A high breaking miniature circuit breaker

Abstract

Provided is a high-breaking miniature breaker including a static contact, a movable contact connected with a releasing mechanism and an insulation arc extinguishing mechanism, the insulation arc extinguishing mechanism comprises an insulation shield plate, an armature, a U-shaped magnet yoke, a primary swinging rod and a secondary swinging rod, the insulation shield plate is arranged under the movable contact of the circuit breaker and corresponds to the gap between the static contact and the movable contact, the primary swinging rod and the secondary swinging rod are parallel to each other and form a four-linkage mechanism with the movable contact and the insulation shield plate, the armature is arranged over the movable contact and fixed on the rotating handle of the upper end of the primary swinging rod, the U-shaped magnet yoke sleeves on the movable contact from the bottom and corresponds to the armature, and a torsion spring is arranged between the primary swinging rod and the movable contact. The insulation shield plate can be quickly inserted into the gap between the movable contact and the static contact when the circuit breaker breaks the short-circuit current, so that the arc can be extinguished, in this way, the arc energy amplification time is shortened, the short flashover or no flashover of the circuit breaker is realized, and the short-circuit current breaking capability of the circuit breaker is greatly improved.

Description

technical field [0001] The invention relates to a small circuit breaker with strong short-circuit current breaking capacity, belonging to the technical field of emergency protection devices. Background technique [0002] Miniature circuit breakers (MCBs) are important electrical components in industrial and civil low-voltage power distribution equipment. They are mostly used at the end of low-voltage power distribution systems to protect distribution lines from overload and short-circuit faults. Among them, short-circuit fault protection is its most important function. Since the short-circuit current of the line is very large during a short-circuit fault, when the circuit breaker breaks the short-circuit current, a plasma arc with high energy will be generated between the moving and static contacts. Only the arc extinguishing components can quickly extinguish the arc, and the circuit breaker can complete the task of breaking the short-circuit current. [0003] At present, M...

AI Technical Summary

Problems solved by technology

The arc extinguishing effect of this method is affected by factors such as the material of the arc extinguishing chamber, the breaking speed of the contacts, the distance between the contacts, the material of the contacts, etc. Relatively poor, generally no more than AC 230V, 6kA, and the DC short-circuit current is more difficult to break because there is no zero-crossing process

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