Westinghouse Electric Corporation

John F Cotton

Raymond E Wien

Jack G Hanks

Nicholas A Salemi

Donald J Ristuccia

Theodore Gogniat

A ganged, multiple pole circuit breaker in which the multiple poles of each circuit breaker are mechanically related to a single operating point on the associated breaker. Their single operating points are pivotally related to a first common pivot point, which is fixed in relation to a common frame which supports both circuit breakers. Their single operating pivot points are additionally pivotally related to a second common pivot point. A guide arrangement, fixed to the common frame, guides the second common pivot point in a predetermined rectilinear path when actuated by an operating mechanism which includes a shaft arranged to extend through a transformer tank wall to a master operating handle. The guide arrangement prevents any motion of the second common pivot point in a direction lateral to the rectilinear path.

Ganged circuit breaker arrangement

A secondary circuit breaker for a distribution transformer characterized by electrical inductive apparatus within an oil-filled housing, and circuit interrupter for controlling current flow through the transformer and comprising a releasable latch arm, trip means operable upon overload conditions to release the latch arm, a latch lever between the trip means and the latch arm and comprising the only operable part therebetween, and the latch lever having a cam surface for latching and unlatching the releasable arm.

Secondary circuit breaker for distribution transformer

An oil-filled distribution transformer having a primary disconnect switch disposed within the housing and utilizing two movable bridging contacts and four stationary contacts for completing a series circuit therethrough. The switch includes a trip mechanism, a bimetal element isolated from the current path through the switch and responsive to the temperature of the oil to activate the trip mechanism upon overtemperature condition, and a float mechanism attached to the switch and cooperating with the trip mechanism so that the float assembly will activate the trip mechanism when the oil level within the housing drops below a predetermined value.

Distribution transformer having a primary disconnect switch

A circuit interrupter including a releasable latch restrained by a stamped metal rotatable cam having a latching surface in sliding contact with the latch member. The rotatable cam is inclined at an angle to the axis of rotation so as to cause only the smooth portion of the latching surface produced by the shearing action of the stamping process to contact the latch member. The rough portion of the latching surface produced by tearing action of the stamping process is not in contact with the latch member, thereby eliminating the need for a machining operation to provide a low friction contact surface with the latch member.

Circuit interrupter including low friction latch

A circuit breaker particularly adapted for use in an oil filled distribution transformer includes an improved bimetal trip actuator which exhibits greater deflection for a given degree of power dissipation. The trip actuator includes a planar bimetal element held relatively stationary at one end and free to deflect at the other end in response to overload current conditions through the circuit breaker. The bimetal element is constructed to have a higher power dissipation in proximity to the stationary end than in proximity to the deflecting end.

Distribution transformer secondary circuit interrupter having an

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.

Distribution transformer secondary circuit breaker having cantilevered

A circuit interrupter having a magnetic trip element which is integral with the latch. The disclosed circuit interrupter is provided with a bimetal and a magnetic trip element directly connected to the latch of the circuit interrupter which is drawn towards the bimetal, unlatching the circuit interrupter when current flow therethrough exceeds a high overload level. The disclosed circuit interrupter is particularly adaptable for use on a distribution transformer. A movable bridging contact for completing a series circuit between two stationary contacts is provided. The movable bridging contact is spring biased towards an open position separated from the stationary contacts, but with the circuit interrupter in the normally closed position is held in engagement with the stationary contacts by a latching mechanism which is responsive to the bimetal or magnetic trip element to allow the circuit breaker to trip open during overload conditions. The magnetic trip element is formed integral with the latching mechanism to reduce time delay before operation. A plurality of poles are operated using only one operating mechanism by connecting the elongated operating arms with a strong metallic member for simultaneous operation of all poles. The bridging contact is disposed near the end of an elongated operating arm which is linked to the circuit breaker operating mechanism. Each pole of the circuit interrupter is provided with a bimetallic trip element. The magnetic trip element can be formed from a single piece having a plurality of legs each disposed in proximity with the bimetal of one pole.

Integral magnetic trip and latch for a circuit interrupter

A distribution transformer having a secondary circuit breaker utilizing a movable bridging contact between two stationary contacts for completing a series circuit therethrough. The movable bridging contact is spring biased towards an open position separated from the stationary contacts, but with the circuit breaker in the normally closed position is held in engagement with the stationary contacts by a latching mechanism which is responsive to a bimetal or magnetic trip element to allow the circuit breaker to trip open during overload conditions. The conducting bridging contact completes a series circuit through the circuit breaker which opens during circuit interruption. The secondary circuit breaker can also, if desired, be provided with a signal-light circuit which activates a signal light, on the exterior housing of the transformer, when current through the circuit breaker exceeds a low signal overload value which is less than the trip value. The signal light circuit is reset by turning the operator handle, which is located on the transformer housing, past the on position away from the off position. An emergency overload control is provided for increasing the tripping level of the circuit breaker during selected overload periods. The bridging contact is disposed near the end of an elongated operating arm which is linked to the circuit breaker operating mechanism. A plurality of poles are operated utilizing only one operating mechanism by connecting the elongated operating arms with a strong metallic member for simultaneous operation of all poles. The single signal light provided for each multi-pole circuit breaker can be activated by the bimetals of any one of the individual poles.

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Athens, GA, United States of America

John F Cotton