Bus ducts are like wires and cables,so they are also used as mainline equipment for power transmission.The same 35mm2 wire can be used to carry a rated current of 80A or 125A,but the difference is that the temperature rise of the bus duct for rated currents of 80A and 125A is completely different.An increase in temperature directly reflects an increase in energy loss.The higher the temperature rise,the faster the insulation material ages,and the service life of the bus duct is rapidly shortened.The temperature rise accelerates the aging of nearby insulation materials and equipment,such as wires and cables that are adjacent to or connected to bus ducts,or electrical insulation supports,which can easily cause fire accidents.

　　The temperature inside the bus duct rises and the voltage drop increases.As the temperature rises,the mechanical strength of the bus duct also decreases.After being heated,the stress of metal conductors begins to relax,thereby reducing their mechanical strength;Reduced safety factor,the high temperature of the shell easily burns people.The temperature rise significantly affects the surrounding environment.The same applies to bus ducts.When the maximum temperature rise is 70K and 90K respectively,the current carrying capacity of the same bus duct differs by more than 15%.At present,the temperature rise of bus ducts in the market is 55K,70K,90K,100K,or even above.During the operation of the busbar trunking,it is necessary to continuously check whether there are leaks,water sprays,or hidden moisture sources around the entire system,whether there are any organisms that pose a threat to the system,inspect equipment and accessories,and ensure that the section markings are clear and complete,and the appearance is undamaged and deformed.The insulation resistance of the busbar should be greater than 20MΩ.

　　We need to check whether there are heat sources that affect the temperature rise of the busbar trunking system,verify the number and specifications of the busbar trunking,and inspect the unpacking points of the equipment.This should be done jointly by the installation unit,supervision unit,construction unit,and supply unit,and classified and recorded.Check for any unknown objects entering the interior of the bus duct,inspect for any defects or erosion in the components of the bus duct system,and ensure that the spring elasticity of the bracket is sufficient.If any problems are found,replace them immediately.Then check the equipment and accessories according to the packing list,and ensure that their specifications,quantities,and varieties meet the design requirements.

　　During long-term operation of the bus duct,the joint temperature rise should be checked on schedule once a year,and the joint temperature rise should not exceed 70K according to the specified scale to be qualified.Check if there is any looseness in the connecting bolts and conductor contact parts of all bus duct joints.Prevent the occurrence of overheating in the joint due to increased resistance caused by looseness.Check for aging of insulation materials and melting and deformation of conductive components.If there is a phenomenon of phase to phase grounding or insulation breakdown,it should be dismantled in sections and checked in sections with a voltage tester to identify the fault,or the bus duct should be replaced or insulated again.