GB904125A - Electric circuit interrupters - Google Patents

Abstract

904,125. Fluid-blast switches. WESTING- HOUSE ELECTRIC CORPORATION. Aug. 9, 1960 [Aug. 27, 1959], No. 27525/60. Class 38 (5). A switch comprises a metallic tank 179 containing a liquid medium which would be gaseous at room temperatures and pressures, a pair of terminal bushings 200 extending into the tank and carrying stationary contacts 205, an insulating interrupting tube 210 within the tank a pair of moving contacts 190 co-operating with the stationary contacts and a common actuating bar 186 carrying the moving contacts. Each contact 190 is connected by a conductor strip 191 to a movable pressure generating contact 189 co-operating with a fixed contact 229, the four pairs of contacts being in series. When the switch is opened by downward movement of the actuating bar 186, the arcs drawn at the contacts 189, 229 generate pressure within a magnetic shield 227 to force liquid medium through openings 221, passages 220 and openings 235 in orifice structures 212 to provide radial blasts against the arcs drawn between the contacts 190, 205. The arc-extinguishing medium may be CO 2 , SO 2 , SF 6 , SeF 6 , SOF 2 , CCl 2 F 2 , ClO 3 F, C 2 F 6 , C 3 F 8 , CClF 3 or CF 3 Br. The magnetic shield 227 permits shortening of the pressure generating arcs to avoid excessive pressure when interrupting high current arcs. The bar 186 may be actuated by the linkage shown in Fig. 3 or by bell-crank levers 243, Fig. 4, having rollers 242 co-operating with raceways 241 in a channel member 240 secured to the actuating bar 186. Figs. 1 and 2 (not shown) illustrate a three-phase multi-break circuit-breaker formed by six of the units described above mounted on insulating columns. Specification 853,683 is referred to.