A high voltage circuit-breaker comprising a housing defining a volume for an insulating gas, at least two making and breaking (M&B) units arranged therein, each M&B unit comprising a first and second contact element for forming an electrically conductive connection, at least the first contact element is movable along an axially extending switching axis of the high voltage circuit-breaker, and the first contact elements of the at least two M&B units are motion-coupled; a drive device connected to the first contact element of at least one M&B unit and configured for moving the first contact element along the switching axis over a moving distance for separating conductive connections; and a gas damper connected to the first contact element of the at least one M&B unit and configured for damping movement of the first contact element with a damping force increasing in relation to the moving distance.

Disclosed are an arc extinguishing unit and an air circuit breaker comprising the same. An arc extinguishing unit according to an embodiment of the present invention provides: 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; a magnet unit forming a magnetic field for changing a path of an arc formed between a fixed contact and a movable contact disposed to be spaced apart from the fixed contact, and disposed adjacent to the outermost grid adjacent to the fixed contact among the plurality of grids.

Disclosed are an arc extinguishing unit and an air circuit breaker comprising the same. An arc extinguishing unit according to an embodiment of the present invention provides: 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; a magnet unit forming a magnetic field for changing a path of an arc formed between a fixed contact and a movable contact disposed to be spaced apart from the fixed contact, and disposed adjacent to the outermost grid adjacent to the fixed contact among the plurality of grids.

A circuit breaker comprises a switching contact point configured by a fixed contact having a fixed contact point and a moving contact having a moving contact point, and an arc extinguishing chamber unit configured to extinguish an arc generated between the fixed contact point and the moving contact point. The switching contact point and the arc extinguishing chamber unit being arranged in a case. The arc extinguishing chamber unit includes a unit case and a plurality of grids arranged in layers in the unit case. The unit case includes a first case arranged near the switching contact point and configured to hold the plurality of grids and a second case configured to close an opening part of the first case and detachably coupled to the first case, and formed with an exhaust hole configured to exhaust arc gas to an outside.

A circuit breaker comprises a switching contact point configured by a fixed contact having a fixed contact point and a moving contact having a moving contact point, and an arc extinguishing chamber unit configured to extinguish an arc generated between the fixed contact point and the moving contact point. The switching contact point and the arc extinguishing chamber unit being arranged in a case. The arc extinguishing chamber unit includes a unit case and a plurality of grids arranged in layers in the unit case. The unit case includes a first case arranged near the switching contact point and configured to hold the plurality of grids and a second case configured to close an opening part of the first case and detachably coupled to the first case, and formed with an exhaust hole configured to exhaust arc gas to an outside.

A circuit breaker, comprising a housing, an operation assembly, an arc extinguishing device, and a transmission mechanism. The housing has, in a first direction, a bottom and a top opposite to each other, an accommodation portion recessed from the top to the bottom, and an accommodation cavity semi-surrounding the accommodation portion; a rotating wheel and a movable contact connected to the rotating wheel are provided in the accommodation cavity close to the top and adjacent to the accommodation portion in a second direction, wherein the first direction intersects the second direction; the operation assembly is rotatably and detachably connected to the top of the housing; the arc extinguishing device comprises an arc extinguishing chamber located in the accommodation cavity and close to the bottom of the housing. The circuit breaker can avoid interference between the transmission mechanism and other components while increasing the size of the arc extinguishing chamber.

A circuit breaker, comprising a housing, an operation assembly, an arc extinguishing device, and a transmission mechanism. The housing has, in a first direction, a bottom and a top opposite to each other, an accommodation portion recessed from the top to the bottom, and an accommodation cavity semi-surrounding the accommodation portion; a rotating wheel and a movable contact connected to the rotating wheel are provided in the accommodation cavity close to the top and adjacent to the accommodation portion in a second direction, wherein the first direction intersects the second direction; the operation assembly is rotatably and detachably connected to the top of the housing; the arc extinguishing device comprises an arc extinguishing chamber located in the accommodation cavity and close to the bottom of the housing. The circuit breaker can avoid interference between the transmission mechanism and other components while increasing the size of the arc extinguishing chamber.