Applicable Systems
VF-AS1
Symptoms
The VF-AS1 reports a motor overload fault. The motor thermal model calculated excessive heating based on current and time, tripping to protect the motor.
Possible Causes
- Motor load torque exceeds the motor rated capacity
- Duty cycle exceeding the motor thermal class rating
- Motor cooling insufficient due to blocked ventilation or fan failure
Troubleshooting Steps
- Step 1: Check the motor load and verify it is within the rated capacity
Load torque is within the motor rating - Step 2: Inspect the motor cooling fan and ventilation for blockage
Motor cooling is adequate and unobstructed - Step 3: Set the motor rated current parameter to match the nameplate value
Motor thermal model matches the actual motor
How to Reset
To reset: Allow the motor to cool and resolve the overload, then reset.
Source: Toshiba VF-AS1 Inverter Manual, Toshiba Mitsubishi-Electric Industrial Systems
Category: PLC & VFD