
Fault
code
Fault descriptions
Possible reasons
Troubleshooting
Abnormal supply voltage
Check the power supply
The driver is restarted with a
rotating motor
Start after setting as DC braking,
or rotational
Too short Dec time
Prolong the Dec time
Abnormal of supply voltage
Check the power supply
OU1(3)
Over voltage in
constant-speed
Abnormal of supply voltage
Check the power supply
Too short Acc time
Prolong the Acc time
VFD power is too small
Select a higher power drive
V/F curve is not suitable
Adjust V/F curve or torque boost
IGBT module damaged
Contact suppliers for service
Too short Dec time
Prolong the Dec time
VFD power is too small
Select a higher power drive
IGBT module damaged
Contact suppliers for service
Low grid voltage
Check the power supply
Sudden change or abnormal of
load
Check the load or reduce the
change of the load
VFD power is too small
Select a higher power drive
IGBT module damaged
Contact suppliers for service
Too short Acc time
Prolong the Acc time
VFD power is too small
Select a higher power drive
V/F curve is not suitable
Adjust V/F curve or torque boost
Too short Dec time
Prolong the Dec time
VFD power is too small
Select a higher power drive
Low grid voltage
Check the power supply
Sudden change or abnormal of
load
Check the load or reduce the
change of the load
VFD power is too small
Select a higher power drive
VFD output shorted or grounded
Check motor wiring
VFD instantaneous overcurrent
Refer to overcurrent
countermeasures
The control board is abnormal or
has serious interference
Contact suppliers for service
Damaged power device
Contact suppliers for service
OU(11)
Overvoltage during
shutdown
Abnormal input voltage
Check the power supply voltage
Power supply voltage is too high
Check if the power supply voltage
is too high
Sudden change or abnormal of
load
Check the load or reduce the
change of the load
Abnormal input voltage
Check the power supply voltage
Contactor does not pick up
Contact suppliers for service
Ambient temperature is too high
Improve the environment
Small space around the VFD
Adjust space
Air duct blocked
Clean and unclog airways
Cooling fan does not run
Check the fan's power supply and
the fan itself
OCC2(5)
Hardware Over-current in
Dec process
OCC3(6)
Hardware Over-current in
constant speed
OCS1(7)
Hardware Over-current in
Acc process
Fault code
Over voltage in
Acc process
Over voltage in
Dec process
Hardware Over-current in
Acc process
OU1(1)
OU1(2)
OCC1(4)
Hardware Over-current in
Dec process
OCS3(9)
Hardware Over-current in
constant speed
EFO(10)
Power module failure
OCS2(8)
OU3(12)
Over voltage in
constant-speed
LU(13)
Undervoltage
OH(14)
Overheat
2
1