GB310070A - Improvements in methods of guarding for overhead electric lines - Google Patents

Abstract

310,070. Fennell, W. Dec. 19, 1927. Transmission conductor arrangements. - Overhead lines are connected by a metal bridge to space two lines at points in a span between two supporting posts, or to form a catch guard beneath a higher live wire to catch and earth cr short-circuit it if it breaks, the bridge being connected to one line directly and to the other through an insulator so that the two lines may in all cases be used to separate conductors. A metal wire or strip B, Fig. 2, may be clamped or bound to one conductor D<1> and may carry at its other end an insulator C which carries a metal part bound to the other conductor D, or which receives and is bound to the conductor D. The metal of the ends of the bridge contacting with the lines is the same as, or electropositive to, the metal of the lines to prevent electrolytic corrosion of the lines. In a single-phase, hightension line, the bridge B may connect two guard wires R, E, Fig. 3, beneath the live line L to earth the line L when it falls, only one guard E then being earthed directly and the other wire R serving as the return lead. In 3-phase lines, the wire L is replaced by two or three live wires connected to the phases, the wire R then serving respectively as the earthed third phase or the neutral. Insulated bridges B may space the three live wires in the above arrangement or the four lines L<1> - - L<3>, N, Fig. 5, of a 3-phase, low-tension system. In the arrangement of Fig. 3, low-tension lines may be supported vertically beneath the lines R, E by insulated bridges or high-tension lines may be so supported, the line L being at low-tension.