Cause : Low frequency overload protection comes when the drive operates at a frequency below 15 Hz, and output current is too large.

The oL3 fault in Delta drive indicates an Low frequency overload protection. This means the motor is drawing more current than the drive is rated for.

1. Enhance the heat dissipation capacity for the cabinet.
2. Lower the carrier frequency.
3. Decrease the voltage settings that correspond to frequency below 15 Hz in the V/F curve.
4. Replace the drive with a larger power model.