Basic principles, requirements, and methods for qualifying Class 1E protective relays and auxiliaries in nuclear power generating stations, including digital and analog devices, but excluding devices located inside the primary containment, are covered in this standard.

This standard covers the qualification of Class 1E protective relays and auxiliaries to be used outside the primary containment in nuclear power generating stations and other nuclear facilities. Protective relays and auxiliaries located inside the primary containment in a nuclear power generating station present special conditions beyond the scope of this document.

This standard: a) Defines specific qualification methods for Class 1E protective relays and auxiliaries in accordance with the more general qualification requirements of IEC/IEEE 60780-323. b) Provides guidance in establishing a program for demonstrating the design adequacy of Class 1E protective relays and auxiliaries in nuclear power generating stations and other nuclear facilities.