PTC Thermistors - Electric Motor Parts & Accessories Australia​

Ptc Thermistors  – Electric Motor Parts & Accessories Australia​

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Thermik’s design their PTC Thermistor so that a technician can install  them in the winding of an electric motor and of course transformers.

Protecting the  motor windings against a continuous overload condition,also high ambient temperature and a locked rotor condition. It is quite common to install three together in series so as to protect each phase of a three phase motor.


Thermik PTC Thermistors correspond to DIN 4408, DIN 44082 and IEC 34-11-2. On the whole many consider the company a specialist when it comes to winding temperature protection and is definitely one of the best in the world in its field.

Each PTC Thermistor has a transition temperature and its resistance remains quite constant and low. When the semi conductor reaches transition temperature, the sensor’s resistance increases abruptly. This can switch off the load circuit via a relay. Our sensors have a very high temperature sensitivity. Each temperature sensor needs  to pass a test several times during and after manufacture.


PTC thermistors  are also commonly referred to as motor protection sensors, PTC thermistors, PTC sensors, PTCs and temperature sensors.   Another key point is that Thermistors are internationally colour coded as in the diagram below. Temperatures can range from 80 degree celsius to 180 degree celsius. Further as on the diagram Triplex and duplex versions are available on special requests. The bridging cables keeping the semi-conductors in series are usually yellow in colour. We offer different semi-conductor protection sleeve materials like Kynar, Fep and  Mylar depending on customer requirements.

To choose a PTC thermistor temperature for a rewind, consult the electric motor name plate or speak to a technical adviser at 

Ptc Thermistors  – Electric Motor Parts & Accessories Australia​