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9.2. Trouble Shooting According To Fault Indication
Problem Displayed
Possible cause
Remedy
Output short
Output short circuit
Remove all the loads. Turn off the
UPS. Check if UPS output and loads
is short circuit. Ensure short circuit is
removed before turning on again.
Over load
Over load
Check the loads and remove some
non-critical loads.
Check if some loads are failed.
Neg power fail
The load is pure
inductive and capacitive
Remove some non-critical loads.
Bypass supplies the load first, ensure
there is no overload, then turn on UPS
Over temperature
Inside temperature of
UPS is too high
Check the ventilation of UPS and the
ambient temperature
Fan fail
Fan blocked or
disconnected over time
Check the fan status
Back feed
Output voltage is
returned to input
Consult dealer
DC short
Bus short
Consult dealer.
DC over
Bus over voltage
Consult dealer.
DC under
Bus under voltage
Consult dealer.
DC unbalance
Bus unbalance
Consult dealer.
DC soft fail
Bus soft start fail
Consult dealer.
Output soft fail
Output soft start fail
Consult dealer.
Output volt low
Output volt low
Consult dealer.
Output volt high
Output volt high
Consult dealer.