Traditionally, data center managers and facilities managers could choose from three UPS topologies: standby, line-interactive and double-conversion-offering widely varying levels of efficiency, performance and protection.

The latest generation of double-conversion UPSs offers unique multi-mode capabilities. The UPS operates in a very high-efficiency mode unless power conditions warrant a switch to the higher protective level typical of double-conversion mode.

This white paper describes how various UPS topologies work and looks at the impact of operating mode on five key factors of UPS performance:

Maintaining voltage within tolerances

Transferring among modes without locking up IT equipment

Transitioning gracefully to and from generator power

Reliability and availability

Energy efficiency