Cause : Chip overtemperature comes when he chip temperature of the semiconductor has exceeded the permissible limit value.

- the permissible load duty cycle was not maintained.
- insufficient cooling, fan failure.
- overload.
- ambient temperature too high.
- pulse frequency too high.

1. adapt the load duty cycle.
2. check whether the fan is running.
3. check the fan elements.
4. check whether the ambient temperature is in the permissible range.
5. check the motor load.
6. reduce the pulse frequency if this is higher than the rated pulse frequency.