Patent GB-287544-A (GB)
Title: Improvements relating to electric switchgear
IPC: H02B13/02
Filed: 1928-02-02
Abstract: 287,544. Allis-Chalmers Manufacturing Co., (Assignees of Nye, H. V.). March 24, 1927, [Convention date]. Sliding switch-carriage arrangements. - Metal-clad switchgear installations comprise a number of adjacently disposed units supported on side frames each of which consists of two half frames releasably connected together to give the required rigidity and strength. As shown in Figs. 1 and 2 the draw-out switchgear units 1, 2 are supported on side frames 12'. 12<2>, 12<3>, each comprising a pair of side frames a, b formed of pressed metal flanged at their edges and welded at the corners which are secured back-to-back together by bolts 50a and are separated by distance pieces 50. The movable truck carrying the oil switch 15 is provided with rollers 14 moving along the upper flanges of the side plates, the truck being operated through rack and pinion gear 18, 19. The switch connections pass through a hood 17 to terminal connections adapted to engage with conductors in the fixed bus-bar sockets 4 and with sockets 7 or 9 corresponding to alternative outgoing feeders. The casings 3, 5, 8 carrying the fixed sockets are supported on the side plates a, b flanges 11 being formed for this purpose on the cable outlet box 10 extending downwardly from the casing 8. The bus-bar chambers 3 and 77 of adjacent units are connected by joint members 36 so that the bus-bars in passing between the units are totally enclosed and the inlet box 54 for the supply feeder is supported on the outer plate b of the support 12<3>. An instrument board 32 is supported on a column extending upwardly from the chamber 5 and a casing 65 for the potential transformer is also supported by this column. Connections to the instruments and potential transformer pass through a conduit 64 leading from a junction box 63 which is connected by further conduits 66, 62 and 58 to further junction-boxes 67, 59 and 55 carrying the wiring for the control circuits. The junction box 66 is connected bv a conduit 69 to a box 70 containing control switches and by a conduit 68 to the outlet box 6 for the upper feeder which contains series transformers. The box 59 carries a socket 60 engaging a corresponding member 61 on the movable truck to enable the oil switch tripping circuit to be completed. The box 55, which is secured to one of the side plates b is connected by a conduit 57 to a fuse box 56 similarly secured and by a conduit 72 to a relay panel (not shown). The lower flanges of the side plates are reinforced by angle iron, the side frames being braced by diagonal cross braces 71. The units may be assembled separately and transported singly or in groups as for example in a group of two as shown. To maintain units of such a group in position during transport channel members 37, 38 are bolted along the lower ends of the side plates and angle iron supports 33, 35 bolted along the front and rear of the side frames. When, however, the units are placed in their permanent location as shown in Fig. 1 angles 40, 41, 46, 47 which are welded to the lower sides of the frames are embedded in concrete and channel members 37, 38 rest on wooden blocks 48. Thus the temporary supporting members 37. 38 can be removed before the trench 49 containing the units is concreted in. The supporting angles 33. 35 may then be removed after the units have been secured in position.