A new concept of fault diagnosis is based on measuring the contact resistances of the individual contacts of the internal circuits of the high voltage circuit breaker by using the IOT based circuit. In this equipment, we measure the resistance of the NO and the NC contact by using the voltage and current sensor, Arduino kit. In this ardinuo kit we are programmed such that the sensor senses the value of the voltage and current it goes to the Arduino kit and pre-insert value of the resistance formula in a programmed and according to the value resistance we will get the condition healthy or unhealthy and also we get the resistance values of the contact for the preventive maintenance.