Due to the complexity of power distribution in modern high-rise buildings and the increasing power supply capacity, there is an increasing demand for the reliability and economy of the distribution backbone network. The requirement is a large transmission capacity that 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 space and low cost. The main forms include enclosed dense bus ducts, prefabricated branch cables, ordinary power cables, etc., which need to be designed according to the nature of the building, power load, installation environment, etc.

The plug-in enclosed dense busbar trunking distribution method has been widely used in high-rise buildings. The types of enclosed dense 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, dense type, composite insulation type, high-strength type, etc. The rated working current is 250A to 5000A. The main structure consists of a steel plate bent shell, conductive copper (aluminum) bars, insulation materials, and related accessories. It uses dedicated plug-in terminals to directly insert into transformers or low-voltage distribution cabinets. Bus ducts with sockets can be inserted into junction boxes or plug-in switch boxes, making it easy to lead branches out to floor distribution boxes. Compared with traditional cable distribution methods, enclosed busbars have the advantages of high transmission current, compact structure, convenient tap and distribution, higher insulation strength and dynamic stability, and long service life. In the high current distribution of high-rise buildings, cables have gradually been replaced by bus ducts and are widely used.

　　When installing dense bus ducts,the following points should be noted:

　　1.The installation quality of enclosed dense bus ducts directly affects their functional use,and their installation needs to follow standard procedures;

　　2.After the busbar is plugged in,it needs to be positioned against the pressure plate.,After tightening,tighten the through bolt;

　　3.The installation and use environment must be clean,and the air must be kept clean and moisture-proof;

　　4.When installing enclosed bus ducts,spring brackets and other fixing methods should be used to increase their flexibility and seismic resistance;

　　Choosing a suitable enclosed dense bus duct for the project site can effectively ensure the electrical safety of high-rise buildings