GB327807A - Improvements relating to electric switching arrangements for ring main circuits - Google Patents

Abstract

327,807. Drake & Gorham, Ltd., Harmer, A. F., Holding, G. H., and Pengelly, P. J. Feb. 13, 1929. Switching systems.-A branch circuit (for example a consumers' circuit 3a, 3b, 3c) is taken off a ring-main distribution system 1a, 1b, 1c at a point between two independently-operable oil circuit-breakers B<1>, B<2> located in the ring main. As shown in Fig. 1, where the circuits of one of the phases are indicated, the circuit-breakers, which are of the kind described in Specification 304,386, [Class 38 (v), Electric switches &c.], are connected to the ring main through main isolating switches S<1>, S<2>, and the branch circuit connected to the mid-point through a branch isolating switch S<3>. The switchgear employed is shown in Fig. 2 ; the isolating switches S<1>, S<2>, S' which are operated by a removable handle 23 are interlocked in known manner with the oil circuitbreakers B<1>, B<2>, which are provided with operating handles 21 and tripping mechanism 22. The oil tank 24 is interlocked with the isolating switches so that it can be lowered only when the isolating switches are in their open position. A further circuit-breaker may be provided in the branch circuit and be interlocked with the two main circuit-breakers so as to open when they both open and to be prevented from reclosure until one or other of them has been re-closed.