The purpose of this document is to provide guidance for demonstrating the qualification of Class equipment including components or equipment of any interface whose failure could adversely affect the performance of Class 1E systems and electronic equipment. Qualification required in IEEE Std 279-1971 (ANSI N42.7-1972), Criteria for Protection Systems for Nuclear Power Generating Stations and IEEE Std 308-1971, Criteria for Class 1E Power Systems for Nuclear Power Generating Stations can be demonstrated by using the guidance provided in this document. The qualification methods described shall be used for qualifying equipment and for updating qualification, following modifications. Other qualification guides for specific electric equipment or test methods (for example, IEEE Std 344-1971, Guide for Seismic Qualification of Class 1E Electric Equipment for Nuclear Power Generating Stations) will present specific requirements and should be used to supplement this document.