ARC extinguishing unit for molded case circuit breaker

摘要

There is provided an arc extinguishing unit of a molded case circuit breaker (MCCB) having a structure in which grids and side plates forming an arc chamber are coupled in an inserted manner, facilitating an operation, and intervals of grids are uniformly maintained and a configuration of the grids is not damaged, thus maintaining stable performance and allowing for maintenance.

主权项

1. An arc extinguishing unit of a molded case circuit breaker (MCCB) including a casing, a stator connected to a load or a power source, and a mover rotatably installed within the casing such that it is brought into contact with or separated from the stator, the arc extinguishing unit comprising:
a plurality of grids arranged at predetermined intervals in an outer side of a movement trace of the mover; a pair of side plates including two-stage flat plates having a step cross-section and including a first flat plate fixing one end portions of the grids to form an arc chute and a second flat plate forming an arc chamber together with a lower surface of the grids; and a pair of lateral magnets fixedly installed on rear surfaces of the second plates, wherein an intermediate protrusion formed on a lateral surface of each of the grids has a first stop projection formed on one side thereof, a second stop projection is formed on a lower surface of each grid, a first installation hole is formed on the first plate to allow the intermediate protrusion to be inserted therein, and a connection portion formed between the first flat plate and the second flat plate has a second installation hole to which the second projection is inserted.