TescoApp, here is one of the KFC-150 manuals (there are several version depending on the associated panel instruments).
https://support.bendixking.com//HWL/...377-0001_1.pdf
The whole set is here (click "discontinued")
https://www.bendixking.com/en/downloads-and-manuals
Page 111, General Emergency Procedures, details the disengagement conditions.
I understand that "Internal Flight Control System failure" covers all the case where the electronic controlling the servos detects that they can't move or need to exercise too high a force.