The closed busway (referred to as the busway) is a busbar system composed of a metal plate (steel plate or aluminum plate) as a protective shell, conductive bars, insulating materials and related accessories. It can be made into a plug-in closed busbar with a plug-in junction box at intervals, and can also be made into a feed-type closed busbar without a junction box in the middle. In the power supply system of high-rise buildings, power and lighting lines are often set separately, and the bus duct is installed vertically along the wall in the electrical shaft as the main power supply line one or more times. According to the purpose, a busway is generally composed of the starting busway, the straight-through busway (with jacks and without jacks), L-type vertical (horizontal) bend-through bus, Z-type vertical (horizontal) offset bus, T-type vertical (horizontal) offset bus, T Type vertical (horizontal) three-way bus, X-type vertical (horizontal) four-way bus, variable capacity busway, expansion busway, terminal head, terminal junction box, plug-in box, busway related accessories and fastening devices, etc. . According to the insulation method, the busway can be divided into three types: air type plug-in busway, dense insulation plug-in busway and high-strength plug-in busway. According to its structure and use, it is divided into dense insulation, air insulation, air supplementary insulation, fire resistance, resin insulation and sliding contact busway; according to its shell material, it is divided into steel shell, aluminum alloy shell and steel-aluminum mixed shell busway.
