Cause : Temperature in the line filter permanently too high comes when the temperature monitoring responded, the temperature in the line filter was permanently exceeded.

- check whether the line filter type set in p0220[0] matches the line filter that is actually connected. Ensure that the line filter specified for the infeed being used is connected or correct the setting of the line filter type in p0220[0].
- temperature monitoring is mandatory for AIM line filters (refer to p0220). Ensure that the temperature switch in the line filter is correctly and reliably connected to input X21 of the infeed.
- reduce the ambient temperature of the line filter.
- reduce the load on the infeed and the line filter.
- check the magnitude of the line supply voltage.