10-2
LED display
Description
Cause
Possible solutions
Inverter faults that cannot be reset
LV
Under voltage
DC bus voltage is
lower than the UV
detection level or
the pre-charge
contactor is not
active while the
inverter is running.
190Vdc: 230V
class;
380Vdc: 460V
class;
The detection value
can be adjusted by
07-13).
The input voltage is too low.
Input phase loss.
Acceleration time set too short.
Input voltage fluctuation.
Pre-charge contactor damaged.
DC bus voltage feedback signal value not
incorrect.
Check the input voltage.
Check input wiring.
Increase acceleration time.
Check power source
Replace pre-charge contactor
Replace control board or
complete inverter.
OH
Heatsink
overheat
The temperature of
the heat sink is too
high.
Note: when OH
fault occurs three
times within five
minutes, it is
required to wait 10
minutes before
resetting the fault.
Ambient temperature too high.
cooling fan failed
Carrier frequency set too high.
Load too heavy.
Install fan or AC to cool
surroundings.
Replace cooling fan.
Reduce carrier frequency.
Reduce load / Measure output
current
OH
Heatsink
overheat
The temperature of
the heat sink is too
high.
Note: when OH
fault occurs three
times within five
minutes, it is
required to wait 10
minutes before
resetting the fault.
Ambient temperature too high.
cooling fan failed
Carrier frequency set too high.
Load too heavy.
Install fan or AC to cool
surroundings.
Replace cooling fan.
Reduce carrier frequency.
Reduce load / Measure output
current
EEPROM Fault
EEPROM fault
EEPROM malfunctioned
Contact TWMC.
CT Fault
Input voltage fault
Abnormal input voltage, too much noise or
malfunctioning control board.
Check input voltage signal and
the voltage on the control
board.