GB464767A - Improvements in electrical switchgear - Google Patents

Abstract

464,767. Switchgear structures. WHITEHEAD, G. E., and WHITEHEAD'S ELECTRICAL INVENTIONS, Ltd. Oct. 21, 1935, No. 29053. [Class 38 (v)] Switchgear, particularly for voltages up to 11 kv., comprises an oil circuit-breaker 1 of the downwardly movable bridge type 8 located at the front of the gear, with isolating switches 13 disposed above the breaker 1 and connecting the terminals of the latter with conductors 16, 20 in a transformer chamber 3, the conductor 20 extending into a cable entry box 4 at the rear of the gear, and conductor 16 being connected by a vertical conductor 17 behind the breaker 1 to a busbar within a chamber 5 located substantially underneath the breaker. A separate unit may be provided for each pole of the system, or the unit may be constructed as a multi-pole gear, the drawing showing one phase of a three-phase unit. The breaker comprises a lowerable tank 6, and fixed contacts 10, which may be arranged as described in Specification 464,643 and are carried on a member 12, which is lowerable to isolate the 'breaker 1 by withdrawing the plug contacts 13 from fixed socket contacts 14, 15 preferably arranged as described in Specification 409,085. Busbar connector 16 and the upper ends of contacts 14, 15 are embedded in solid, oilresisting insulation located in chamber 3 up to the level 26, whereas the part of the chamber 3 housing the cable-connector 20, in which the current transformer 21 is incorporated, contains oil. Conductor 17 is shrouded in insulation 18 at the upper part, and the bare lower end is adapted to be connected by socket contacts 32, 34 and a metal sleeve 31 with a plug contact 35 on the busbar connector 28. Sleeve 31 is shrouded in insulation 36 and the sleeves 31, 36 of all phases are carried in a frame 37 which is movable upwards by screwed rods and bevel gearing to disconnect 34 from 35 and, by a further movement, to bring the upper end of sleeve 31 into engagement with a tubular contact 38 which is earthed at 39 to the casing 40. Chamber 5 is preferably filled with solid insulation. Specifications 286,429 and 322,094, [both in Class 38 (v)], are referred to, and the Provisional Specification refers also to Specification 392,926.