Revision Standard - Superseded. This IEEE Standards product is part of the C37 family on Switchgear, Substations and Protective Relays. Low-voltage metal-enclosed switchgear, which can contain either stationary or draw out, manually or electrically operated low-voltage ac or dc power circuit breakers in individual grounded metal compartments, in three-pole, two-pole, or single-pole construction is covered. Rated maximum voltage levels can be 254 V, 508 V, or 635 Vac and 300/325 Vm 800V, 1000 V, 1600V, or 3200 Vdc. The continuous current ratings of the main bus in ac designs can be 1600 A, 2000 A, 2500 A, 4000 A, 6000 A, 8000 A, 10 000 A, or 12 000 A. The switchgear can also contain associated control, instruments, metering, protective, and regulating devices as necessary. The standard deals with service conditions, rating, temperature limitations, and classification of insulating materials, insulation (dielectric) withstand voltage requirements, test procedures, and application.