Bbc Brown, Boveri & Company, Limited

Andreas Plessl

Karl Munzinger

Jurg Ischi

Jan G Vit

Jorg Peter

Denis Poole

A cast housing is provided for carrying switchgear components, such as a power switch or circuit-breaker, a busbar, a disconnecting switch and a grounding switch and bushings, to a multi-phase medium-voltage switchgear. It is substantially cuboid-shaped and is filled with an insulating gas. This cast housing is designed such that it may be used without substantial modifications in all possible designs of switchgear for a given switchgear voltage. This is achieved by the cast housing having large openings at the front wall and at the side surfaces adjoining the front wall and having a comparatively small opening at each of the rear walls and the top and bottom surfaces for each phase of a switchgear having from one to four phases. At the same time, the supply terminals of the phases of the power switch or circuit-breaker can be brought through the opening located in the front wall into the interior of the cast housing, in each case the phase conductors of the busbar can be led through the openings located in the side walls and either a bushing conductor, directed along a mid-axis of this opening, can be led through each of the remaining openings to a further live switchgear component, or this opening can be closed off by a cover or a cast wall.

Cast housing for medium-voltage switchgear

The gas-blast circuit breaker, which is preferably provided for switching medium-high voltages, has two arcing and two rated-current contacts each of which are located in a housing filled with insulating gas and operate in conjunction with each other. For purposes of a compact construction, electric connections, are carried into the interior of the housing transversely to the direction of movement of one moving contact of the two arcing contacts. The driving energy required for a switching process is intended to be kept as low as possible while retaining the compact construction. This is achieved by the fact that the moving rated-current contact is rotatably supported and that a drive, acting on the moving arcing and the moving rated-current contact has two rods which are pivoted at a driving crank, one of which rods is pivoted at the moving arcing contact and the other one of which is pivoted at the moving rated-current contact. In this arrangement, the two insulating rods are pivoted at the driving crank in such a manner that, during the disconnecting process, a thrust crank formed by the driving crank, one rod of insulating material and the moving arcing contact passes through a dead-center position before the disconnected condition has been reached.

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Niederrohrdorf, Switzerland

Andreas Plessl