By application, busbar trunking generally consists of starting busbar trunking, straight-through busbar trunking (with and without sockets), L-shaped vertical (horizontal) bend busbars, Z-shaped vertical (horizontal) offset busbars, T-shaped vertical (horizontal) tee busbars, X-shaped vertical (horizontal) four-way busbars, variable capacity busbar trunking, expansion busbar trunking, terminal end caps, terminal junction boxes, plug-in boxes, related accessories, and fastening devices.
By insulation method, it can be divided into three types: air-insulated plug-in busbar trunking, compact insulated plug-in busbar trunking, and high-strength plug-in busbar trunking. Air-insulated plug-in busbar trunking (BMC): Because the joints between busbars use copper strips for flexible transition, oxidation easily occurs between the joints in the humid southern climate, leading to poor contact between the joints and the busbars, causing the contacts to overheat. Therefore, it is rarely used in the south. Furthermore, the joints are too large, the horizontal busbar sections have inconsistent dimensions, and the appearance is not aesthetically pleasing. Compact insulated plug-in busbar trunking (CMC): Its moisture-proof and heat dissipation effects are relatively poor. Regarding moisture protection, the busbar is easily affected by moisture and water seepage during construction, causing a decrease in phase-to-phase insulation resistance. Heat dissipation of the busbar mainly relies on the outer casing. Due to the tight arrangement of the wires, heat dissipation in phases L2 and L3 is slow, resulting in a higher temperature rise in the busbar trunking. Due to limitations in the outer casing material, densely insulated plug-in busbar trunking can only produce horizontal sections no longer than 3m. Because of the small air gap between busbar phases, when a large current flows through the busbar, a strong electrodynamic force is generated, causing the magnetic oscillation frequencies to overlap, resulting in excessive noise. High-strength enclosed busbar trunking (CFW) is another option. Its manufacturing process is not limited by the material; the outer casing is made in a corrugated pattern, increasing the mechanical strength of the busbar, and horizontal sections can be produced up to 13m in length. Because the outer casing is designed in a grooved pattern, the busbars are intentionally separated and fixed at the groove locations, with an 18mm gap between them. This allows for good ventilation between the lines, significantly improving the busbar trunking's moisture-proof and heat dissipation capabilities, making it more suitable for southern climates. The gaps between the lines also reduce conductor temperature rise, thus increasing overload capacity and reducing magnetic oscillation noise. However, it generates significantly more stray current and inductive reactance than compact busbar trunking; therefore, when comparing the same specifications, its conductor cross-section must be larger than that of compact insulated plug-in busbar trunking. Plug-in busbar trunking belongs to a trunk-type system and has advantages such as small size, compact structure, reliable operation, large current transmission capacity, easy branching and power supply, convenient maintenance, low energy consumption, and good dynamic and thermal stability, making it widely used in high-rise buildings.
