The bus duct and the casing are tightly attached together,so it can withstand large electrical and thermal stresses,and quickly dissipate the heat generated by the conductive busbar,resulting in a high current carrying capacity.The joint is fastened with insulated bolts and connected with double copper bars,effectively increasing the contact area of the joint and greatly reducing the temperature rise at the joint location.The design of the overall structural strength of the bus duct should not only ensure sufficient electrical clearance and creepage distance with live conductors in the event of faults,but also maintain a safe working state under normal and heavy mechanical loads without deformation due to the effects of electric force and thermal stress.

　　The bus duct socket interface is flexible and convenient to set up,with a large number of sockets and strong universality.When adjusting the position of electrical equipment,there is no need to change the power supply system.The busbar trunking is wrapped with flame-retardant cross-linked polyethylene heat shrink tubing,which has strong insulation performance and does not emit toxic gases when exposed to fire.If the busbar is used for normal mechanical loads,a quality assessment of at least 4 times the length of the unit is required.If it is specified that the busbar is used for heavy mechanical loads.The electrical clearance and creepage distance meet the requirements and will not cause deformation when inserting in and out of the unit.

　　The composite anti-corrosion treatment of cable trays coated with powder or paint after galvanizing should meet the technical quality indicators in terms of galvanized layer thickness,adhesion,and appearance.Cable trays with other anti-corrosion treatments such as galvanized nickel alloy and high passivation should be tested according to regulations and have clear technical quality indicators and testing methods.The tensile and other mechanical properties of the weld seam should not be lower than the mechanical properties of the body material.The surface of the weld seam should be uniform and free of defects such as missed welding,cracks,slag inclusion,burn through,arc craters,etc.It should meet the standards.

　　The temperature rise limit value at the plug-in contact of the movable device on the busbar is not provided with specific data.On the surface of a conductor,heat dissipation is fast,temperature is low,and the rate of valence and electron movement is low.The circuit is flat,which leads to a relatively wide electronic path,resulting in low surface resistance of the conductor and faster electron movement.Unstable connection of connectors,poor contact of joints,and increased electrical resistivity can all cause a temperature rise in the bus duct.When operating under overload,the temperature rises,and the switch at the beginning of the variable capacity cannot ensure overload of the small current after the variable capacity,thus posing a safety hazard.