F0789 fault in WEG CFW500 Drive indicates a High Level of the External PID Process Variable. This means the external PID feedback sensor remained above the safe threshold, triggering a system fault.
Cause:
Parameter P1075 is programmed for 2, and the process variable of the external PID controller remained above the value programmed in P1078 for the duration set in P1079.
Remedy:
Verify process line sensors. Check parameter thresholds set in P1075, P1078, and P1079.
