GB307062A - Improvements in or relating to electric switchgear structures - Google Patents

Abstract

307,062. Sargent & Lundy, Inc., (Assignees of Rossman, A. M.). March 3, 1928, [Convention date]. Couplings. - To provide against interphase short circuits, bus-bars in the form of cables are individually insulated by being composed of conductors 1A, 1B, 1C, Fig. 1, covered with fibrous or like insulation 2, itself immersed in self-healing insulation, e.g. light oil 5 contained in a copper &c. sheath 3, which is thin and so is supported on a framework 4, which restores the rigidity lost by economizing copper. The individually insulated busses can now be brought closer together than is normal in the isolated phase system, while the liquid and copper surrounding the conductor help to dissipate heat. In practice, the framework supports the system well clear of the ground, the bus-bars being above and the circuit-breakers, transformers, &c. below, the actual supporting platform. The cables are made in standard lengths connected by junction boxes which serve also for attachment to the frame. Mounting and removal of the individual cable sections is facilitated by staggering them as shown at 30, 31, 32, Fig. 4, adjacent ends being joined by vertical connections. Electrical continuity of the sheaths is prevented by ' means such as insulating gaskets suitably interposed between sections. Distance pieces are used to keep the inner tubes 2 clear of the sheathing 3. The ends of two adjacent lengths 360, 380, Fig. 9, of the sheath are secured by flanges 361, 381 to members bolted to the two elements 368, 370 of what may be called a sliding spigot and socket joint, these elements carrying between them a flexible diaphragm member 366 secured by soldering and by clamps 373 and protected against damage by a thin metal cylinder 383. Similar means is employed to join a sheath length to a junction box. Specification 299,335 is referred to. The Specification as open to inspection under Sect. 91 (3) (a) describes and shows, Figs. 26 (Cancelled) and 27, a conductor comprising a sixstrand cable wrapped round a central rod, the ends 343 of each strand 344 being triangular with a spider 342 holding them apart, while a copper casting 345 surrounding the ends is bolted to a lug 346. This subject-matter does not appear in the Specification as accepted.