Arc extinguishing equipment of moulded case circuit breaker

Abstract

The invention discloses an arc extinguishing equipment of a moulded case circuit breaker. The front wall of an arc extinguish chamber is provided with a gas outlet, and the rear wall is provided with a rear opening; the front end of a moving contact stretches into the cavity of the arc extinguish chamber from the exterior through the rear opening; the front end of the moving contact is connected with a moving contact plastic part; the front part of the moving contact plastic part is provided with a groove wrapping the front end of the moving contact; two side walls of the groove are provided with round holes; the moving contact is provided with circular platforms matched with the round holes; the rear end of the groove is provided with a channel; the moving contact is provided with a bard-shaped boss clamped into the channel; the front part of the moving contact plastic part extends towards the rear inferior and is bent with a rear boss; in the repelling process of the moving contact, the rear boss moves to the position which can block the rear opening along with the moving contact to block the rear opening of the arc extinguish chamber to the greatest extent so as to enhance the pressure in the arc extinguish chamber and enhance the air-blowing function in the arc extinguish chamber, and the arc extinguishing equipment can effectively improve the disjunction of the moulded case circuit breaker and enhance the current-limiting performance.

Description

technical field [0001] The invention relates to a molded case circuit breaker, in particular to an arc extinguishing device of the molded case circuit breaker, and belongs to the technical field of low-voltage electrics. Background technique [0002] The arc extinguishing chambers of existing molded case circuit breakers are generally composed of arc extinguishing grids and gas-generating materials. When the circuit breaker is disconnected, the moving and static contacts are repelled and an arc is generated. Since the contact movement route of the moving contact is in the cavity of the arc extinguishing grid of the arc extinguishing device, the arc enters the arc extinguishing grid under the action of electromotive force, and cuts the arc into a series of short arcs in series, making the arc thinner And quickly increase the arc voltage, so as to achieve the role of arc extinguishing. At the same time, the gas-generating material will generate gas when the circuit breaker i...

AI Technical Summary

Problems solved by technology

However, since there is an opening at the rear of the arc extinguishing chamber for the moving contact to enter the arc extinguishing chamber, during the process of gas blowing and extinguishing the arc in the arc extinguishing chamber, a part of the gas moves towards the rear opening, causing the entire arc extinguishing The drop of air blowing pressure in the chamber weakens the effect of air blowing, which is not conducive to improving the arc extinguishing performance of the circuit breaker

Moreover, when the circuit breaker is disconnected, due to insufficient air blowing pressure, the metal particles produced by the arc or arc burnt contacts will adhere to the grids, causing a short circuit between the grids and reducing the breaking performance of the circuit breaker.

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