Patent attributes
A pressure trip device for a circuit breaker comprises a plurality of single pole switching units, each unit corresponding to each electrical phase hermetically mounting movable contactors and fixed contactors in an insulated case in order to switch electrical circuits according to each phase, having arc gas exhaust port, and connected to one another by a shaft; a switching mechanism connected to one of the single pole switching units for contacting or separating the movable contactor of the connected single pole switching unit to/from the fixed contactor of the connected single pole switching unit; a trip bar connected to the switching mechanism for tripping the switching mechanism; a gas pressure shooter facing the trip bar, and perpendicularly movable between a position for rotating the trip bar by a pressurization and a position separated from the trip bar; and a protrusion wall portion having a pair of wall portions facing to each other and perpendicularly extending from at least one outer surface of each case of the single pole switching units, having one wall portion for connecting lower ends of the pair of wall portions to each other, and forming a gas pressure storing space for supporting the gas pressure shooter to be perpendicularly movable and connected to the arc gas exhaust port. Accordingly, the circuit breaker is tripped faster than the conventional one using a tripping process by mechanisms of multi-step.
