Cause : IGBT over-heating warning comes when the drive's internal temperature has exceeded the safe operating limit. This warning occurs when IGBT temperature is higher than Pr.06-15 setting value.

The error code oH1 on a Delta MS300 drive indicates an "Overheat (Heatsink)" fault. This means the heatsink, which is responsible for dissipating heat from the drive, has reached an excessively high temperature.

1. Check the ambient temperature.
2. Regularly inspect the ventilation hole of the control cabinet.
3. Change the installed place if there are heating objects, such as brake resistors, in the surroundings
4. Decrease loading.
5. Decrease the carrier wave.
6. Replace with a drive with larger capacity.
7. install/ add cooling fan or air conditioner to lower the temperature inside the cabinet