Eaton 93E G2 100/100 User And Installation Manual page 24

Eaton 93E Generation 2 UPS 100-200 kVA
(380/400/415V)
Figure 5. Path of current through the UPS in the stored energy mode
A Static
switch
B Rectifier
C Inverter
D Battery con-
verter
E Battery
During a utility power failure, the rectifier no longer has an AC utility source from
which to supply the DC output voltage required to support the inverter. The input
contactor opens and the battery instantaneously supplies energy to the battery
converter. The converter boosts the voltage so that the inverter can support the
customer's load without interruption. If bypass is common with the rectifier input,
the backfeed protection contactor also opens. The opening of the input and the
internal backfeed protection contactors prevent system voltages from bleeding
backwards through the static switch and rectifier snubber components to the
utility source.
If the input power fails to return or is not within the acceptance windows required
for normal operation, the battery continues discharging until a DC voltage level
is reached where the inverter output can no longer support the connected loads.
When this event occurs, the UPS issues another set of audible and visual
alarms indicating Shutdown imminent. Unless the rectifier has a valid AC input
soon, the output can be supported for a maximum of two minutes before the
©
Eaton Corporation plc 2019. All rights reserved.
1 Bypass in-
put
2 Rectifier in-
put
3 Output
4 Battery
breaker
Closed
Revision: 002
User's and installation guide
Main power flow
Energized
De-energized
Trickle current
Open
Document ID: P-164000848 24 (118)