Small circuit breaker

Abstract

The minitype breaker is composed of the contacting system, arc extinction system, operating apparatus, free dropout apparatus, short circuit protecting system, insulated shell and operating handle, etc. By handler transmission, the operating system drives the movable contact to make the connection and disconnectionof the minitype breaker to control the electric wiring and the electric power energy flow. By detecting the heat and magnetic effect of the electric current, the electric wiring can be protected from overloading and short circuit.

Description

technical field [0001] The invention relates to a miniature circuit breaker with overcurrent protection and short circuit protection. Background technique [0002] Within a unit size range, a small circuit breaker that includes functional units such as a contact system, an arc extinguishing system, an operating mechanism and a free tripping mechanism, an overcurrent protection system, a short circuit protection system, an insulating casing, and an operating handle is used through the handle transmission. The operating mechanism drives the moving contact in the contact system to make the small circuit breaker turn on and off, and realize the control of the power energy flow of the electrical circuit; through the sensing of the thermal and magnetic effects of the current, the electrical circuit is overloaded, Protection against faults such as short circuits. [0003] The structure of multiple unit sizes is composed of a multi-pole miniature circuit breaker by connecting the o...

AI Technical Summary

Problems solved by technology

[0009] In traditional miniature circuit breakers, the role of the soft connection part and other effects caused by the magnetic blowing circuit in series are generally not considered, because the current carried by the soft connection part is different from the current value carried by the conductive part of other rigid structures. are the same, and the influence of its magnetic field effect on the arc blowing effect should not be ignored

[0010] In addition, in the series magnetic blowing circuit of the traditional miniature circuit breaker, when the arc generated between the moving and static contacts due to breaking the short-circuit current enters the arc extinguishing chamber, the transfer of the arc from the moving (static) contact to the arc plate must be completed. Only through the arc path between the arc guide plate and the arc strike angle can it enter the arc extinguishing chamber. In this process, when the arc root of the arc is transferred from the moving contact to the arc guide plate, the electromotive force of the magnetic blowing circuit on the arc There will be a sudden change, because after the arc root is transferred, the current flow circuit has changed, that is, the current at this time no longer passes through the soft connection and the moving contact, and the geometric size of the effective magnetic blow circuit becomes shorter, and the effect of the magnetic blow The force is weakened, and it becomes more difficult for the arc to pass through the arc and enter the arc extinguishing chamber

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