A Practical Fault Tolerance Assessment for Data Centre Rotary UPS Systems

Electrical power to data hall critical loads will often be fed via an uninterruptable power supply (UPS) strings. Therefore, fault tolerance of these machines is of pivotal importance for the data centres uptime. The UPS will be in the middle of a complex electrical distribution system with reliance on other connected components for optimal performance. The data centre owners will also want to know what happens when components on the UPS power string fail and what effects this can have on critical equipment's. The goal is to minimise any negative effective on critical power and achieve 100% operational uptime. This paper investigates a rotary UPS string in terms of fault currents, electrical protection and arc flash.