The present disclosure relates to an arc extinguishing unit of a molded case circuit breaker with a barrier provided between a fixed contact and a movable contact when a circuit is cut off. The arc extinguishing unit includes fixed contacts fixed to part of a base assembly case; movable contacts that contact or are separated from the fixed contacts; and an arc extinguishing part that extinguishes an arc generated when the movable contacts are separated from the fixed contacts. The arc extinguishing part includes a pair of side plates; multiple grids installed at a fixed interval between the side plates; and arc barriers each rotatably installed on the side plates, and configured to open between the movable contacts and the fixed contacts by being rotated when a current flows on the circuit, and to close between the movable contacts and the fixed contacts when the current is cut off.

An unit has a plurality of arc quenching plates and an electrically isolative housing, the plurality of arc quenching plates adjacent to each other are spaced to form an arc channel. Each one of the plurality of arc quenching plates has a mounting portion and a receiving portion, the receiving portion has a distributing part, the distributing part has a through hole penetrating through the receiving portion and an inclined plane protruding from the receiving portion, the inclined plane is arranged to a side of the through hole away from an arc entrance and extending to the arc entrance, an angle between the inclined plane and the receiving portion is an acute angle, a root of the inclined plane is continuous with the receiving portion. An inclined plane of a first arc quenching plate is interlacing and opposite with an inclined plane of a second arc quenching plate.

The present disclosure relates to an arc extinguishing device of a molded case circuit breaker which includes a fixed contactor fixedly provided on part of a base assembly case; a movable contactor brought into contact with or separated from the fixed contactor; and an arc extinguishing unit configured to extinguish an arc generated when the movable contactor is separated from the fixed contactor, and the arc extinguishing unit including a pair of side plates provided on the base assembly case; and a plurality of grids provided to have a predetermined distance between the pair of side plates, and the grid including a first grid formed with a first cutout portion on a first side surface where an arc is generated; and a second grid formed with a second cutout portion having a depth different from that of the first cutout portion on a second side surface where an arc is generated.

The present disclosure relates to an arc extinguishing unit of a molded case circuit breaker with a barrier provided between a fixed contact and a movable contact when a circuit is cut off. The arc extinguishing unit includes fixed contacts fixed to part of a base assembly case; movable contacts that contact or are separated from the fixed contacts; and an arc extinguishing part that extinguishes an arc generated when the movable contacts are separated from the fixed contacts. The arc extinguishing part includes a pair of side plates; multiple grids installed at a fixed interval between the side plates; and arc barriers each rotatably installed on the side plates, and configured to open between the movable contacts and the fixed contacts by being rotated when a current flows on the circuit, and to close between the movable contacts and the fixed contacts when the current is cut off.

The invention relates to an arc quenching plate for quenching arcs. The arc quenching plate comprises a mounting portion suitable for mounting and a receiving portion suitable for receiving arcs, the receiving portion comprises a distributing part suitable for separating arcs, the distributing part comprises a through hole penetrating through the receiving portion and an inclined plane protruding from the receiving portion, the inclined plane is arranged to a side of the through hole away from an arc entrance and extending to the arc entrance, an angle between the inclined plane and the receiving portion is an acute angle, a root of the inclined plane is continuous with the receiving portion. The arc quenching plate and the arc quenching unit of the present invention have following benefit, in the same space, an arc can be separated into much more pieces of short arc.

A self-resetting current limiter includes: a first connecting contact for bringing the current limiter into contact with a first electrical conductor a second connecting contact for bringing the current limiter into contact with a second electrical conductor; a first movable contact member; and a second movable contact member, wherein the first and the second movable contact members are electrically interconnected in a first position of the first and the second movable contact member, such that a current path between the first and the second connecting contact is closed, and wherein the first and the second movable contact members are separated from one another in a second position of the first and the second movable contact member, such that the current path between the first and the second connecting contact is interrupted.

The present disclosure relates to an arc extinguishing device of a molded case circuit breaker which includes a fixed contactor fixedly provided on part of a base assembly case; a movable contactor brought into contact with or separated from the fixed contactor; and an arc extinguishing unit configured to extinguish an arc generated when the movable contactor is separated from the fixed contactor, and the arc extinguishing unit including a pair of side plates provided on the base assembly case; and a plurality of grids provided to have a predetermined distance between the pair of side plates, and the grid including a first grid formed with a first cutout portion on a first side surface where an arc is generated; and a second grid formed with a second cutout portion having a depth different from that of the first cutout portion on a second side surface where an arc is generated.

Circuit breakers are configured with line terminal geometry that drives the current from a terminal input in a direction that can reduce electromagnetic forces and that can also or alternatively include an arc chute assembly that can reduce repulsive electromagnetic forces to improve the operating level of withstand current (Icw).

Disclosed are an arc extinguishing unit and an air circuit breaker comprising the same. The present disclosure provides an arc extinguishing unit, including: side plates spaced apart from each other and disposed to face each other; a plurality of grids disposed between the side plates, spaced apart from each other, and coupled to the side plates, respectively; and a grid cover located above the grid and covering the grid, wherein the grid includes a grid leg extending downward from both ends in the width direction so that an induced magnetic field can be formed by an arc generated when a fixed contact and a movable contact are spaced apart.

Disclosed are an arc extinguishing unit, a circuit breaking unit, and an air circuit breaker including the same. The present disclosure provides an arc extinguishing unit, a circuit breaking unit, and an air circuit breaker, including: side plates spaced apart from each other and disposed to face each other; a plurality of grids disposed between the side plates, spaced apart from each other, and coupled to the side plates, respectively; and a grid cover located above the grid and covering the grid, wherein the grid includes a grid leg extending downward to surround from both sides a protruding contact disposed to extend upward from a movable contact; and a first protective part formed to surround at least a portion of the grid leg at a lower portion of the grid leg.