GE Industrial Solutions SG Series 750 T12 UL S2 User Manual - Manual (Page 15)

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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.