Siemens alarm A30920: Power unit: Temperature sensor fault
SINAMICS S120 drive warning · SINAMICS S120
What it means
An externally connected motor temperature sensor (KTY84/PTC/PT100) cannot be evaluated properly: wire breakage/not connected (KTY >1630 ohm, PT100 >375 ohm) or resistance too low suggesting short-circuit (PTC <20 ohm etc.). Terminals are X21.1/.2 or X22.1/.2 on booksize units and X41.4/.3 on chassis units. Until fixed, motor thermal protection relies only on the model.
Likely causes
- broken sensor conductor or unplugged sensor lead
- shorted sensor cable/winding-embedded sensor
- wrong sensor type parameterized (p0601)
- corroded terminals on X21/X22/X41
Triage note: If the motor-embedded sensor itself reads short/open, the motor must go out for repair.
Need the part urgently?
Send us alarm A30920 with your machine details — typical RFQ turnaround is 24–48h.