IEC/IEEE 60780-323:2016 describes the basic requirements for qualifying electrical equipment important to safety and interfaces (electrical and mechanical) that are to be used in nuclear facilities. The principles, methods, and procedures described are intended to be used for qualifying equipment, maintaining and extending qualification, and updating qualification, as required, if the equipment is modified. The qualification requirements in this standard, when met, demonstrate and document the ability of equipment to perform safety function(s) under applicable service conditions, including design basis events and certain design extension conditions, and reduce the risk of environmentally induced common-cause equipment failure. This new edition includes the following main changes with respect to the previous edition IEC 60780:1998 harmonizes in a unique standard qualification practices formerly given by IEC 60780:1998 and IEEE 323:2003 on initial qualification, takes into account the need to reassess and extend the qualified life of electrical equipment regarding projects to extend the operating life of nuclear facilities.