Figure 5: Path of current through the UPS in the Energy Saver System mode
A
Static switch
1
Bypass input
Main power flow
B
Rectifier
2
Rectifier input
Energized
C Inverter
3
Output
De-energized
D Battery
converter
4
Battery breaker
Trickle current
E
Battery
Closed
Open
In the 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, making sure that
clean power is delivered to the load equipment. In case any disturbances are
detected in the incoming power, the UPS switches to the double conversion
mode and continues to supply the critical load through its inverter. In case of a
complete utility outage or if the input power is outside the tolerances of the
system, the UPS transfers to the battery mode and continues to supply
conditioned, clean power to the critical load.
© 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