Cause : Converter transistor protection thermal operation (electronic thermal) comes when current flowing in the module of the regeneration converter is less than the overcurrent shutoff level and exceeds the specified value, electronic thermal relay activates for protection and the inverter output is stopped.

1. Check the motor for use under overload. (excess regeneration amount)
2. Check that the thyristor load does not exist in the same power supply system.
3. Reduce the load weight.
4. When a thyristor load exists in the same power supply system, install an AC reactor (FR-HAL).