When operating in the ESS mode, the UPS's superior detection and control
algorithms continuously monitor the incoming power quality and allow fast
engagement of the power converters. Typical transition time to the double
conversion mode is less than 2 milliseconds, which is practically seamless.
When the power conditions are within acceptable limits, the UPS operates as a
high efficiency, energy-saving system, providing surge protection for IT
equipment and making sure that clean power is delivered to the facility. The
energy saver system increases system efficiency up to 99 % when supplying 20-
100% of nominal load, reducing energy losses by up to 80%.
3.3.2
Stored energy and battery mode
When running normally in the double conversion or ESS mode, the UPS
automatically transfers to supply the load from batteries or some other stored
energy source if a utility power outage occurs, or if the utility power does not
conform to the specified parameters. The UPS status indicated on the display is
On Battery
, and the UPM status is
Active
. In the battery mode, the battery
provides emergency DC power, which is converted to regulated output power by
the inverter.
Figure 6: Path of current through the UPS in the battery mode
shows the path of
electrical power through the UPS system when operating in the battery mode.
Figure 6: Path of current through the UPS in the battery mode
A
Static switch
1
Bypass input
Main power flow
B
Rectifier
2
Rectifier input
Energized
© Eaton Corporation plc 2020. All rights reserved.
Revision: 006
Document ID: P-164000493
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Eaton 91PS/93PS UPS 8–40 kW
User’s and Installation Guide