This standard covers metal-enclosed interrupter switchgear assemblies containing but not limited to such devices as interrupter/switches@ selector switches@ power fuses@ control@ instrumentation and metering@ and protective equipment. It includes@ but is not specifically limited to@ equipment for the control and protection of apparatus used for distribution of electrical power. This standard is concerned with enclosed@ rather than open@ switchgear assemblies rated above 1000 V. It includes equipments that are part of primary and secondary unit substations. It does not include gas insulated substation equipments@ nor switching devices mounted integrally within a transformer enclosure. In this standard the metal-enclosed interrupter switchgear shall be called MEI switchgear.