This specification establishes general requirements for electromechanical relays with contact ratings of 270 Vdc 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 as well when used within other subsystems such as electrical load management centers or power controllers.

Classification. Relays covered by this specification shall be classified by the enclosure design as follows:

Type 1 - Unsealed

Type 2 Environmentally sealed

Type 3 Hermetically sealed