What it means
Alarm A35920 is raised by a Terminal Module (TM) when an error occurs while the module evaluates the temperature sensor connected to its channel 0. The alarm value tells which of the two monitored conditions occurred: the sensor circuit is interrupted (wire breakage or the sensor is not connected), or the measured resistance has dropped below the threshold for the connected sensor type. Depending on how the drive is configured, the same condition can also be reported as a fault or as a message without a reaction instead of the alarm.
Why it appears
- An error occurred when the Terminal Module evaluated the temperature sensor on channel 0.
- Value 1: wire breakage or the sensor is not connected — the measured resistance is above the threshold the drive applies for the connected sensor type.
- Value 2: the measured resistance is below the threshold the drive applies for the connected sensor type.
What to check
- Read the alarm value in r2124 (decimal) to see whether the drive detected wire breakage or a not-connected sensor (1) or a too-low resistance (2).
- Make sure that the temperature sensor is connected correctly to the Terminal Module.
- Replace the sensor.
Reading the message value
- The drive enters the detected condition into the alarm value r2124; interpret the value as a decimal number.
- 1 — wire breakage or sensor not connected: KTY84: R > 1630 Ohm (TM150: R > 2170 Ohm), PT100: R > 194 Ohm, PT1000: R > 1720 Ohm (TM150: R > 1944 Ohm)
- 2 — measured resistance too low: PTC thermistor: R < 20 Ohm, KTY84: R < 50 Ohm (TM150: R < 180 Ohm), PT100: R < 60 Ohm, PT1000: R < 603 Ohm
Parameters the manual names
- r2124 — alarm value of this alarm, interpreted decimal: 1 = wire breakage or sensor not connected, 2 = measured resistance too low. Read it here to determine which condition the Terminal Module detected on channel 0.
Acknowledging and restarting
The alarm requires no acknowledgement; it clears once the drive no longer detects the sensor error. If the drive reports the same condition as a fault, that fault is acknowledged immediately by switching the power on (POWER ON).
What differs between the drive families
Straight from the manuals' own fields — A35920 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | — | — | External measured value / signal state outside the permissible range (16) | Terminal Module (TM) | SINAMICS S120, S150 List Manual · p. 3243 |
| G130, G150 | NONE | NONE | External measured value / signal state outside the permissible range (16) | Terminal Module (TM) | SINAMICS G130, G150 List Manual · p. 1906 |
The drives this code lives on
A35920 is described for G130, G150, S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does alarm A35920 in SINAMICS mean?
A Terminal Module (TM) detected an error while evaluating the temperature sensor on channel 0 — either wire breakage or a sensor that is not connected, or a measured resistance that is too low.
How do I clear A35920?
Make sure the temperature sensor is connected correctly to the Terminal Module and replace the sensor. The alarm itself needs no acknowledgement; if the drive reports the condition as a fault, it is acknowledged by switching the power on (POWER ON).
Which sensor resistances trigger A35920?
Wire breakage is detected when the resistance exceeds the sensor-type threshold: KTY84 above 1630 Ohm (TM150: 2170 Ohm), PT100 above 194 Ohm, PT1000 above 1720 Ohm (TM150: 1944 Ohm). A too-low resistance is detected for a PTC thermistor below 20 Ohm, KTY84 below 50 Ohm (TM150: 180 Ohm), PT100 below 60 Ohm or PT1000 below 603 Ohm.
Where can I see why A35920 was raised?
Read the alarm value in r2124 as a decimal number: 1 means wire breakage or the sensor is not connected, 2 means the measured resistance is too low.
Codes next to this one
Source
Written from Siemens' own List Manuals and operating instructions; every number, designation and parameter on this page is checked against them before publication.
All SINAMICS codes: fault and alarm codes · the A35xxx group · SINAMICS manuals · Siemens manuals