Modifications reserved
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OPM_SGS_USM_M75_M75_2US_V010.doc
User Manual
SG Series 750 UL S2 & SG Series 750 T12 UL S2
4.2.5 Automatic Bypass
In normal operation, the
Load
is supplied by the
Inverter
.
When the control system detects a fault in the
Inverter
, an overload condition or a short-circuit
condition, the
Automatic Bypass
will transfer the
critical
Load
to the
Utility
without interruption.
Fig. 4.2.5-1 Block diagram Automatic Bypass
When the
Inverter
recovers, or the overload or short-circuit condition is corrected, the
Load
will be
automatically transferred back to the
Inverter
.
If the UPS is unable to return to normal mode following an automatic transfer to
Bypass mode
, an
alarm condition will be initiated.
A
Manual Bypass
(operator initiated) will not be considered as an alarm condition.
In case of parallel operation
Each unit has its own internal Bypass.
These units are continuously exchanging information, enabling all of the internal Bypass circuits in a
parallel system to operate simultaneously.
If the Inverter of a unit fails, its Bypass circuit remains available to the Parallel System.
It is excluded only if the unit is separated from the common bus by opening its output switch
Q1
.
