The devices called thermoresistors are temperature sensors, in which the principle of performance is based on a property, of some components capable of varying the electrical resistance with an expressive variation of temperature. These sensors have a calibrated resistance that can be modified in a linear way in relation to their temperature, guaranteeing a continuous monitoring of the motor heating procedure, by a display of the controller with a high degree of sensitivity and return precision.
This sensor can also act as an alarm, a process that can happen outside the common working temperature, and shutdown, which is usually set to a higher temperature of the insulation class. The resistances of the contacts, cables, as well as other devices, can intervene in the mediation. Several types of configurations can be found, generated in the quest to reduce these results. 5mm pitch gates
The two-wire configuration is often analyzed sufficiently, in environments where the length of the sensor cable to the instrument can not exceed the maximum limit. In the configuration of three wires, the most used by industries, there is a compensation of the electrical resistance by the third wire.