The installation of enclosed bus ducts requires stricter and more standardized details compared to ordinary bus duct installations.Ensure that the enclosed bus duct is located in a closed space with a low failure rate,greatly reducing the operating and maintenance costs of the product.The enclosed plug-in busbar should be assembled according to the design and product technical documents.Before assembly,the insulation resistance of each section should be measured,and the measurement results should meet the design requirements,and records should be kept.Bus duct,fixed distance shall not exceed 2.5m.The height of horizontal laying from the ground should not be less than 2.2m.The end of the bus duct should be enclosed with a cover,and the connection between the shells of each section of the bus duct should be detachable.There should be a grounding wire between the shells,and both ends should be reliably grounded.The connection between the busbar and the equipment adopts soft connection.The busbar fastening bolts should be supplied by the manufacturer and tightened with torque wrenches.

　　When assembling enclosed bus ducts,be careful not to damage them.Nylon ropes should be used for lifting,and the joint should be wrapped properly to prevent debris from falling in.The splicing sequence shall be in accordance with the arrangement diagram and number of the enclosed bus duct.Before fastening,the levelness and perpendicularity shall be adjusted so that the levelness and perpendicularity do not exceed the tolerance,and the total length error does not exceed 10mm.In order to prevent accidents,the insulation resistance shall be measured for each splicing.Each section of the enclosed busbar consists of three parts:the outer shell,the conductor,and the insulator.The outer shell and the conductor are relatively fixed in position through the insulator.In order to achieve good sealing of the enclosed busbar,the contact surface between the insulator base and the aluminum cover plate of the base is tight,and a circular rubber gasket is added between the two contact surfaces.

　　When the length of the enclosed busbar laying exceeds 40m,expansion joints should be installed.Suitable measures should be taken at the expansion joints or settlement joints crossing the building.This requirement should be raised when ordering equipment;The installation of the enclosed busbar plug-in box should be reliably fixed.When installed vertically,the installation height should meet the design requirements.If there are no design requirements,the bottom opening of the plug-in box should be 1.4m;Protective measures should be taken for the vertical installation of enclosed busbars below 1.8m from the ground(excluding electrical dedicated shafts,distribution rooms,motor rooms,technical floors,etc.);When the enclosed busbar passes through firewalls and fire-resistant floor slabs,fire-resistant isolation measures should be taken.Any enclosed or plug-in busbar supports or hangers should be installed accurately,horizontally and vertically,and securely fixed.When installed in rows,they should be arranged neatly and spaced evenly.The fixed bracket bolts should be fixed with flat washers and spring washers,with 2-4 exposed threads.

　　Due to the fact that most of the connections of the enclosed busbar are made through welding(including connections from manufacturing plants),and the outer shell of the enclosed busbar is made of aluminum,which is prone to react with oxygen,a dense and difficult to melt oxide film is formed on its surface,and the specific gravity of the oxide film is also high,making it difficult to float out of the molten pool and form weld slag inclusions;In addition,liquid aluminum can dissolve a large amount of hydrogen gas,while solid aluminum hardly dissolves hydrogen gas.Therefore,when the melted weld metal is rapidly cooled and solidified,hydrogen gas cannot be released in time,and it is easy to accumulate and form pores in the weld seam;Factors such as humid welding environment can also affect the sealing performance of the welding joint.Due to the long enclosed busbar,it is not possible to weld it directly before leaving the factory.It can only be transported in sections to the site for welding and assembly.Bumps and collisions during the journey can cause deformation of the enclosed busbar,making it difficult to fit tightly during installation.