Power device for continuously detecting entry and exit positions

A power device for continuously detecting each of extended and retracted positions of a circuit breaker body, the device comprising:

• a cradle having a cradle terminal;
• a circuit breaker body mechanically and electrically connected to or disconnected from the cradle terminal;
• and
• a girder and a truck as transporting means for moving the circuit breaker body to a contact or disconnection position with or from the cradle terminal,
• wherein the power device further comprises:
• a position detected area portion formed on at least one of both opposing side faces of the circuit breaker body;
• and
• a sensor module fixed to at least one of both opposing inner side faces of the cradle, wherein the sensor module includes at least one sensor facing the position detected area portion so to detect a displaced position of the position detected area portion and thus to detect a position of the circuit breaker body, based on the detected displaced position.