Figure 4. Path of current through the UPS in the bypass mode
A Static
switch
1 Bypass in-
put
Main power flow
B Rectifier
2 Rectifier in-
put
Energized
C Inverter
3 Output
De-energized
D Battery con-
verter
4 Battery
breaker
Trickle current
E Battery
Closed
Open
In the bypass mode, the output of the system is provided with three-phase AC
power directly from the system input. While in this mode, the output of the
system is not protected from voltage or frequency fluctuations or power outages
from the source. Some power line filtering and transient protection is provided to
the load, but no active power conditioning or battery support is available to the
output of the system in the bypass mode.
The internal bypass is comprised of a solid-state, silicon-controlled rectifier
(SCR) continuous static switch, and an internal backfeed protection contactor.
The static switch is used instantaneously anytime the inverter is unable to
support the applied load. The continuous static switch is wired in series with the
backfeed protection contactor, and together they are wired in parallel with the
rectifier and inverter.
The static switch, being an electronically-controlled device, can be turned on
immediately to pick up the load from the inverter while inverter output contactor
Eaton 93E Generation 2 UPS 100-200 kVA
(380/400/415V)
User's and installation guide
©
Eaton Corporation plc 2019. All rights reserved.
Revision: 002
Document ID: P-164000848
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