Westinghouse Electric Corporation

Electric Power Research Institute Incorporated

Northern Engineering Industries Plc

Charles F Cromer

Willie B Freeman

Kue H Yoon

Joseph R Rostron

William H Fischer

Robert L Hess

Thomas Kelsey

Sylvester J Dropik

Kent D Daschke

Michael G Caithness

Lee E Berkebile

Paul J Yuran

An improved circuit-interrupter of either the vacuum-type, or of the compressed-gas type, is provided having a shunting capacitance around, or electrically paralleling, the separable power contacts of the main power interrupter. In series with the said electrically-shunting capacitance is capacitor-isolating disconnecting switch, which interrupts the residual capacitance current at a subsequent point in time following the interruption of the main-power current in the main-power interrupting unit. The present invention may be applied not only to vacuum interrupters, but also to compressed-gas circuit-interrupters of either the double-pressure gas type, or the single-pressure gas type, such as the so-called 'puffer' gas type, creating gas flow by relative piston-and-cylinder operation.

Circuit-interrupters having shunting capacitance around the separable

A circuit interrupter uses a dielectric liquid such as sulphur hexachloride to extinguish arcs in an interrupter. The liquid is injected at a relatively high pressure by a pump piston with a relatively high mass and an accumulator acts as a pressure fly wheel to effectively reduce high pressure maximums and increase low pressure minimums because of the much lower mass of the accumulator piston. In addition, a double fluid flow interrupter is provided.

Circuit interrupter using dielectric liquid with energy storage

A gas-insulated circuit interrupter includes stationary and movable contact assemblies which are cooperable with each other to transmit or interrupt electrical current. Means are provided for moving the movable contact assembly, and for establishing a flow in the circuit interrupter during an opening interruption to estinguish the arc which is drawn between the stationary and movable arcing contacts. A hollow insulating nozzle is utilized for directing gas flow. The interior surface of the nozzle is shaped so as to direct a flow of insulating gas to blast into the arc, and the exterior surface of the nozzle is contoured such as to deflect the flow of insulating gas away from the movable main contacts.

Gas-insulated circuit-interrupter having improved insulating nozzle

A minimum liquid circuit interrupter provides a relatively remote cooled storage unit for the dielectric liquid and fills a cylinder which is in close proximity to the insulating nozzle of the interrupter, the cylinder being driven at one end by a piston and closed at the other by the moving contact of the interrupter.

Circuit interrupter using a minimum of dielectric liquid

An improved puffer-type, compressed-gas circuit-interrupter is provided having an improved double-flow operation, and improved cooling means for cooling the compressed gas prior to its ejection through the insulating movable nozzle and into the established arc. Additionally, the instant invention comprises the use of flexible movable arcing contact fingers with a surrounding cylindrical guide-valve sleeve to prevent premature leakage of compressed gas through the longitudinal finger slots provided in the movable arcing contact fingers during the opening operation. Such movable cylindrical guide-valve sleeve may be either insulating or metallic, as desired.

Double-flow puffer-type compressed-gas circuit-interrupter

An improved circuit interrupter for high voltage and low current provides reactor and capacitor switching functions with fewer serial interrupters. Improved electrical field configuration is provided by moving and stationary contact shields, surrounding the main contacts, which aid the plain break operation of the device by elimination of critical points of dielectric stress. The plain break feature provides less mechanical complexity and consequent higher reliability.

High voltage plain break circuit interrupter

An improved puffer-type gas-blast circuit-interrupter is provided having a movable operating cylinder assembly movable over a relatively-fixed piston structure. A high compression ratio is obtained during the opening operation by minimizing the 'dead' volume of arc-quenching gas within the movable operating cylinder, and an efficient gas-flow path through the movable cylinder assembly smoothly converges through the movable nozzle throat-area into the drawn arc. A high electrical withstand capability is accomplished by using a generous radius on the lower ends of external stationary main contact fingers, and by shrouding, or shielding the stationary contact probe within the surrounding shield of the stationary contact fingers. The circuit-interrupter of the present invention is adapted for various current ratings, such as 2,000 amperes, 3,000 amperes, or 4,000 amperes, for example, by varying the number of stationary main contact fingers used surrounding the movable operating gas-cylinder. High-interrupting performance is obtained with a reduced residual gas volume at the end of the opening stroke, and, consequently, a higher gas-compression ratio is obtained. The gas-flow downstream of the nozzle throat area is confined within the cluster of stationary main contact fingers, and this cools the ejected gas to prevent voltage breakdown to electrical members at another potential. Open venting ports are provided at the upper end of the stationary contact finger cluster to prevent stagnation of the hot arced gas flowing into the stationary contact finger cluster, which thereby permits the hot arcing gases to be blown out of the way to insure good interrupting performance and a high breakdown value.

Puffer-type compressed-gas circuit interrupter

An improved puffer-type, compressed-gas, circuit-interrupter is provided having an improved separable contact structure with resilient stationary contact fingers biased inwardly upon the movable tubular venting arcing contact, the latter moving with a movable operating cylinder over a relatively-fixed piston structure, and carrying an insulating nozzle therewith. The movable tubular venting arcing contact is disposed upstream of the movable nozzle structure, and does not impede the gas flow through the nozzle structure, as generated by the relative movement of the operating cylinder over the relatively-fixed piston structure. Preferably, the relatively-stationary resilient contact fingers, are encircled by a tubular venting stationary contact support, being fixedly secured thereto, the arrangement functioning to cause contact interengagement between the stationary resilient contact fingers and the movable tubular arcing venting contact, so that upon circuit-interrupter opening movement, an arc is established between the forward tips of the resilient stationary contact fingers and the upper extremity of the movable tubular venting arcing contact. Double gas-flow occurs through both the stationary and movable tubular venting contacts, and yet the constricted portion of the insulating hollow movable nozzle may be increased only slightly by the relocation of the contact fingers to the stationary supporting portion of the interrupter. Additionally, the elimination of the usual upstream movable finger-cluster obstruction allows a corresponding reduction in the size and mass of the moving cylinder supporting spider.

Puffer-type compressed-gas circuit-interrupter having improved separable

An improved puffer-type compressed-gas circuit-interrupter is provided having double-flow gas-flow conditions occurring in opposite directions within the arcing region, and providing thereby adaptability for high-current interrupting duty. Additional features moreover include a relatively-stationary tubular arcing contact for improved venting of the hot arcing gases, secondary circumferentially-disposed movable contact fingers making contacting engagement with said tubular stationary venting arcing contact improved main contact structure.

Double-flow puffer-type single-pressure compressed-gas

An improved compressed-gas-type of circuit-interrupter is provided having a pair of separable contacts and a cooperating nozzle structure, through which the established arc is drawn. A spring-biased sleeve-valve surrounds at least one of these separable contacts, and extends at times into the orifice throat in the closed-circuit position of the device, and also during a portion of the opening operation, thereby blocking any gas flow through the throat of the orifice device in such blocking position of the sleeve-valve. The aforesaid sleeve-valve is preferably attached by a lost-motion mechanical connection with the associated captive contact, which it surrounds, so that during an intermediate portion of the opening operation, the sleeve-valve is physically picked up on the opening stroke by the aforesaid captive contact, or, alternatively, limited in its blocking action, and withdrawn out of the orifice throat upon take-up of the lost motion, thereby unblocking the said throat and thus permitting a flow of gas therethrough.

Compressed-gas circuit-interrupter having a sleeve-valve for temporarily

An improved puffer-type gas-blast circuit-interrupter is provided having a movable operating cylinder assembly movable over a relatively-fixed piston structure. A high-compression ratio is obtained during the opening operation by minimizing the 'dead' volume of arc-quenching gas within the movable operating cylinder, and an efficient gas-flow path through the movable cylinder assembly smoothly converges through the movable nozzle throat area into the drawn arc. The improved puffer-type interrupter of the present invention, additionally, is provided with a shorter insulating nozzle than in conventional 'puffers' to provide a more efficient gas path; and finally, a continuous annular stationary piston configuration requires no orientation procedures for assembly operations.

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Penn Township, PA, United States of America

Charles F Cromer