If the heatsink temperature is more than the temperature set in L8-02 [Overheat Alarm Level], the drive detects oH [Heatsink Overheat]. To enable this function, set H2-0x [MFDO Function Select] to 20 [Drive Overheat Pre-Alarm (oH)].
Use L8-03 [Overheat Alarm Level] to set the operation when the drive detects oH [Heatsink Overheat].