Applicable Systems
VF-AS1
Symptoms
The VF-AS1 reports an under-torque fault. The motor torque dropped below the configured under-torque detection level.
Possible Causes
- Mechanical load suddenly reduced or disconnected
- Belt or coupling break causing loss of load torque
- Under-torque detection level set too high for the application
Troubleshooting Steps
- Step 1: Check the mechanical load and coupling for disconnection
Load is properly connected - Step 2: Verify the under-torque detection level is appropriate
Detection level matches the normal operating torque - Step 3: Reduce the under-torque level if it is set too high
Level is set below normal operating torque
How to Reset
To reset: Restore the load torque above the level, then reset.
Source: Toshiba VF-AS1 Inverter Manual, Toshiba Mitsubishi-Electric Industrial Systems
Category: PLC & VFD