Thermal Motor Protection - Siemens SINAMICS S120 Commissioning Manual

Commissioning
2.13 Commissioning linear motors (servo)
2.13.4

Thermal motor protection

Temperature monitoring circuits Temp-F and Temp-S
The motors are supplied with two temperature monitoring circuits: Temp - F and Temp - S.
Temp-F is to monitor and evaluate the temperature characteristic in the motor being used.
Temp-S is used to activate the motor protection in the event of overheating in the motor
windings.
Both temperature monitoring circuits are independent of each other. The evaluation is
realized via the Control Unit. The temperature sensors are connected to the drive system or
to the Motor Module using Sensor Modules from the SME12x series.
Temp-F (KTY 84 Sensor)
The temperature monitoring circuit Temp-F consists of a KTY 84 temperature sensor located
at the coils. Under certain circumstances – for example when the individual phases have
different current levels – this can mean that the maximum temperature of the three phase
windings is not Detective. Therefore, it is not permissible for motor protection to solely
evaluate the Temp-F temperature monitoring circuit. Temp-F is used to monitor the
temperature - and if necessary to output an alarm indicating that the drive is being shutdown
because the Temp-S temperature monitoring circuit has responded.
Temp-S (PTC element)
The temperature shutdown circuit comprises PTC thermistor temperature sensors (PTC
elements). There is a PTC thermistor temperature sensor for monitoring the motor winding in
each of the three phase-windings (U, V and W). This ensures overload protection, even if the
current in the individual phases of a primary section is not the same - or if several primary
sections have different load levels. The PTC elements are connected in series.
The circuit and connection system for Temp-F and Temp-S are described in detail in the
Configuration Manual; linear motors 1FN3 or 1FN6.
The SME12x (Sensor Module External) is a device with connectors enabling the connection
of various sensors of a direct drive (WMS, Hall sensors, temperature sensors). The output of
the SME12x is connected to SINAMICS drive systems via DRIVE-CLiQ. The requirements
regarding protective separation in accordance with EN 61800-5-1 are fulfilled by the
electrical isolation between the voltage circuits for power and sensors. The SME12x
therefore fulfills the following functions:
● All signal cables can be connected close to the motor.
● Temperature sensors can be fully evaluated:
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– Thermal motor protection through evaluation of Temp-S
– Display of the temperature curve via evaluation of Temp-F
Commissioning Manual, (IH1), 01/2012, 6SL3097-4AF00-0BP2
Commissioning Manual