Figure 2-10: Path Of Current Through The Ups In Energy Saver System - Eaton 93PR Installation And Operation Manual

Mode and remains in that mode until the available UPM power larger than the load and the UPS
is back in double conversion.
In an external parallel redundant system, each one UPS can be isolated from the system for
service while the remaining UPSs support the load in double conversion.
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". Basic surge protection and noise 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 seamles to the critical
loads.
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 upto 99% when
supplying 20-100% nominal load, reducing energy losses by up to 80%.

Figure 2-10: Path of current through the UPS in Energy Saver System

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