2.3.3. Thermistor Input
The thermistor input is used to detect a motor over temperature condition by using a positive
temperature coefficient sensor. As the temperature of the sensor increases, so does the resistance.
Under normal operating conditions, the resistance of the thermistor is low which will result in a low input
signal. As the increasing temperature causes the thermistor’s resistance to increase, the sensor will
trigger an over temperature fault.
The thermistor is connected between Pin 2 and Signal Common. The nominal trip value of the sensor is
1.385 kΩ. The circuit includes a 12 kΩ internal pull-up resistor which corresponds to a trip voltage of
+0.52 V.
Table 2-14:
Thermistor Input Pin on the Feedback Connector
Pin #
Description
In/Out/Bi
2
Motor Over Temperature Thermistor
Input
Figure 2-18:
Thermistor Input Schematic (Feedback Connector)
2.3.3. Thermistor Input
XR3 Hardware Manual
48
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