UL 1778

Replace this clause of the RD with the following: 1.1.1 Equipment covered by this standard This Standard applies to UPS, whose primary function for this Standard is to ensure continuity of an alternating power source. The UPS may also serve to improve the quality of the power source by keeping it within specified characteristics. This Standard is applicable to movable, stationary, fixed, and built-in UPS for distribution systems up to 600 V AC.