IEEE 420-1973

This document applies to all Class IE control switchboards (for example, main control room assemblies, auxiliary panels, local panels or racks, etc) as defined in Section 3, regardless of their application or location. It does not apply to the non-Class IE control switchboards, except as they affect the Class IE control switchboards, but recognizes that Class IE control switchboards may be adjacent to, or joined with, other non-Class IE control switchboards. This document includes, but is not necessarily limited to, design, construction, wiring practices, shipping, handling, storage, installation, testing, and quality assurance. General design practices which are not unique to Class IE control switchboards are not addressed in this document. This document applies to piping systems and Class IE equipment only as they may affect the integrity of the Class IE control switchboard.

The purpose of this document is to provide guidance for the design, manufacture and installation of Class IE control switchboards in nuclear power generating stations to conform to IEEE Std 279-1971, Criteria for Protection Systems for Nuclear Power Generating Stations, ANSI N42.7-1972 and other documents as referenced.

New IEEE Standard - Superseded.