There are many advantages to enclosed bus ducts,but they are also limited by certain conditions in practical applications,such as the type and distribution of electrical loads,installation space,project investment amount,and so on.Due to construction restrictions,transformers and low-voltage distribution cabinets are not located at the same elevation,and when the capacity of transformers is large,using cables is obviously not sufficient to meet the needs of low-voltage and high current transmission.Generally,architecture majors will design installation spaces(vertical shafts)for enclosed bus ducts,with one or more plug-in switch boxes installed on each floor.The plug-in switch boxes will then send power to various electrical equipment and circuits through cables and wires.

　　In order to ensure electrical safety,attention should be paid to the continuity of the power supply line during design,and a dual circuit form should be considered,with a certain safety interval between the two circuits as much as possible;When selecting the specifications for enclosed bus ducts,the conductor cross-section should be as large as possible to ensure sufficient residual capacity;More plug-in interfaces should be set up,but the operating height and power feeder path should be considered,because too many vertically arranged enclosed bus duct sockets will make the height of the plug-in box on each floor too high,making operation and maintenance inconvenient.

　　Due to the low impedance of enclosed bus duct lines,a model with matching short-circuit breaking capacity should be selected when selecting circuit breakers in plug-in boxes;For enclosed bus ducts installed vertically on shear walls,it is not necessary to provide load data to building designers.Using enclosed bus ducts is a more reasonable choice.Due to the limitations of engineering construction,the high-voltage distribution room and transformer room are located on different floors.The low-voltage side of the two transformers is connected to the low-voltage distribution cabinet using air type bus ducts.Traditional small and medium-sized low-voltage electrical power transmission and distribution methods mainly rely on cables,and also require the use of cable trenches,cable bridges,steel pipes,and other facilities.

　　The current cross-sectional area of the manufactured cable is 500mm,therefore,the current carrying capacity of the cable is 800A.Due to the long length and heavy weight of large section cables,in order to avoid damaging the cable insulation layer,the mechanical force of the middle fixing device should not be too strong when vertically arranged.Therefore,when laying large section cables vertically in high-rise buildings,the problem of overweight slippage and cable section deformation has always been difficult to solve.The enclosed bus duct does not have this problem because it is rigid,so the mechanical fixing method can be made very firm.In addition,the large cross-section of the conductor in the enclosed bus duct can exceed 1000mm,and the double conductor can exceed 2000mm.In addition,the busbar is rectangular with a large surface area,which results in weaker skin effect,larger heat dissipation area,and lower temperature rise.This means that the current carrying capacity of the cable is much higher than that of cables with the same cross-section.