Compact high-current vacuum circuit interrupter comprising a metal housing that is electrically connected to one contact of the interrupter

摘要

A vacuum interrupter having a current interrupting rating exceeding 20, 000 amperes r.m.s. comprises an evacuated envelope and first and second disc-shaped contacts within the envelope. The envelope comprises a metal housing having a generally cylindrical portion surrounding said contacts and electrically connected to said first contact. The space between said cylindrical portion and said second contact is so small that during the interruption of currents above 20,000 amperes r.m.s., 25% or more of the arcing current frequently will flow between said housing and said second contact and bypass said first contact. Arc-revolving means associated with the second contact causes any arc between the outer periphery of the second contact and the cylindrical housing portion to revolve about the second contact.P PAn electric bus located near the envelope is normally electrically connected to said first contact to carry current that flows between the contacts. Means located outside the evacuated envelope provides an electrical connection between the bus and the metal housing that is capable during interruption of carrying without damage the full rated interrupting current of the interrupter. The first contact is a movable contact mounted on a contact rod that is sealed to the housing by a flexible metal bellows located within the housing.