Cause : Motor overload trip (electronic thermal relay function) comes when the electronic thermal relay function in the inverter detects motor overheat due to overload or reduced cooling capability during constant-speed operation and pre-alarm (TH display) is output when the integrated value reaches 85% of the Pr. 9 Electronic thermal O/L relay setting and the protection circuit is activated to stop the inverter output when the integrated value reaches the specified value.

When running a special motor such as a multi-pole motor or multiple motors, provide a thermal relay on the inverter output side since such motor(s) cannot be protected by the electronic thermal relay function.

1. Check the motor for use under overload.
2. Check that the setting of Pr. 71 Applied motor for motor selection is correct.
3. Check that stall prevention operation setting is correct.
4. Reduce the load weight.