Mounting and options
3.3 Thermal motor protection
S-1FK7 DYA G2 synchronous motors with planetary gearbox
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Operating Instructions, 05/2018, A5E44881183B AA
3.3
Thermal motor protection
Two Pt1000 temperature sensors in the stator winding (one of which is reserve) monitor the
motor temperature.
Table 3- 1
Features and technical data
Type
Pt1000
Resistance when cold (20 °C)
Approx. 1090
Ω
Resistance when hot (100 °C)
Approx. 1390
Ω
Connection
Via signal cable
Response temperature
Prewarning < 150 °C
Alarm/trip at max. 170 °C ±5 °C
The resistance change is proportional to the winding temperature change. The temperature
characteristic is taken into account in the closed-loop control.
The following diagram shows the resistance characteristic as a function of the temperature
for Pt1000 temperature sensors.
Figure 3-1
Pt1000 characteristic
The winding temperature is evaluated in the converter. When a fault occurs, an appropriate
message is output at the converter. When the motor temperature increases, a message
"Alarm motor overtemperature" is output. The message can be evaluated externally.
If this message is ignored, the converter shuts down with the appropriate fault message after
a preset time period or when the motor limiting temperature or the shutdown temperature is
exceeded.
The integrated temperature sensor protects the synchronous motors only to a certain extent
against overloads:
