Siemens SINAMICS G120C DP

8.25 Motor protection by calculating the temperature
Overview
The converter calculates the motor temperature based on a thermal motor model. After
commissioning, the converter sets the thermal motor type to match the motor.
The thermal motor model responds far faster to temperature increases than a temperature
sensor.
If the thermal motor model is used together with a temperature sensor, e.g. a Pt1000, then
the converter corrects the model according to the measured temperature.
Function description
Thermal motor model 2 for induction motors
The thermal motor model 2 for induction motors is a thermal 3-mass model, consisting of
stator core, stator winding and rotor. Thermal motor model2 calculates the temperatures -
both in the rotor as well as in the stator winding.
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Figure8-69 Thermal motor model 2 for induction motors
Parameter
Table 8-68 Thermal motor model 2 for induction motors
Number Name Factory setting
r0068[0…1] CO: Absolute actual current value - Arms
p0344[M] Motor weight (for thermal motor model) 0kg
p0604[M] Mot_temp_mod 2/KTY alarm threshold 130°C
p0605[M] Mot_temp_mod 1/2/sensor threshold and temperature value 145°C
p0610[M] Motor overtemperature response 12
p0612[M] Mot_temp_mod activation 0000 0010 0000
0010 bin
p0625[M] Motor ambient temperature during commissioning 20°C
p0627[M] Motor overtemperature, stator winding 80K
r0632[M] Mot_temp_mod stator winding temperature - °C
p0640[D] Current limit 0Arms
Advanced commissioning
8.25Motor protection by calculating the temperature
SINAMICS G120C Converters
342 Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK