Specifies requirements for gas-insulated metal-enclosed switchgear in which the insulation is obtained, at least partly, by an insulating gas other than air at atmospheric pressure, for alternating current of rated voltages of 72.5 kV and above, for indoor and outdoor installation, and for service frequencies up to and including 60 Hz. For the purpose of this standard the term 'switchgear' is used for 'gas-insulated metal-enclosed switchgear'.