Electric circuit breaker

Abstract

To provide a circuit breaker which can bring the whole arc to an arc-extinguishing device quickly and has a high breaking performance even when breaking a high current such as a short circuit current. The circuit breaker comprises a fixed contact piece 4 having a fixed contact point 3; a movable contact piece 1 having a movable contact point 2 making contact with / coming off the fixed contact point; an arc-extinguishing device 20 which injects an arc onto a plurality of arc-extinguishing plates 11, partitions the arc, and extinguishes the arc, where the arc occurs between a pair of contact points composed of the fixed contact point and the movable contact point, when the movable contact point comes off; and a pair of fixed contact side steering members and movable contact side steering members 10, 101, 13, which steer the arc from the pair of the contact points to the arc-extinguishing device. The surface direction component of arc-extinguishing plate for the arc-extinguish plates 11a placed at the latter arrival side of the arc to the arc-extinguishing device at a distance between the fixed contact point and an arc injection position on the end surface side of the pair of the contact points is larger than the similar surface direction component for the other arc-extinguish plates 11b. The surface direction component of arc-extinguishing plate for the arc-extinguish plates 11a placed at the latter arrival side of the arc to the arc-extinguishing device at a distance between the fixed contact point and an arc injection position on the end surface side of the pair of the contact points is larger than the surface direction component of arc-extinguishing plate for the other arc-extinguish plates 11b, at a distance between the fixed contact point and an arc injection position on the end surface side of the pair of the contact points.(C)2004,JPO&NCIPI.

Description

technical field [0001] The present invention relates to a circuit breaker that interrupts a circuit when an overcurrent such as an overload current or a short-circuit current occurs. Background technique [0002] In the conventional circuit breaker, the main circuit formed by inserting the contact part between the power supply side terminal and the load side terminal, if an excessive current flows through the main circuit when the contact part is closed, the contact part is forcibly opened. In the circuit breaker, a pair of arc traveling plates are provided that are electrically connected to the contacts constituting the contact part, extend in the direction of the electromagnetic force acting on the arc through the interaction with the magnetic field around the contact part, and are arranged opposite to each other. , form the side walls of the space that accommodates the two arc traveling plates so that the distance between them increases in the direction of the electromagn...

AI Technical Summary

Problems solved by technology

[0004] In such a circuit breaker, especially when the short-circuit current is interrupted, there is a structure in which the arc point generated between the contact pair cannot continuously travel to the circuit breaker (a structure in which the arc travel route is discontinuous and requires commutation), or in the Between the contact pair and the arc extinguishing device, the section along the arc traveling direction of the arc traveling surface is a convex structure. The movement of the arc end on one side is relatively slower than that on the other side, and sometimes stagnates in the middle. Therefore, there is a disadvantage that the arc cannot be quickly introduced into the arc suppression device as a whole

[0005] In this way, there is a problem that high-speed interruption performance cannot be obtained because the entire arc cannot be quickly introduced into the arc extinguishing device.

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