Falling-prevention single-break contact operation mechanism

Abstract

The invention discloses a falling-prevention single-break contact operation mechanism which comprises a movable contact, a fixed pin, an installation frame, a movable pin, a sliding block and a spring. The fixed pin is arranged in the middle of the movable contact, the movable contact rotates around the fixed pin, a containing cavity is formed in the installation frame, the spring is arranged at the bottom of the containing cavity, and the sliding block is arranged in the containing cavity and above the spring. One side of the sliding block extends upwards to form a sliding block protrusion, a sliding groove is formed in the installation frame, the movable pin can move vertically along the sliding groove to be arranged in the sliding groove, one end of the movable contact stretches in the containing cavity and extends downwards to form a movable contact protrusion, a curved-surface groove is formed in the movable contact, and the movable pin abuts against the part between the movable contact protrusion and the sliding block protrusion under the action of the elastic force of the spring. The falling-prevention single-break contact operation mechanism can effectively prevent the contacts from falling, prolong the electrical service life of a breaker and improve the breaking capability of the breaker.

Description

technical field [0001] The invention relates to a circuit breaker contact operating mechanism, in particular to an anti-drop single break point contact operating mechanism. Background technique [0002] Molded case circuit breakers are branch-level power distribution appliances of power distribution systems. With the continuous increase of grid capacity and the needs of centralized power distribution, the system requires higher and higher breaking capacity, so the current-limiting contact structure has been used in plastic case Widely used in circuit breakers. However, the repelling force of the contacts of the current-limiting double-break point structure depends on the current passing through the contacts, that is, when the current value increases to a certain value, the dynamic and static contacts will be separated by the loop electromotive force and the node electromotive force. At this time, the resistance between the contacts increases rapidly and the periodic change ...

AI Technical Summary

Problems solved by technology

However, the repelling force of the contacts of the current-limiting double-break point structure depends on the current passing through the contacts, that is, when the current value increases to a certain value, the dynamic and static contacts will be separated by the loop electromotive force and the node electromotive force. At this time, the resistance between the contacts increases rapidly and the periodic change of the AC current will cause the current flowing through the contacts before the circuit breaker breaks to attenuate to the point where the electromotive force is less than the repulsion between the moving and static contacts. In the case of opening force, at this time, the previously repelled contacts will move from the repelled position to the closed position with the reduction of the electric force, which will cause the so-called contact drop phenomenon, and the contact drop will cause contact between the contacts. The reduction of the arc voltage causes the arc to reignite so that the fault current cannot be interrupted

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