Question

Do I have to use thermistor protection with my motor/drive? Why does the thermistor resistance change from sensor to sensor?

Answer

Here in the US, there are no stipulations requiring the use of thermistors (or other temperature sensing devices). People use them as a common sense method of protecting an investment. NEC article 430-32 lists it as one of 4 ways to be compliant. Other mfg's offer it in many forms; thermistor, pyrometer, thermocouple, and RTD. All of these can be used as a temperature measuring/sensing device.

The reason that the resistance differs from sensor to sensor is because of the different type of material or different dimensions of the same material being used.

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FAQ Subcategory: None

This item was last updated on 2004-02-24
Document ID: 870

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