


Closed bus duct for power distribution in high-rise buildings
Can withstand large short-circuit loads; Low voltage drop and power loss; Safe power supply, reliable insulation, and good fire resistance; High flexibility and good earthquake resistance; Easy branching and convenient construction and maintenance; Small footprint and low cost. The main forms include: plug-in bus duct, prefabricated branch cable, ordinary power cable, etc. When designing, it is necessary to determine the form of the distribution main line based on the nature of the building, electrical load, installation environment, etc.
The plug-in enclosed busbar trunking distribution method has been widely used in high-rise buildings. The types of enclosed bus ducts can be divided into three-phase three wire system, three-phase four wire system, three-phase five wire system, etc. According to the insulation method, it can be divided into air insulation type, reinforced type, composite insulation type, high-strength type, etc. The rated working current range is from 250A to 5000A. The main structure consists of a shell made of steel plate, conductive copper (aluminum) bars, insulation materials, and related accessories. Directly inserted into transformers or low-voltage distribution cabinets, with plug-in terminals and sockets, the bus duct can be inserted into junction boxes or plug-in switch boxes, making it easy to lead branches out of the floor distribution box. Compared with traditional cable distribution methods, enclosed busbars have advantages such as high transmission current, compact structure, easy tap distribution, high dielectric strength and dynamic stability performance, and long service life. It has been replaced in the high current distribution of high-rise buildings. Cables are widely used.
But it also has some drawbacks, mainly:
The installation quality of enclosed bus ducts directly affects their functionality, with multiple installation steps, high requirements, and long construction periods;
After inserting the busbar, it is necessary to position it with a pressure plate, tighten the through-hole bolts after tightening. Too many branch joints result in multiple fault points;
The environmental requirements for installation and use are high, and the air must be kept clean. However, the ability to prevent moisture and corrosion is poor;
When installing enclosed bus ducts, fixed methods such as spring support are used to increase their flexibility and seismic resistance, making the structure complex;
The comprehensive unit price is relatively high;
The solution of three-phase five wire system is not satisfactory because the PE wire must have reliable grounding continuity and excessive connectors are not allowed, which is impossible for bus ducts.

Yunnan Youtong Electric Co., Ltd. is a professional manufacturer of bus ducts and cable trays, with high cost-effectiveness. Crafted with ingenuity, it is durable, with complete specifications and low prices. If you need it, please feel free to call us for consultation!





























