The rated current of the three-phase five wire busbar trunking,PE copper busbar is 400A,and the rated current of the B,C phases and neutral busbar is 800A.A.400A represents the rated current carrying capacity of the copper busbar in the bus duct,and 800A.Bus duct is a bus system composed of metal plates(steel plates or aluminum plates)as protective shells,conductive bars,insulation materials,and related accessories.It can be made into a plug-in type enclosed bus duct with plug-in junction boxes at regular intervals,or a feeding type enclosed bus duct without a junction box in the middle.In the power supply system of high-rise buildings,the power and lighting lines are often set separately,and the bus duct is installed vertically along the wall in the electrical shaft as the main power supply line.

　　Bus ducts can be divided into three types according to insulation methods:air type plug-in bus ducts,dense insulation plug-in bus ducts,and high-strength plug-in bus ducts.Bus ducts are afraid of water and cannot be waterproof.Compared with traditional cables,cables can work normally by soaking in water.Even if ordinary bus ducts are installed indoors,insulation degradation and even short circuits can occur due to building leaks,construction water use,and unconscious splashing of water.Therefore,during bus duct construction,the building structure must be capped,the doors of the distribution room must be locked,and if the bus duct passes through the floor slab,waterproof steps must be taken first.There are no water pipes or fire sprinklers around the bus duct.All of these are necessary measures taken to prevent ordinary bus ducts from being waterproof.As long as the above measures are taken,ordinary bus ducts will not be flooded,and there is no need to make waterproof requirements for the bus duct,just like the distribution cabinet in the substation has never made waterproof requirements.

　　The advantage of bus duct lies in its small size and low energy consumption;Using high conductivity copper bars results in low losses and high transmission efficiency.Because the short-circuit strength of the bus duct is closely related to the structure of the bus duct,the dense bus duct structure will be more compact;High transmission current,easy to tap and feed;The dense busbar trunking has strong heat dissipation capability and adopts double copper bar connection,effectively increasing the contact area of the joint and greatly reducing the temperature rise at the joint location;Easy maintenance:In the later stage,it can be basically maintenance free.Due to the dense bus duct enclosure being made of PE wire,it is safe for people to come into contact with the enclosure;The protection of dense bus ducts is relatively good,which can protect themselves from harm.Long service life.

　　Due to the fact that the bus duct serves as the main line,if a short circuit occurs for some reason,it goes without saying that the entire line will experience a power outage,which is not as good as cables.If the bus duct is short circuited,it is basically caused by quality problems,which requires the manufacturer to strictly control the quality and produce qualified products in order to effectively avoid the occurrence of faults.If a short circuit fault occurs in the busbar trunking system,it can be repaired and put into use,which is more cost-effective and practical than cables.Busbar trunking is expensive,requires a large installation area,has a long installation cycle,and is labor-intensive,resulting in a significant initial investment.