Low-voltage breaker

Abstract

The invention discloses a low-voltage breaker, belonging to the technical field of low-voltage breakers. The low-voltage breaker comprises a shell, at least one circuit breaking and arc extinguishing device, an operation mechanism capable of cutting off or closing and a tripping device. The circuit breaking and arc extinguishing device comprises an arc extinguishing chamber component and a contact component. The arc extinguishing chamber component comprises a plurality of arc extinguishing grid plates and an arc isolating cover. Each arc extinguishing grid plate is provided with a basal part and a pair of extending legs extending from one end of the basal part, the arc isolating cover is provided with a pair of first wall bodies, a pair of second wall bodies and a pair of third wall bodies, a plurality of arc extinguishing grid plates form a contact cavity, the contact component corresponds to the contact cavity, and the second wall bodies correspond to the interior of the contact cavity. The invention is characterized in that the arc isolating cover also comprises a pair of inner walls, each inner walls is jointed with one end of each second wall body near the basal part of each arc extinguishing grid plate, the other end of each second wall body is jointed with each third wall body, and each inner walls is provided with grids. The invention prevents ablation of electric arcs to the extending legs, can protect the extending legs, prolongs the service life of the arc extinguishing chamber component, achieves fast arc extinguishing effect, and enhances the breaking capacity.

Description

technical field [0001] The invention belongs to the technical field of low-voltage circuit breakers, and in particular relates to a low-voltage circuit breaker. Background technique [0002] A low-voltage circuit breaker is an electrical device that protects circuits and loads by cutting off short-circuit current or overload current. The low-voltage circuit breaker includes a housing, at least one contact assembly and at least one arc extinguishing chamber assembly that matches the contact assembly. The circuit breaker arc extinguishing device, the operating mechanism that can be opened and closed, and the tripping device used to drive the operating mechanism to act, wherein the rapid arc extinguishing capability of the circuit breaker arc extinguishing device is not only the basic function of the circuit breaker, but also a must Require. The circuit breaking and arc extinguishing device includes the arc extinguishing chamber assembly and the contact assembly. The arc extin...

AI Technical Summary

Problems solved by technology

However, the applicant thinks that the above-mentioned structure still has shortcomings, which can be achieved by image 3 Interpretation of the arc path shown by the schematic arc extinguishing chamber assembly 11, due to the structure of the arc shield 112 and the cooperation between the arc shield 112 and the extension leg 1111, there is a dead angle 21 in the area near the end of the extension leg 1111 , when the arc 2 is generated, the arc 2 stays in the dead angle 21 of the air flow and ablates the extension leg 1111, which damages the service life of the arc extinguishing grid 111; Therefore, the temperature of this place (including the arc gas here) is relatively low, and the free metal particles in the arc 2 are very likely to stay at the ends of the extension legs 1111 and condense (deposit) into solid metal particles, which will lead to extinction in severe cases. The short circuit between the arc grids 111 reduces the breaking capacity of the circuit breaker

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