Circuit breaker with selectivity

Abstract

The invention provides a circuit breaker used in a distribution system, comprising a circuit breaker loop which comprises an overload release, a magnetic release system, a main contact, an auxiliary contact and an operation mechanism, wherein the operation mechanism is used for controlling the closure or cutting off of the main contact and the auxiliary contact under the conditions of the normal working and the overload fault. The circuit breaker also comprises an electronic release accessory loop comprising a selective resistor and an electronic release which are connected in series, wherein the selective resistor and the electronic release are connected with an input circuit part connected to the first electrode of the circuit breaker in series and at least comprising the main contact and the magnetic release system in parallel. Under the condition of a short-circuit fault, the main contact is cut off under the pushing of the magnetic release system so that short-circuit current passes through the auxiliary contact, the selective resistor and the electronic release, the electronic release selectively controls the operation mechanism according to the elimination of the short-circuit fault in the preset delay time, and furthermore, the operation mechanism controls the main contact and the auxiliary contact to carry out corresponding closing or cutting-off operation.

Description

technical field [0001] The present invention relates to a circuit breaker, in particular to a low-voltage miniature circuit breaker capable of providing three-stage fault protection including overload protection, short-circuit delay protection, and short-circuit instantaneous protection, so as to realize miniature protection of lower-level terminals in power distribution networks. Circuit breaker selectivity. Background technique [0002] With the development of electrical automation, miniature DC circuit breakers have become an electrical appliance widely used in low-voltage terminal power distribution systems. It can usually ensure the connection and disconnection under the rated current, voltage and load required by various users. When there is any abnormal fault in the circuit (such as overload or short circuit), it can disconnect the protected circuit by disconnecting the moving contact from the static contact, so that the load can be completely isolated from the power...

AI Technical Summary

Problems solved by technology

This has greatly affected the continuity of power supply of various power distribution systems, especially the continuity of power supply of residential power distribution systems.

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