Arc striking/extinguishing mechanism of low-voltage circuit breaker

Abstract

The invention discloses an arc striking / extinguishing mechanism of a low-voltage circuit breaker, which belongs to the technical field of low-voltage apparatus. The mechanism comprises a moving contact, a stationary contact, an arc-extinguishing grid, and a moving-contact arc striking plate, wherein the moving contact is arranged in a shell and electrically connected with a first connecting terminal; the stationary contact is also arranged in the shell and electrically connected with a second connecting terminal; the arc-extinguishing grid is arranged in the shell and used for extinguishing electric arcs produced by disconnecting the moving contact and the stationary contact; and the moving-contact arc striking plate is arranged corresponding to the moving contact, one end of the moving-contact arc striking plate extends to the arc-extinguishing grid, and the other end of the moving-contact arc striking plate is electrically connected with the first connecting terminal. The mechanism provided by the invention is characterized in that a part which is arranged in the shell, between the moving contact and the stationary contact and corresponding to the motion trail of the moving contact is provided with at least an auxiliary arc-extinguishing grid. The mechanism provided by the invention has the advantage of improving the current limiting capacity, breaking capacity and electrical life of the circuit breaker.

Description

technical field [0001] The invention belongs to the technical field of low-voltage electrical appliances, and in particular relates to an arc-starting and arc-extinguishing mechanism of a low-voltage circuit breaker. Background technique [0002] The current-limiting circuit breaker is configured in the low-voltage power grid to limit or disconnect the fault current in the circuit. When a large current such as caused by a short circuit occurs in the circuit, the moving contact arranged opposite to the static contact moves in the direction of opening under the action of the electric repulsion, and an arc will be generated when the moving and static contacts are separated, and the arc is in the self-excited magnetic field Driven by the driving force, it enters the arc extinguishing chamber and extinguishes, so that the short-circuit current is broken. In order to limit the rise of the short-circuit current and improve the breaking capacity, it is a common method to connect th...

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Problems solved by technology

[0005] The applicant has searched, but in published patent literature such as CN1610039A (the arc extinguishing device of the circuit breaker), CN1209777C (the arc extinguishing device of the circuit breaker) and CN1988097A (the arc extinguishing device of the molded case circuit breaker) etc. all do not give The technical enlightenment that can effectively and significantly improve the current limiting capacity and breaking capacity of circuit breakers

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