This standard is applicable to electrical items including components or equipment of any interface whose failure could adversely affect the performance of the safety system. It is also applicable to non-electrical interfaces associated with a safety function. It describes the basic requirements for qualifying the above items. The requirements presented include the principles, procedures and methods of qualification. These qualification requirements, when met, will confirm the adequacy of the protection system equipment design to perform its function. Where qualifications is required by other IEC standards or recommendations for nuclear power generating stations, this can be demonstrated by using the guidance provided in this standard.