Patent ID: 8390406

Claim:
A mold cased circuit breaker comprising: a casing; a switching unit located in the casing and configured to open or close an electric circuit; movable and stationary contactor units located within the casing; an arc-extinguishing unit, wherein the arc-extinguishing unit comprises: a pair of side plates facing each other and spaced apart from each other; at least two first grids arranged between the pair of side plates and spaced apart from each other at preset intervals; and a second grid coupled to upper ends of the pair of side plates, spaced apart from the first grids and comprising a bent portion with a preset angle, wherein the casing comprises an accommodating portion configured to accommodate the arc-extinguishing unit therein and a barrier defining a portion of an outer wall of the accommodating portion, the barrier protruding toward the arc-extinguishing unit, and wherein one side surface of the second grid is configured to contact the barrier.