IEEE C37.20.1-2002

This project will provide a revision of the current C37.20.1 Standard. The current revision was issued in 1993 and reaffirmed in 1998. The equipment covered by this Standard has been and continues to be a vital element of industrial, commercial, institutional and utility electrical distribution systems. Revision Standard - Superseded. Low-voltage metal-enclosed switchgear-which contains either stationary or drawout, 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 are 254V, 508V, or 635V (ac) and 300/325V, 800V, 1000V, 1200V, 1600V, or 3200V (dc). The preferred continuous current ratings of the main bus in ac designs are 1600A, 2000A, 3000A, 3200A, 4000A, or 5000A. For dc designs, the preferred ratings are 1600A, 2000A, 2500A, 3000A, 4000A, 5000A, 6000A, 8000A, 10000A, or 12000A. The switchgear may also contain associated control, instruments, metering, protective, and regulating devices as necessary. The standard deals with service conditions, ratings, temperature limitations, and classification of insulating materials, insulation (dielectric) withstand voltage requirements, test procedures, and application.