frame, or enclosure and coil

1,000 �5 percent volts ac plus

Between all contacts and coil

twice rated voltage or the

Between open contacts in the energized and de-

specified value �5 percent

energized positions

Between contact poles in the energized and de-

energized positions (applicable to multipole relays)

4.8.6.2 At reduced barometric pressure. Relays shall be tested in accordance with method 105 of MIL-STD-202.

The following details shall apply:

Method of mounting: Normal mounting means.

Test condition: C.

Tests during subjection to reduced pressure: As specified in 4.8.6.1, unless otherwise specified (see 3.1),

except test voltage shall be 350 volts.

Points of application of test voltage: All terminals to case.

Duration of application: 60 seconds minimum for qualification and groups B and C tests.

Attributes data is acceptable.

4.8.7 Electrical characteristics (see 3.12).

4.8.7.1 Static contact resistance or contact voltage drop (see 3.12.1). The static contact resistance or static

contact voltage drop shall be required for each pair of contacts. If both contact voltage drop and static contact

resistance are specified in the documents the manufacturer has the choice of which to run for the contacts. However,

each contact must be tested.

4.8.7.1.1 Static contact resistance (see 3.12.1). Relays shall be tested in accordance with method 307 of MIL-

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

Method of connection: The point of measurement shall be on leads external to the case. Suitable jigs and

fixtures shall be used.

Test load: Test current shall be 100 mA at a voltage equal to or below rated voltage, except those rated for

low level. See 6.1.1 for low level voltage rating. For low level, the current shall be 10 mA maximum. (dc or

peak ac).

Post test current: Unless life tests are specified in the grouping, load current and voltage shall be 100 mA

maximum at a voltage equal to or below rated voltage. When life tests are specified in the grouping, the

same current at a maximum of rated voltage as the life test, or 100mA maximum at 28vdc maximum, shall

be used.