Liebert UPS System User Manual
Page 91
Chapter 7 Troubleshooting
85
No.1
Fault description
Reason
Actions to be taken
30 Rectifier
fan
fails
Rectifier fan is abnormal
Replace the fan in time and the UPS can
recover automatically
31
Rectifier contactor
abnormal
Rectifier contactor can’t be closed or
opened normally
Notify the service dept for repairing
32
Auxiliary contactor
abnormal
Auxiliary contactor abnormal can’t
be closed or opened normally
Notify the service dept for repairing
33
Auxiliary power supply
1 fails
At least one auxiliary power supply
fails
Notify the service dept for repairing
34
Rectifier over current
The IGBT of rectifier has over
current resulting in the shut down of
rectifier.
Notify the service dept for repairing
35 Inverter
asynchronous
Inverter is asynchronous with
bypass
Check if the bypass is normal. The fault
alarm stops automatically after the
bypass recovers normal
36
Inverter fails
Inverter output fails and shuts down Notify the service dept for repairing
137
Inverter heatsink over
temperature
Inverter heatsink temperature is too
high
The UPS can recover automatically.
Check the environment and ventilation
38
Inverter fan fails
Inverter fan is abnormal
Replace the fan in time and the UPS can
recover automatically
39 Inverter
SCR
fails
Inverter SCR fails and has no
output. UPS shuts down
Notify the service dept for repairing
40
Auxiliary power supply
2 fails
At least one auxiliary power supply
fails
Notify the service dept for repairing
41 Inverter
over
current
The IGBT of inverter has over
current resulting in the shut down of
inverter.
Restart the inverter, if the fault can’t be
cleared, notify the service dept for
repairing.
42
Shutdown due to low
bus voltage
DC bus voltage is too low resulting
in the shutdown of inverter
Check whether there is fault in rectifier
side, if no, then check whether overload
occurs. Restart after clearing the fault.
43
Output transformer
over temperature
Output transformer temperature is
too high
Auto recovery, ambient and ventilation of
UPS should be checked.
44 overload
Load is too heavy
Disconnect unnecessary load and ensure
the safety.
45
Overload exceeds
normal time
Over load occurs in inverter mode,
transfers to bypass mode
If the load decreases after 5 minutes, the
system will back to inverter mode
46
Output fuse blows up Output fuse blows
Notify the service dept for repairing
47
AC output over
voltage
Output over voltage
Notify the service dept for repairing
48 Output
surge
current
Surge current occurs in bypass
mode, the system shutdown
Avoid applying big load abruptly and short
circuit