P-164000249
30-200 kW
15
Revision 2
User's and Installation Guide
2.2.1.2 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 two 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
2.2.2 Stored energy and battery mode
When running normally in double conversion or ESS mode, the UPS automatically transfers to supply
the load from batteries or other stored energy source if a utility power outage occurs, or if the utility
power does not conform to specified parameters. The UPS status indicated on the display is “On
Battery”, and the UPM status is “Active”. In battery mode, the battery provides emergency DC
power which is converted to regulated output power by the inverter.
Figure 2-6: Path of current
through the UPS in battery mode
on page 16 shows the path of electrical power through the UPS
system when operating in battery mode.
