ELECTRICAL DISTRIBUTION SYSTEM HAVING SPECIALLY FORMED AND INSULATED BUS BARS

An electrical distribution system having specially formed and insulated bus bars (40) in back to back, stacked relationship with each other along the length of the busway and spaced apart where tap-off or other connection may be made (34). The bus bars are formed to be interchangeable, to the extent possible, within a busway section (32). For example, in a four bar plug-in section, the two inner bus bars are identically formed and interchangeable by rotating the bars 180. Similarly, the two outer bus bars are also identically formed and interchangeable. The electrical insulation between bus bars is provided by the use of insulating tubes comprising one layer of varnished glass cloth between two layers of polyethylene therephthalate. Each bar (40) is provided with a hump (54) located for tap-off connection along the length of the busway. The insulating tubes are spaced apart from each other on each bus bar (40) to provide a tap-off contact surface (238) on each hump (54). Each tube is provided with notched out segments (236) which overlie the edge of the bus bar (40) at a transition portion of the hump (54). A hump insulator (240) is placed longitudinally along the length of the bus bar (40) on the top and bottom of the hump (54) between opposing plug-in bases and hump edge insulators (242) are placed on the edges of the plug-in bars in overlying relationship with the respective notched out segments (236) on the tubes.