PURPOSE: To drive a high output circuit breaker by means of a low-cost low output driving mechanism by arranging a trigger circuit breaker driving mechanism, which is connected to a device having a disengagement first spring and an engagement second spring, and a recocking motor recocking both of the springs rotating a main shaft by 180° in a releasing time.

CONSTITUTION: When an opening command for a circuit breaker is generated from a device protecting a grid/line to which a circuit breaker is inserted, a trigger driving mechanism turns a shaft 2 in the direction f1. Then, a crank 22 drives a connection rod 24 and turns further while pulling a crank 29 releasing a stopper 20, and a spring 6 moves an arm 5, which is turns in the F1 direction by 180° so as to open the circuit breaker by means of a shaft 4. When the trigger driving mechanism receives a closing command, the trigger shaft 2 is rotated in the f2 direction. Then, a cam 17 presses a wheel stopper 16 and is driven by a spring 12 after it passes a fixed center at the top, and an arm 11 turns the shaft 4 downward by 180°, so that the circuit breaker is engaged again. At the same time, the shaft 4 rotates the arm 5 so as to cock the spring 6 again.