Applicable Systems
VF-AS1
Symptoms
The VF-AS1 reports an overload fault. The thermal model calculated I2t exceeded the trip threshold indicating sustained overload.
Possible Causes
- Load torque exceeds the rated capacity
- Mechanical binding or friction increasing the load demand
- Acceleration time too short for the load inertia
Troubleshooting Steps
- Step 1: Check the mechanical load for binding, friction, or excessive torque demand
Load torque is within the rated capacity - Step 2: Increase the acceleration and deceleration times to reduce peak current
Peak current stays within the thermal model limit - Step 3: If the load genuinely requires more torque, upgrade to a larger unit
Larger unit handles the load without overload trips
How to Reset
To reset: Resolve the overload condition, wait for thermal model to reset, then restart.
Source: Toshiba VF-AS1 Inverter Manual, Toshiba Mitsubishi-Electric Industrial Systems
Category: PLC & VFD