Figure 5. 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 static bypass consists of a solid-state, silicon-controlled rectifier (SCR)
static switch (STSW) and a backfeed protection isolation device K5. The static
switch is rated as a continuous-duty device that is used anytime the inverter is
unable to support the applied load. The static switch is wired in series with the
backfeed protection. As the static switch is an electronically-controlled device, it
can be turned on immediately to pick up the load from the inverter without
interruption. The backfeed protection is normally always closed, ready to
support the static switch unless the bypass input source becomes unavailable.
Eaton 93PM UPS 30–200 kVA
User's and installation guide
©
Eaton Corporation plc 2017. All rights reserved. Revision: 005 Document ID: P-164000249 26 (126)
To Next Page
Loading...
