Contact structure for low-current molded case low-voltage circuit breaker

Abstract

The invention discloses a contact structure for a low-current molded case low-voltage circuit breaker. A static conducting rod is positioned at the front-lower part of a movable contact; a static contact is positioned between the static conducting rod and the movable contact; a U-shaped lug boss of which the width is smaller than that of the static conducting rod is bent at the rearmost part of the static conducting rod in an extending manner facing to the opposite direction of current; the orientation of an opening of the U-shaped lug boss is opposite to the direction of the rearmost part current of the static conducting rod; a static contact is fixedly connected onto the U-shaped lug boss; the front end face of the U-shaped lug boss forwards extends at the same width to form a static arc striking sheet which is obliquely bent towards the direction of the movable contact and is abutted together; a distance is reserved between the static arc striking sheet and the static contact; U-shaped magnetism-increasing blocks are formed by eudipleurally upwards extending from the tail of the static conducting rod; four different functions of increasing the resistance of the circuit breaker, enhancing a self-excitation magnetic field in a contact region, absorbing an electric arc generated on the static contact during repelling open of the static contact and forming an electric repelling force between the movable contact and the static contact are achieved by one integral member; and the performance of the circuit breaker is increased.

Description

[0001] Technical field [0002] The invention involves small current shell -shaped circuit breakers, which specifically involves the contact structure of small current shell circuit breakers, and belongs to the field of low -voltage electrical technology. Background technique [0003] Low -voltage circuit breakers are widely used. It is not only used for the protection of non -frequent fusion, division and overloading, short circuit, and under voltage of the main line, branch circuits, and circuit end.Lighting circuit, electric heating circuit, electric motor circuit, capacitor circuit, etc. are used and protected alone.The nature of the load is different, and the rated current and protection characteristics of the circuit breaker are also different.Therefore, according to the nature of the load and the protection function required by the load, the plastic shell fracture that the rated current is smaller is currently used in large quantities. The plastic shell fracture with a sma...

AI Technical Summary

Problems solved by technology

The second structure needs to make three parts, and every two parts need to be connected in a certain way, and this structure can only achieve a simple function of increasing the current limiting resistance, and the number of parts increases, making the static Complicated installation of contacts

In the third structure, the heating element is made into a serpentine structure to increase the resistance. Since the heating element is located in the tripping system of the molded case circuit breaker, in order not to affect the tripping performance of the circuit breaker, the resistance of the general heating element cannot be increased. , so the current limiting effect is not very obvious

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