Siemens 611 Thermal motor protection, Description of the temperature sensors, Temperature sensor

Motor components of the built-in motor and options 3.2 Thermal motor protection

Table 3- 1 Cooling method

Size	Cooling jacket	Integrated cooling
1FW609	X
1FW613	X
1FW615	X
1FW616		X
1FW619		X
1FW623		X
1FW629		X

3.2Thermal motor protection

3.2.1Description of the temperature sensors

Temperature sensor

1FW6 stators are equipped with the two temperature monitoring circuits described below (Temp-S and Temp-F) to protect the stator against excessive thermal stressing and to monitor the temperature during commissioning and operation:

Temp–S

Two temperature shutdown circuits consisting of PTC thermistor detectors (PTC elements) are provided for monitoring the motor winding:

●1 x PTC 130 °C element per phase winding (U, V, and W), i.e. switching threshold at 130 °C and

●1 x PTC 150 °C element per phase winding (U, V, and W), i.e. switching threshold at 150 °C.

The PTC elements of the two temperature shutdown circuits are each connected in series with a triplet.

The characteristics of the PTC elements comply with DIN VDE 0660 Part 303, DIN 44081, and DIN 44082 (also refer to the subsequent table).

The cable connection is also monitored with PTCs 80 °C on the housing. A PTC 80 °C is connected to the PTC 130 °C triplet and a PTC 80 °C is connected to the PTC 150 °C triplet in series.

Function:

Each PTC element has a "quasi-switching" characteristic; i.e. in the vicinity of the rated response temperature ϑNAT (switching threshold) the resistance changes suddenly (step function). As a result of the low thermal capacity and the good thermal contact between the PTC element and the motor winding, the sensors - and therefore also the system - quickly respond to inadmissibly high stator temperatures.

44	1FW6 Built-in torque motors
	Configuration Manual, 05/2009, 6SN1197-0AD00-0BP7