4. Schneider Electric PX 250kW and 500kW
Schneider Electric's latest Symmetra PX 250kW and 500kW three-phase UPSes this year received a new firmware update, giving the units a new ECO (economical operation) mode that can deliver up to 99 percent power efficiency. ECO mode also supports synchronization to an external AC source, the ability to maintain full protection during maintenance procedures, as well as remote display applications. The PX family now also features Energy Star qualification.