GB894781A - Improvements in or relating to electric power distribution systems - Google Patents

Abstract

894,781. Distribution boxes. BRITISH INSULATED CALLENDER'S CABLES Ltd. Sept. 12, 1960 [Sept. 11, 1959], No. 31120/59. Class 38 (1). A distribution system for machine shops and the like comprises a number of busbars having a continuous sheath of insulation, and each bus - bar held in mutually-spaced relationship are supported at intervals along their length by attachment to a longitudinally-extending support by means of a plurality of two-part clamps common to all the bus-bars of the system, one part of the clamp forming part of or carrying a connecting-box. The system shown consists of a number of solid or tubular copper rods 2, each continuously sheathed by insulation 3 and having equidistantly spaced tapped holes 4 along its length for the purpose of making electrical connections. The holes 4 of the several bus-bars are arranged to be in transverse alignment with one another. Where electrical connection to the system is required, the screw-threaded ends of a number of metal pins 30, one for each bus-bar, are screwed into the selected tapping place. The free ends of the pins pass through holes in the lower part 20 of a transverse two-part clamp 19-20 of insulation material used for holding the bus-bars in a mutually spaced relationship to one another, the bottom part 20 of the two part clamp having dependent from it one vertical wall of a connecting-box 16. Each lead from the apparatus or machine to be supplied from the system is either connected directly to the appropriate pin 30 or to the lower terminal 36 of a fusible cut-out 32 attached to the pin 30 by means of the upper terminal socket 34. Channel-section members 40 secured to the dependent vertical wall, by screws 41, form the other three sides of the connecting-box 16. The transverse two-part clamps 19-20 are used to attach the bus-bar system to longitudinal supports 8, either made from highly-conducting metal of angle-, T- or channel-section, or one which has its conductivity augmented by means of a highly conductive longitudinally running tape 26. An earth lead from the consuming point is connected to the longitudinal support 8 directly, or to the conductive tape 26. Where no electrical connection to the bus-bar is required, the tapped holes 4 may be covered by means of a screwed plug 17 of insulating material, or by covering them by a garter or winding of insulation material.