GB328656A - Improvements in or relating to electric high tension systems - Google Patents

Abstract

328,656. Condit Electrical Manufacturing Corporation. Dec. 13, 1927, [Convention date]. Divided on 302,273, [Class 38 (v), Electric switches &c.]. Conduits and casings; insulating coverings for cables.-H.T. conductors, such as the main busbars which extend within ducts directly from generators to oil-immersed circuit-breakers controlling the branched feeders are protected from the access of conducting gases, produced during the interruption of heavy currents in the adjacent oil-immersed circuit-breakers, by being. surrounded within the ducts by a body of looselycompacted electrically insulating and fireproof particles, this body thus effectively preventing flashing-over between the conductor and its surrounding metal casing. As shown in Figs. and 2 of the bus-bars 42 are supported on insulators 60, with the metal-castings 54. The space between the bus-bars and the casing is completely filled with a body 80 of insulating material such as quartz sand the upper side of the casing being closed by a cover 58. Openings 62 may be provided in the sides of the casings, to enable branch conductors to be led into similar adjoining sand filled casings. In an alternative form (Fig. 3) the bus-bars 42, 44, 46 of a three-phase circuit are supported on insulating partitions 90, within a common duct 88 which is filled with sand in the manner described. The sand should be of sufficient fineness to prevent corona discharge in the air spaces between the particles and the conductors should be spaced sufficiently from the walls of the duct to prevent flashing over when the ducts are filled with air. In case a leakage point occurs in the duct such as at 82 in Fig. 4, only the sand immediately above this opening will escape while the remainder of the sand remains in position. Specification 302,273, [Class 38 (v), Electric switches &c.], is referred to