This document specifies the performance and the functional characteristics of the low voltage static uninterruptible power supply (SUPS) systems in a nuclear power plant (NPP) and, when applicable, in nuclear facilities in general. An uninterruptible power supply (UPS) is an electrical equipment which draws electrical energy from a source, stores it, and maintains the supply in a specified form by means inside the equipment to output terminals. A SUPS has no rotating parts to perform its functions. The specific design requirements for the components of the power supply system are covered by IEC standards and other standards listed in the normative references and. Otherwise, specific component-level design requirements are otherwise outside the scope of this document.