Troubleshooting

If the Inverter and motor do not operate correctly due to parameter setting errors, faulty wiring, etc., use this section as a reference and take appropriate measures. Refer to the Protective and Diagnostic Functions section if a fault is displayed.
Parameters Cannot Be Set

- Problem: The display does not change when a key is pressed.
- Probable Cause: Initial settings mode cannot be entered during operation.
+ Correction: Turn OFF the Inverter and then make the settings.
- Problem: Nothing is displayed on the Digital Operator.
- Probable Cause: Cannot be determined. There is an internal circuit fault.
+ Correction: If the fault persists even after the power has been turned OFF and back ON, then replace the Inverter.

The Motor Does Not Operate

- Problem: The motor does not operate with input through the control circuit terminals.
- Probable Cause: PLC is not selected in the operation command selection (P10).
+ Correction: If "Key" (Digital Operator keys) is selected for the operation command selection (P10), operations cannot be specified from the control circuit terminals. Select PLC in the operation command selection (P10).
- Probable Cause: The wiring of the control circuit terminals of the Inverter is incorrect.
+ Correction: The Inverter cannot check the input signal if the input line of the control circuit terminals is incorrectly wired. Refer to the Wiring Control Circuit Terminals section and check that the terminals are wired according to the correct wiring method.
- Problem: The motor stops during acceleration/deceleration or when a load is connected.
- Probable Cause: The load may be too big.
+ Correction: The 3G3JE has a stall prevention function and automatic torque boost function, but the motor responsiveness limit may be exceeded if acceleration is too rapid or if the load is too big. Lengthen the acceleration time or reduce the load. Also, consider increasing the motor capacity.
- Problem: The motor operates at a frequency lower than the frequency reference.
- Probable Cause: The load may be too big.
+ Correction: The overcurrent protection may operate when the output current exceeds 150% of the Inverter's rated current, lowering the output frequency. Reduce the load.

Additional Notes

    The stall prevention function has operated during acceleration. The acceleration time is automatically increased to make tripping less likely to occur due to overcurrent during acceleration.
    The stall prevention function has operated during deceleration. The deceleration time is automatically increased to make tripping less likely to occur due to overvoltages during deceleration.

Overcurrent (e02)

- Description: The momentary overcurrent (250% of rated output current) was exceeded. The overload rated current (150% of rated output current for 1 min) was detected.
- Probable Cause: A short-circuit or ground fault has occurred at the Inverter output. A fault has occurred in the machine. The motor capacity is too large for the Inverter. The Inverter capacity is insufficient. The magnetic contactor on the output side of the Inverter has been opened and closed. The acceleration/deceleration time is too short. The output circuit of the Inverter is damaged. The load is too large.
+ Correction: Check and correct the motor power cable. Correct the machine fault. Reduce the motor capacity to the maximum permissible motor capacity or less. Increase the Inverter capacity. Rearrange the sequence so that the magnetic contactor will not open or close while the Inverter is outputting a current. Increase the acceleration/deceleration time. Replace the Inverter. Reduce the load.

Motor Overload (e03)

- Description: The electronic thermal relay actuated the motor overload protective function.
- Probable Cause: The load is too large. The acceleration/deceleration time is too short. The value in P01 for rated motor current is incorrect. The Inverter is driving more than one motor.
+ Correction: Reduce the load. Increase the motor capacity. Increase the acceleration/deceleration time. Check the motor nameplate and set P01 to the rated current. Disable the motor overload detection function and install a thermal relay for each of the motors. The motor overload detection function is disabled by setting P01 to 0.0.

Overvoltage (e04)

- Description: The main circuit DC voltage reached the overvoltage detection level (410 V DC min.) during Inverter operation.
- Probable Cause: The deceleration time is too short. The power supply voltage is too high. There is excessive regenerative energy due to overshooting at the time of acceleration.
+ Correction: Increase the deceleration time. Decrease the voltage to within specifications. Suppress the overshooting as much as possible.