Applies to uninterruptable power system (UPS) meant to be installed in any operator accessible area. Specifies requirements to ensure safety for the operator and layman who may come into contact with the equipment and, where specifically stated, for service personnel. Applies to movable, stationary, fixed and built in UPS for distribution systems up to 1000 V a.c. Does not cover: UPS meant to be installed in separated electrical installations; d.c. supplied electronic ballasts; UPS based on rotating machines. Includes the following sections; fundamental design requirements; physical requirements; thermal and electrical requirements. Also gives detailed definitions and annexes.