The manufacturing process of enclosed busbar trunking is not limited by sheet metal,and the shell is made into a tile groove form,which increases the mechanical strength of the busbar.The horizontal section of the busbar can be produced up to 13m long.Due to the shell being made into a tile groove form,the pit groove position intentionally separates and fixes the busbars,with a spacing of 18mm between the busbars.The ventilation between the lines is good,which significantly improves the moisture-proof and heat dissipation functions of the enclosed busbar duct,making it more suitable for the southern climate;Due to the gap between the wires,the temperature rise of the wires decreases,which increases the overload capacity and reduces magnetic oscillation noise.

　　Plug in enclosed busbar trunking belongs to the trunk type system,which has the advantages of small volume,compact structure,reliable operation,high transmission current,easy tapping and feeding,convenient maintenance,low energy consumption,and good dynamic and thermal stability.It is widely used in high-rise buildings and should be selected as fire-resistant trunking.However,the stray current and inductance generated by it are much larger than those of enclosed bus ducts,so when comparing with the same specifications,its conductive cross-section must be larger than that of densely insulated bus ducts.We consider the protection level of the slot shell,followed by the influence of the building structure on the shape,installation support form,and span of the trunking.

　　Indoor dedicated workplaces,such as large capacity substations,can use IP30 grade enclosed bus ducts to improve their heat dissipation efficiency;For ordinary indoor work,such as electrical shafts and distribution rooms on floors,to ensure safety,enclosed bus ducts with a rating not lower than IP40 should be selected;For indoor damp places or those with splash proof requirements,in order to ensure their normal operation in the event of splashing,enclosed bus ducts with a rating not lower than IP54 should be selected;For outdoor or special requirements such as anti spray,anti wave,and anti-corrosion places,resin insulated enclosed bus ducts can be used separately;

　　In large-span locations,enclosed bus ducts with reinforced enclosures should be selected;The rated current should be comprehensively considered from the aspects of technical performance,heat dissipation effect,and price.Currently,the market mostly selects aluminum alloy shell low impedance dense insulation enclosed bus ducts with good heat dissipation performance and low energy consumption.The enclosed busbar duct can be made into a plug-in type enclosed busbar with plug-in junction boxes at regular intervals,or a feeding type enclosed busbar 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.