Modular suction-gas-cooled magnetic blast circuit breaker

Abstract

A gas-cooled magnetic blast circuit breaker made up of a plurality of identical modules. Each module is a flat body made of electrically non-conductive air-permeable material and is formed with an upper and a lower arc breaking chamber, the chambers being separated from one another by a central wall of the body. An electrically conductive stationary contact member is provided in each chamber, each member extending through the body for connection to the power line on opposite faces of the body. There is also provided an electrically conductive dual contact member which is pivotally mounted across the central wall of the body, this dual member having a contact gate at each end, each gate being located in one of the chambers to cooperate with the stationary contact member in that chamber. A pivotable shaft, made of electrically non-conductive material, extends transversely through the body and is connected to the dual contact member to pivot it whereby to move the contact gates simultaneously into and out of electrical junction with the stationary contact members so as to make and break current in the power line. There is provided a coil which is energizable by the current in the power line and which is adapted to create a magnetic field suitable to blow, into the arc chambers, arcs that are formed when the contact gates are moved away from the stationary contact members. The chambers are formed so as to be provided with guideways extending from outside the body to the contact members so that air may be sucked into the chamber by the blown arcs so as to cool the contact members.