Eaton 93PR - Figure 2-5: Path of Current through the UPS in Energy Saver System

Eaton 93PR 500 kW UPS
User's and Installation Guide 13
Energy Saver System Mode
In ESS mode the UPS safely provides mains current directly to the load when the input is within the
acceptable limits by its voltage and frequency. The UPS status indicated on the display is “Unit Online ESS”,
and the UPM status is “Active”. Surge protection and some filtering is also provided, ensuring that clean
power is delivered to the load equipment. Should there be any disturbances detected in the incoming power,
the UPS switches to double conversion and continues to supply the critical load through its inverter. In case
of a complete utility outage or if input power is outside the tolerances of the system, the UPS transfers to
Battery Mode and continues to supply conditioned, clean power to the critical load.
When operating in ESS, the UPS superior detection and control algorithms continuously monitor
incoming power quality and allow the fast engagement of power converters. Typical transition time to double
conversion is less than 2 milliseconds, which is practically seamless.
When power conditions are within acceptable limits, the UPS operates as a high-efficiency, energy
saving system — providing surge protection for IT equipment and ensuring clean power is delivered to the
facility. Energy Saver System increases system efficiency to 99 % when supplying 20-100 % nominal load,
reducing energy losses by up to 80 %.
Internal relay contacts
Figure 2-5: Path of current through the UPS in Energy Saver System