IEC 62310 consists of three parts and applies to free standing a.c. static transfer systems (STS) intended to ensure the continuity of power to load by automatically or manually controlled transfer, with or without interruption, from two or several a.c. independent sources. This part of IEC 62310 concerns general and safety requirements. See IEC 62310-2 for electromagnetic compatibility (EMC) and IEC 62310-3 for the method of specifying performance and test requirements. This part of IEC 62310 is intended to reduce the risk of fire, electric shock, or injury to persons from installed equipment subject to installing, operating, and maintaining the equipment