Tripping device for circuit breaker

Abstract

The invention discloses a tripping device for a circuit breaker. The tripping device comprises a U-shaped iron core and an armature, wherein the armature is arranged at the opening end of the U-shaped iron core; a working air gap is formed between the armature and the opening end of the U-shaped iron core; the U-shaped iron core and the armature form a first magnetic circuit; a main current loop of the circuit breaker passes through the first magnetic circuit to provide excitation; and a signal measuring coil is wound on the U-shaped iron core. Further, a branch iron core is connected with the part, close to the opening end, of the U-shaped iron core; the branch iron core and a part of the U-shaped iron core form a closed magnetic circuit; moreover, in the closed magnetic circuit, the branch iron core achieves magnetic saturation earlier than the U-shaped iron core; and when short-circuit current appears in the main current loop, the magnetic force between the armature and the U-shaped iron core drives the armature to move relative to the U-shaped iron core. Compared with the prior art, the tripping device can effectively monitor fault current such as overload current, short-circuit current and the like, and has a compact structure.

Description

technical field [0001] The invention relates to a release, in particular to a release for a circuit breaker. Background technique [0002] A typical molded case circuit breaker generally realizes thermal protection and short circuit protection of the circuit breaker by setting a bimetal element and an electromagnetic release. In particular, in order to meet the operating characteristics during thermal protection, the bimetal or the heater will generate a large amount of power loss in the form of heat. [0003] In order to overcome the above-mentioned problems of circuit breakers, electronic molded case circuit breakers equipped with current transformers were born. This type of circuit breaker greatly reduces the temperature rise of the circuit breaker. To judge the short-circuit current, so the opening time of the circuit breaker is often longer, especially when breaking a large short-circuit current, this longer opening time is unfavorable, so it is often installed in the ...

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Problems solved by technology

[0003] In order to overcome the above-mentioned problems of circuit breakers, electronic molded case circuit breakers equipped with current transformers were born. This type of circuit breaker greatly reduces the temperature rise of the circuit breaker. To judge the short-circuit current, so the opening time of the circuit breaker is often longer, especially when breaking a large short-circuit current, this longer opening time is unfavorable, so it is often installed in the electronic molded case circuit breaker The backup electromagnetic release is used to shorten the breaking time when a large short-circuit current occurs, but this brings new problems: since the backup electromagnetic release and the current transformer are set separately, it occupies a large volume and the structure is not compact. It is not conducive to the miniaturization development of circuit breakers

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