This standard applies to movable, stationary and/or fixed electronic uninterruptible power systems (UPS) that deliver single or three-phase fixed frequency a.c. output voltage not exceeding 1000V a.c. and that present, generally through a d.c. link, an energy storage system.This standard is intended to specify performance and test requirementys of a complete UPS and not of individual UPS functional units. The individual UPS functional units are dealt with in IEC publications referred to in the bibliography given in annex O that apply so far that they are not in contradiction with this standard.The primary function of the UPS covered by this standard is to e