A central power supply system (CPSS) provides battery backup during emergencies but differs in design and performance to an uninterruptible power supply (UPS). A CPSS is used to power safety critical systems within buildings to provide sufficient time for evacuation during a power outage. A UPS system provides conditioned power when the mains power supply is present and battery backup during a power outage to ensure continuos operation of IT systems in server rooms and data centres and for larger sites may be supported by a standby power generator. BS EN 50171:2021 is the European safety standard that defines the requirements for a central power supply system.
