Liebert UPS System User Manual page 91

No.1 Fault description
30 Rectifier fan fails
Rectifier contactor
31
abnormal
Auxiliary contactor
32
abnormal
Auxiliary power supply
33
1 fails
34 Rectifier over current
35 Inverter asynchronous
36 Inverter fails
Inverter heatsink over
137
temperature
38 Inverter fan fails
39 Inverter SCR fails
Auxiliary power supply
40
2 fails
41 Inverter over current
Shutdown due to low
42
bus voltage
Output transformer
43
over temperature
44 overload
Overload exceeds
45
normal time
46 Output fuse blows up
AC output
47
voltage
48 Output surge current
Chapter 7 Troubleshooting
Reason
Rectifier fan is abnormal
Rectifier contactor can't be closed or
opened normally
Auxiliary contactor abnormal can't
be closed or opened normally
At least one auxiliary power supply
fails
The IGBT of rectifier has over
current resulting in the shut down of
rectifier.
Inverter is asynchronous
bypass
Inverter output fails and shuts down
Inverter heatsink temperature is too
high
Inverter fan is abnormal
Inverter SCR fails and has no
output. UPS shuts down
At least one auxiliary power supply
fails
The IGBT of inverter has over
current resulting in the shut down of
inverter.
DC bus voltage is too low resulting
in the shutdown of inverter
Output transformer temperature is
too high
Load is too heavy
Over load occurs in inverter mode,
transfers to bypass mode
Output fuse blows
over Output over voltage
Surge current occurs in bypass
mode, the system shutdown
Actions to be taken
Replace the fan in time and the UPS can
recover automatically
Notify the service dept for repairing
Notify the service dept for repairing
Notify the service dept for repairing
Notify the service dept for repairing
Check if the bypass is normal. The fault
with
alarm stops
bypass recovers normal
Notify the service dept for repairing
The UPS can recover automatically.
Check the environment and ventilation
Replace the fan in time and the UPS can
recover automatically
Notify the service dept for repairing
Notify the service dept for repairing
Restart the inverter, if the fault can't be
cleared, notify the service dept for
repairing.
Check whether there is fault in rectifier
side, if no, then check whether overload
occurs. Restart after clearing the fault.
Auto recovery, ambient and ventilation of
UPS should be checked.
Disconnect unnecessary load and ensure
the safety.
If the load decreases after 5 minutes, the
system will back to inverter mode
Notify the service dept for repairing
Notify the service dept for repairing
Avoid applying big load abruptly and short
circuit
85
automatically after the