According to the purpose, the bus duct is generally composed of starting bus duct, straight bus duct (including Jack and no jack), L-shaped vertical (horizontal) bend bus, Z-shaped vertical (horizontal) offset bus, T-shaped vertical (horizontal) tee bus, X-shaped vertical (horizontal) four-way bus, variable capacity bus duct, expansion bus duct, terminal head, terminal junction box, plug-in box The fastening installation of relevant accessories and bus duct consists of two parts.

According to the insulation mode, it can be divided into air plug-in bus duct, dense insulation plug-in bus duct and high-strength plug-in bus duct.

Air type plug-in bus duct (BMC). Since the joints between busbars are soft connected with copper sheets, the joints are prone to oxidation in humid weather in the south, resulting in poor contact between the joint and the bus and easy heating at the contact, so they are rarely used in the south. Moreover, the volume between joints is too large, the cross-section size of horizontal bus is inconsistent, and the appearance is not beautiful enough.

Dense insulated plug-in bus duct (CMC). Its moisture-proof and heat dissipation effect is poor. In terms of moisture-proof, the bus is prone to moisture and water seepage during construction, resulting in the reduction of interphase insulation resistance. The heat dissipation of passenger cars mainly depends on the shell. Due to the compact layout and installation between lines, the thermal energy of L2 and L3 phases is slow, resulting in the rise of bus duct temperature. Due to the limitation of the shell plate, the dense insulated plug-in bus duct can only produce a horizontal section of no more than 3m. Due to the small air gap between the bus and the bus, when the bus passes through a large current, it will produce strong power, make the magnetic oscillation frequency form a superposition state and produce excessive noise.

High strength enclosed bus duct (CFW). The manufacturing process is not limited by the plate. The shell is made of tile groove, which increases the mechanical strength of the bus. The horizontal section of the passenger car can produce a length of up to 13 meters. As the shell is made of tile groove, the position of the groove is to separate and fix the bus. There is a spacing of 18 mm between busbars. Good ventilation between lines can significantly improve the moisture-proof and heat dissipation functions of bus duct, which is more suitable for the climate in the south. Due to a certain gap between the lines, the temperature rise of the conductor will be reduced, so as to improve the overload capacity and reduce the magnetic oscillation noise. But its stray current and inductive reactance are much larger than that of dense bus duct. Therefore, when compared with the same specification, the cross section of the conductive rod must be greater than that of the densely insulated plug-in bus duct.

Plug in bus duct is a trunk system. It has the advantages of small volume, compact structure, reliable operation, large transmission current, convenient tap feeding, convenient maintenance, low energy consumption and good dynamic and thermal stability. It is widely used in high-rise buildings.