GB759739A - Improvements relating to high-voltage switchgear - Google Patents

Abstract

759,739. Switchgear structures. REYROLLE & CO., Ltd., A. Dec. 15, 1954 [Sept. 16, 1953], No. 36388/54. Divided out of 759,708. Class 38(5) High-voltage duplicate bus-bar switchgear provided with circuit-breakers of the fixed type having associated switches for isolating them from the bus-bars and for selectively connecting them to the busbars, is provided with an additional switch associated with one of the bus-bars which has an "off" and two or more "on" positions. The additional switch, which may be of the pivoted bushing type disclosed in Specification 759,708, may be arranged to connect its associated bus-bar alternatively to corresponding sides of each of two or more of the circuit-breakers, to each side of one of the circuit-breakers, or to connect a line terminal either direct to the associated bus-bar or to the line side of the associated circuit-breaker. As shown in Fig. 3, two line units A, B, may each comprise a circuit-breaker so connected through line isolators 64 to line 60. Each circuitbreaker is provided with a bus selector switch 36, by which it may be connected to either of the bus-bars 33, 34, or isolated. An isolator 50 may connect the bus-bar 34 direct to either line 60, providing means whereby each circuit-breaker may be isolated and by-passed. In the arrangement shown in Fig. 4, two isolator bushings 70 are provided, each of which may connect the bus-bar 34 either to the upper terminal of the associated circuit-breaker 30 or direct to the line 60. By this arrangement full protection is provided by the circuitbreakers 30 while the load is transferred from one set of bus-bars to the other. Fig. 5 shows another circuit-breaker by-pass arrangement in which a circuit-breaker 80 is connected through a selector switch 81 to one or other of bus-bars 82, 83. A line 87 is connected through a second switch 88 either to bus-bar 83 or to the line terminal of the circuit-breaker.