CIRCUIT BREAKER AND METHOD FOR ASSEMBLING ARC EXTINGUISHING CHAMBER UNIT IN CIRCUIT BREAKER

原文（中文）

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.