Connecting Temperature Sensors - Siemens SIMOTICS T-1FW3 Configuration Manual

Electrical connection
8.3 System integration
8.3.3.3

Connecting temperature sensors

Motor versions with 3x PTC
For special applications (e.g. when a load is applied with the motor stationary or for
extremely low speeds), the temperature of all of the three motor phases must be additionally
monitored using a 3 x PTC thermistor triplet (option A11).
The PTC thermistor triplet must be evaluated using an external trip unit (this is not included
in the scope of delivery). This means that the sensor cable is monitored for wire breakage
and short-circuit by this unit. The motor must be switched into a no-torque condition when
the response temperature is exceeded.
Note
The PTC thermistors do not have a linear characteristic and are, therefore, not suitable to
determine the instantaneous temperature. PTC characteristic to DIN VDE 0660 Part 303,
DIN 44081, DIN 44082.
308
1FW3 complete torque motors
Configuration Manual, 08/2020, A5E46027705B AA