Siemens Aktiengesellschaft

Helmut Beier

Heiner Marin

Klaus Schuler

Rainer Bitsch

Joaquin-Conrado Bohrdt

In an electric high-voltage circuit breaker with a hydraulic drive, the piston rod, going through a seal, is brought out of the hydraulic cylinder in order to actuate the movable contact via a reversing gear and a switching rod. The piston rod is arranged in a protective tube and provided with a guiding ring which guides the piston rod in the protective tube. The piston rod is coupled to a fork head which engages the reversing gear. The hydraulic cylinder is located between two housings for drive parts, the interior spaces of which are heated and ventilated or exhausted. To prevent the formation of condensate water in the interior of the protective tube, there are provided in the hydraulic cylinder passages which connect the interior of the lower housing and the interior of the upper housing, respectively, to the interior of the protective tube. Thereby, the heated air is conducted from the lower housing via the interior of the protective tube into the interior of the upper housing. The electric high-voltage circuit breaker may be of the type using SF.sub.6 pressurized gas in an open air installation.

Electric high-voltage circuit breaker

In a gas pressure circuit breaker with two fixed contacts an insulation tube is in the path of the quenching gas flow during circuit breaking. The insulation tube is grooved internally and externally. Openings for the quenching gas flow are formed by intersection of the sufficiently deep inner and outer grooves at crossings. There results a ribbed body of low material intensity, which nevertheless is resistant to bending and torsion. Under mechanical (static and dynamic) and thermal stress the insulation tube exhibits a long life. The arc applying stress on the inner surface weakens the rib structure of the insulation tube comparatively little. The surface toward the arc has no web connections in the axial direction. Due to the resulting layering of insulating material and insulating or quenching gas, the resistance of the circuitbreaker to surface leakage current is increased.

Gas pressure circuit breaker

A contact system for a gas blast circuit breaker has a nozzle-shaped fixed first contact piece, a coaxially mounted nozzle-shaped axially movable second contact piece and a movable bridging element common to both contact pieces. Spring biasing serves to urge the end faces of the first and second contact pieces together in the breaker make position. The breaker driving means moves the bridging contact piece out of a position of electrical connection between the first and second contact pieces during the breaking process, before the second contact is separated from the first contact. The arc at breaking is thus drawn only between the first and second contact pieces which are fitted with graphite electrodes to resist burn-off. This protects the current paths which are intended to carry the rated current and the short circuit current in the make position from damage due to arcing. And since the contact elements of the bridging contact piece which transfer the rated current do not participate in guiding the arc, the dielectric strength of the arc gap is increased.

Contact system for gas blast circuit breakers

The invention is directed to a contact arrangement in a compressed-gas circuit breaker such as a blast-piston breaker. The contact arrangement includes two base contacts and a bridging contact member. One of the base contacts is movable as a function of the current to be interrupted and the motion is controlled by two electrodynamic coil systems. One coil system causes a shortening of the gap and the other coil system causes a reverse motion shortly before the zero crossing to establish the quenching distance.

Contact arrangement for an electric compressed-gas circuit breaker

A contact arrangement for an electric pressure-gas circuit breaker for interrupting an electric current includes two stationary contact pieces disposed so as to conjointly define a gap therebetween. A follower contact is arranged on one of the contact pieces in insulated relation thereto so as to be movable in a direction toward the other one of said contact pieces. A bridging contact member is movable between first and second positions for electrically joining the contact pieces in the first position and for running off of the one contact piece when moved in the above-mentioned direction toward the other contact piece to the second position thereby electrically separating the contact pieces. An electromagnetic actuator develops a force to propel the follower contact toward the other contact piece during the opening operation of the breaker. A spring associated with the follower contact receives resilient energy as the actuator means propels the follower contact in the direction toward the other contact piece. The follower contact is connected to the current supply for supplying current to the breaker through the electromagnetic actuator to define a bypass conducting path. The follower contact is arranged in the one contact piece so as to cause the bridging contact member to contact the follower contact when the bridging contact member runs off of the one contact piece thereby commutating the current to the bypass conducting path whereby the electromagnetic actuator becomes energized to develop the above-mentioned force.

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Berlin, Germany

Helmut Beier