Filter
Top Products
Chapter 6 - Troubleshooting & Maintenance
93
6.3 Fault Remedy
Protective
Function
Cause Remedy
Over Current
Protection
1) Acceleration/Deceleration time is too short compared to
the GD²of the load.
2) Load is larger than the inverter rating.
3) Inverter turns output on while motor is free running.
4) Output short or ground fault has occurred.
5) Mechanical brake of the motor is operating too fast.
6) Components of the main circuit have overheated due to
a faulty cooling fan.
1) Increase Accel/Decel time.
2) Increase inverter capacity.
3) Operate after motor has stopped.
4) Check output wiring.
5) Check mechanical brake operation.
6) Check cooling fan.
(Caution) Operating prior to correcting fault may
damage the IGBT.
Over Voltage
Protection
1) Deceleration time is too short compared to the GD²of the
load.
2) Regenerative load on inverter output.
3) Line voltage is too high.
1) Increase deceleration time.
2) Use regenerative resistor option.
3) Check line voltage.
Current Limit
Protection
(Overload
Protection)
1) Load is larger than inverter rating.
2) User selected incorrect inverter capacity.
3) User set incorrect V/F pattern.
1) Increase capacity of motor and inverter.
2) Select a correct inverter capacity.
3) Select correct V/F pattern.
Heat Sink
Overheat
1) Cooling fan is damaged or an alien substance is
inserted.
2) Cooling system has faulted.
3) Ambient temperature too high.
1) Exchange cooling fans and/or eliminate alien
substance.
2) Check for any alien substances in heat sink.
3) Keep ambient temperature under 40 °C (104 °F).
Electronic
Thermal
1) Motor has overheated.
2) Load is larger than inverter rating.
3) ETH level too low.
4) User selected incorrect inverter capacity.
5) User set incorrect V/F pattern.
6) Operating too long at low speeds.
1) Reduce load and/or running duty.
2) Increase inverter capacity.
3) Adjust ETH level to an appropriate level.
4) Select a correct inverter capacity.
5) Select a correct V/F pattern.
6) Install a cooling fan with a separate blower.
Low Voltage
Protection
1) Line voltage too low.
2) Load larger than line capacity connected to input.
(Welding machine, motor with high starting current
connected to the commercial line)
3) Damaged or faulty magnetic switch at input side of
inverter.
1) Check line voltage.
2) Increase line capacity.
3) Exchange magnetic switch.
Output Phase
Open
1) Faulty contact on the magnetic switch at the output.
2) Faulty output wiring
1) Check magnetic switch on output.
2) Check output wiring.
H/W Fault
1) Fan Fault
2) CPU Error
3) EEPROM Error
4) Ground Fault
5) NTC Damage
1) Check cooling fan.
2) Exchange inverter.
3) Exchange inverter.
4) Check inverter, motor, and wiring insulation.
5) Check NTC.
LOV (V1)
LOI (I)
Frequency Reference is Lost Eliminate cause of fault.
Inverter
Overload
1) Load is larger than inverter rating.
2) User selected incorrect inverter capacity.
1) Increase motor and/or inverter capacity.
2) Select correct inverter capacity.