Multipolar DC molded case circuit breaker

Abstract

The invention discloses a multipolar DC molded case circuit breaker, which solves the problems of arc and relatively lower operating voltage caused by difficulties in breaking DC failures in the prior art. The multipolar DC molded case circuit breaker comprises a case, and a contact system, an overload protection tripper, a short-circuit protection tripper, a wiring board and arc quenching chambers of each pole which are assembled in the case. Technical key points are that: the case is made from a dough molding compound; a permanent magnet magnetic quenching mechanism is arranged at a single breakpoint between a moving contact and a fixed contact, and comprises a permanent magnet which is assembled at the bottom of a substrate; the upper ends of two concentrating flux plates are arranged on the two sides, corresponding to an arc generation position, of a contact room of the arc quenching chamber respectively, and the lower ends of the concentrating flux plates are inserted into the substrate; and the two ends of the permanent magnet are in seamless absorption connection with the end parts of the two concentrating flux plates respectively. The multipolar DC molded case circuit breaker has a rational design, a compact structure, a small volume and a rated operating voltage even capable of reaching a kilovolt level, and meets the requirements of electric motor coaches for public transportation and photovoltaic power generation and wind power generation systems on battery pack isolation and protection.

Description

technical field

[0001] The invention relates to a low-voltage electrical switch, in particular to a multi-pole DC plastic case circuit breaker improved on the basis of the structure of the existing AC plastic case circuit breaker single break point contact system. It is mainly used in power switching and circuit control places with rated working voltage up to 600V to kilovolt level. Background technique

[0002] At present, there are many types of DC circuit breakers mainly used in industrial and mining traction locomotives, power plants, battery power switching and circuit control, most of which are two-pole, and two or more poles are generally referred to as multi-pole. Generally, a two-pole (2P) circuit breaker has two contact rooms and two arc extinguishing chambers, and a four-pole (4P) circuit breaker has four contact rooms and four arc extinguishing chambers. A traditional DC circuit breaker mainly includes a single-break contact system, a thermal-magnetic tripping s...

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