GB1005259A - Bus structure enclosure - Google Patents

Abstract

1,005,259. Bus structures; couplings. CANADIAN WESTINGHOUSE CO. Ltd. July 30, 1963 [Aug. 25, 1962], No. 30078/63. Headings H2C and H2E. A polyphase bus structure comprises three parallel tubular conductors 5, 6, 7 supported by a member 9 within a rectangular metal enclosure. The end of each tubular conductor is compressed to provide a flat surface on each side, and the conductors are connected to further corresponding conductors by straps 15, 16 which are bolted to the flat surfaces. After two conductors are so interconnected, an insulating sleeve 18 which is slightly larger than the insulating tube 8, which covers most of the conductors, is slid forward over tube 8 until it covers the complete joint. Sleeve 18 may be taped to tube 8 with a thermosetting tape which may be cured in place. The rectangular metal enclosure comprises U-shaped sections 12 with L-shaped flanges on their ends to permit fastening of the sections together and panels 13 also of U-shaped cross-section pushed up into sections 12 and bolted into place. To weather-proof the joint between sections a trim strip 19 (Fig. 3A) is applied to cover the flanges in such a manner as to produce a labyrinth-type seal which does not require a gasket to make it waterproof. A thermal barrier comprising a pair of insulating sheets 29 and 30, e.g. glass fibre impregnated with resin, with a polyurethane foam poured between them, is placed in the rectangular metal enclosure at the end to prevent condensation of moisture from the warm interior air in the external sections of the duct. When the enclosure is intended for vertical outside use, certain modifications are made in the flanges (Fig. 4, not shown). Turns in the bus structure are constructed by using angled straps and an elbow of insulating material corresponding to tube 8 (Fig. 5, not shown). Insulating tube 8 and support member 9 are made of glass fibre impregnated with polyester preferably halogenated to make it fire retardant. Member 9 has ridges 10 to increase the path length between the conductors and also aluminium hydroxide is added to the glass fibre so that it has anti-track characteristics.