Contact system of circuit breaker

Abstract

The invention discloses a contact system of a low-voltage circuit breaker. The low-voltage circuit breaker comprises an upper bottom board, a lower bottom board, a moving contact, a fixed contact and an operating mechanism, wherein the lower bottom board and the upper bottom board are fixed on the circuit breaker body, a moving conducting bar is fixed on the lower bottom board, and a fitting piece is fixed on the moving conducting bar; a rotating shaft and a plastic case frame are fixed on the moving contact body, the rotating shaft is sheathed in a hole of the fitting piece, the moving contact body can rotate around the rotating shaft, and a fairing is fixed on the front end of the moving contact and moves along with the moving contact; both ends of a reflecting board stretch into guide slots of the upper bottom board and the lower bottom board and move under the limiting of the upper guide slot and the lower guide slot and the driving of the moving contact; and the fixed contact comprises a fixed conducting bar, a fixed board and an arc striking sheet. By applying the contact system, the gap between the moving contact and the fixed contact when the circuit breaker is disconnected is filled, the strength of air released by the fairing and the reflecting board is enhanced, the pressure of air near the moving contact and the fixed contact is increased, the air blowing action and the arc extinguishing action on electric arcs are enhanced, and the interruption performance of the circuit breaker can be increased.

Description

technical field [0001] The invention belongs to the technical field of low-voltage electrical appliances, and relates to a contact system of a circuit breaker. Background technique [0002] With the rapid development of the national economy, the capacity of the power grid will continue to rise, so improving the breaking capacity of circuit breakers is an eternal goal. When the existing circuit breaker breaks the short-circuit current, the breaking capacity of the circuit breaker is often limited due to the severe contact ablation of the moving contact and the inability of the arc to enter the grid of the arc extinguishing chamber in time. As we all know, when the short-circuit current is broken, when the moving and static contacts of the circuit breaker are separated, an arc will be generated between the moving and static contacts. The longer the arc stays on the moving and static contacts, the more The more serious the ablation. Therefore, it is the goal pursued by the in...

AI Technical Summary

Problems solved by technology

Therefore, under the existing structure, the gap 7 between the moving and static contacts is unavoidable when the circuit breaker is opened, which affects the gas pressure near the contacts and the pushing effect of the gas thrust on the arc, affecting the opening of the circuit breaker. break performance

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