| 摘要 |
An oil filled distribution transformer having a secondary circuit breaker utilizing a cantilevered stationary contact which is engaged by a movable contact for completing a series circuit therethrough. The cantilevered exposed stationary contact, which is surrounded by insulating oil, allows the oil in the transformer to rapidly return to the contact area after circuit interruption providing for faster arc extinction. The movable contact can be a bridging contact which forms a circuit between the cantilevered stationary contact and a second stationary contact mounted above a support base. The movable bridging contact is spring biased toward an open position separated from the stationary contact, but with the circuit breaker in the normally closed position is held in engagement with the stationary contact by a latching mechanism which is responsive to a bimetal or magnetic trip to allow the circuit breaker to trip open during overload conditions. The front cantilevered contact is completely surrounded by oil. During circuit interruption the oil in the contact area vaporizes forming an arc bubble of gas. Exposing the contact to allow free flow of oil into the area of the arc bubble allows for faster arc extinction and circuit interruption under fault conditions. |
