Bus ducts shall not be arbitrarily stacked or dragged on the ground,and no other work shall be carried out on the shell.Bus ducts shall not be lifted or tied with bare steel wire ropes.Bus ducts should be lifted from multiple points and smoothly shoveled by forklifts without damaging them.Bus ducts should be stored in a dry,clean,and non corrosive gas contaminated warehouse.Flexible packaging spacers should be placed between the upper and lower stacks of bus ducts and properly stored.The direction of the busbar trunking device is provided with a routing diagram and a specific routing list when each batch of busbar trunking is shipped.

　　Bus ducts have corresponding branch lines,section numbers,and are numbered in sequence according to their installation.Before installing the bus duct device,inspect for any damage and check if the bus duct casing is intact.Check for loose bolts on the busbar trunking casing and ensure reliable bolt connections;Check if the bus duct socket is sealed and locked;Measure the insulation resistance with a 500V megohmmeter,and the resistance value should not be less than 20MΩper section.The bus duct should be accurately placed according to the section number,phase sequence,number,direction,and device markings,and the bus duct bracket must be securely installed.When connecting sections,adjacent bus ducts should be aligned,and after connection,the conductors of the bus ducts and the casing should not be subjected to mechanical stress.

　　The major difference in busbar trunking accessories refers to the differential circuit composed of all branch currents except for the bus tie switch and section switch.The small difference of a certain section of busbar refers to the differential circuit composed of all the branches connected to the busbar,including the busbar and section switches,and the current.The large difference ratio differential of the busbar is used to distinguish between faults within and outside the busbar area,while the small difference ratio differential is used for the selection of fault busbars.Usually used in dual mother protection,the large difference is used as the initiating component to distinguish the shortcomings within the area;As a component for selection,distinguish the shortcomings on which bus.

　　The difference between the large and small differential actions in differential protection lies in the small differential action,where the first time limit will trip the busbar switch,and then trip all switches connected to the same busbar as the faulty equipment.The major action is to uniformly trip all switches within a certain time limit,regardless of which bus the equipment is mounted on.Under normal dual mother operation,the input is small and selective.During the process of reversing the busbar,the busbar difference is set to a large difference to avoid the protection misoperation caused by the circulating current when operating the parallel knife switch.The major difference is more of a starting component,and the key is to choose the faulty busbar based on the minor difference,and then take action.