The quality inspection of busbar trunking can be carried out by examining the appearance of the busbar trunking,checking the color of the surface spray coating,no wrinkles,no flow marks,no bubbles,no penetration,and no scars.There are no scars visible from a distance of one meter in the absence of direct sunlight on the bus duct.Three defects are allowed within a surface area of 1.2 meters,and the screws used to tighten the shell should have anti loosening measures.In addition to allowing blackened gaskets,other fasteners must also be galvanized.The screw should be tightened without slipping,and after tightening,the screw should expose 1 to 2 pitches.

　　Each unit of the bus duct requires a grounding terminal,which is usually made of copper.The equipment is located in an easily accessible center and has a sturdy grounding mark.The cutting surface of the bus duct should be flat and free of burrs,and the distance between the hole and the edge of the bus should be different.The tin lining should be flat,the overlapping surface should be flat,and the insulation packaging paper should not enter the overlapping surface of the busbar.The busbar overlap holes must be concentric and easy to fix.Damaged busbar insulation boards should be replaced and must not be damaged or scattered.

　　Insulation requirements:The insulation resistance between the phase line,shell,and neutral line of each unit bus channel must be greater than 20MΩ.The resistance between two unpainted points on the equipment bus duct should not exceed 0.1Ω.The creepage interval between exposed conductors of different polarities should not be less than the specified value in the table.We check the grounding installation of the plug-in box,and there must be a special grounding bolt in the plug-in box.When the rated current of the output circuit is less than 630A,the grounding bolt should be M8,and the M8 copper nut should be welded to the outer shell of the distribution box.

　　There should be a grounding mark on the grounding terminal,and there should be a grounding wire lead out hole on the outer shell of the box.It is unreliable to use the fixing screw of the equipment bottom plate of the low-voltage circuit breaker as a grounding screw,and it is unreliable to use docking bolts to drill holes in the plug-in box.There should be a PE wiring terminal in the distribution box.The wiring terminals of the plug-in box must be insulated from the housing,and the connecting terminals must not be exposed.After inserting the plug-in box into the bus duct,the pins of the bus duct must not be exposed.Anti reverse plug-in connectors should be installed in the plug-in box and bus duct to prevent power short circuits.Their fixation is completed by mechanical structures and will not affect electrical performance.