The principles of several displacement sensors used for testing the mechanical properties of medium voltage circuit breaker are described. For the compact features of mechanical actuator structure of medium voltage circuit breaker

study and contrast between the working principle

signal detection circuit and the tests are conducted to select two kinds of breaker displacement sensor using for the medium voltage circuit breaker. Practice has proved that: both sensors are desirable to measure the trip of the circuit breaker; the trip characteristics can be truly reflected

and the original performance parameters and reliability aren’t affected; in addition

they can work stably in long-term in harsh environments with high voltage

high current

high shock and vibration.