OM226142 rev C
16
Thanks to the transfer logic integrated in the control, the load is supplied by the bypass
static switch even in case of microprocessor failure.
Overload capability:
150% continuously
200% for 1 minute
2000% for 1 cycle
2.4.1 Inverter
Æ
Emergency Line transfer
The transfer is activated only if emergency line is in tolerance (in less than 0,5 ms), for the
following reasons:
CAUSES COMMUTATION
CONDITIONS
Output short circuit
Emergency line within tolerance limits
Fault of inverter or inverter voltage out of
tolerance
Emergency line within tolerance limits
DC over-voltage/under-voltage (Inverter OFF)
Emergency line within tolerance limits
Over-temperature Emergency
line within tolerance limits
Thermal image shut down
Emergency line within tolerance limits
Forced commutation by “BYPASS SWITCH”
(test or service)
Emergency line within tolerance limits
AND synchronized inverter
2.4.2 Emergency Line
Æ
Inverter transfer
As soon as inverter is correctly working and synchronized, UPS automatically switches to
inverter in less than 1 msec. If UPS switches back and forth more than 6 times in two
minutes, an alarm will be generate, to inform the user, and UPS will be locked to
emergency line until a manual reset will clear the faulty condition.
2.5 MANUAL
BY-PASS
To safely allow maintenance and repair of the unit, UPS is provided with a manual bypass
switch.
In bypass mode all the repairing and testing activities to verify the efficiency of the whole
UPS can be carried out safely. Manual by-pass can be inserted by following the relevant
instructions. During manual by-pass operation there’s no interruption of the supply to the
load.
