Scope of this technical record
Siemens MASTERDRIVES motor thermal sensor symptoms involving KTY84 or PTC protection response.
Motor thermal protection must not be bypassed to force operation. Investigate wiring, sensor type and cooling evidence under qualified procedure.
Why this is not only a motor problem
A temperature warning can be true overheating, but it can also be sensor wiring, terminal expansion, parameter response or cooling-path evidence. The page forces a distinction between cold-start sensor faults and load-related heating.
Field evidence
A useful request identifies KTY84 versus PTC, captures when the warning appears, and includes motor fan, bearing, cabinet temperature and terminal wiring evidence.
Field record checklist
- KTY84 or PTC type
- Cold-start versus hot/load timing
- Terminal wiring photos
- Motor fan and cooling condition
- Configured response
Technical basis and reference documents
This is an independent editorial technical reference. Original manufacturer documentation remains controlling for installation, repair and commissioning decisions.
Linked diagnostic workflow.