Investigation sequence
Identify sensor type
Confirm KTY84 measurement or PTC thermistor protection and the configured warning/fault behaviour.
Classify timing
Cold-start faults suggest wiring or sensor boundary; load/ambient-related faults may be real heating.
Inspect wiring route
Check motor terminal box, shielded cable, terminal expansion and loose/contaminated connections.
Inspect cooling evidence
Record motor fan, bearing state, airflow obstruction and cabinet ambient when real overheating is possible.
Preserve protection
Correct wiring or cooling faults without disabling the protective function.
Stop conditions
- Sensor type unknown
- User asks to bypass thermal input
- Motor is visibly overheating
- Vertical or critical load cannot be safely tested
Linked records
The fault boundary includes the motor thermal sensor, KTY84/PTC wiring, terminal expansion path and the parameterized response to warning or fault shutdown.
Routes KTY84 and PTC motor-temperature evidence through terminal input, expansion-board context and configured warning/fault response.