The fire-resistant bus duct is used for the power supply of fire-fighting equipment and cannot be used for other purposes.Therefore,this type of busbar has good heat resistance and insulation,and the thermal energy of the busbar slot cannot be dissipated,so it cannot be used at full load for a long time.Except for fire-resistant bus ducts,other buses cannot operate at full load for a long time.The shell and insulation layer of the fire-resistant bus duct are made of fire-resistant materials with a high temperature resistance of≥1100℃and insulation materials with a high temperature resistance of≥300℃.The product has a fire-resistant time of 60 minutes,90 minutes,120 minutes,and 180 minutes.It will only burn when the temperature reaches a high temperature of 920-1050℃,and can operate at full load for more than 8 hours.Fireproof busbar trunking,ordinary busbar trunking or busbar trunking with fire-resistant smoke spreading outer shell and fire-resistant partition,some outer shells are coated with fire-resistant coating,which can transmit heat energy to the interior within the specified time of fire.The busbar trunking can operate normally,with a fire combustion temperature of about 800 degrees,and a fire resistance time of 30 minutes,40 minutes,and 60 minutes,respectively.

　　Starting from the mid-1980s,the intensive type,represented by Zunyi Changzheng Electrical Control Equipment Factory,covered the conductive busbar with insulating material and then fastened it to both sides.Insulation material:polytetrafluoroethylene tape,working temperature of 200 degrees,disadvantage:high temperature decomposition produces lethal toxic gases(octafluoroisobutylene and fluorophosgene),polyvinyl chloride heat shrink tubing,with significant quality differences.Some manufacturers use inexpensive products,but the insulation tested does not reach Class B.Radiation cross-linked flame-retardant tape(PER)has good performance,with a working temperature of 150 degrees Celsius,good waterproof performance,elasticity,and tight wrapping.A special form of busbar that emerged in the evolution of second-generation busbars is the dense busbar air type socket.Due to changes in technology,it has basically become a dense busbar socket,that is,an overall dense busbar trunking.

　　In addition to the insulation layer of the conductive busbar itself,there is also a certain amount of air insulation between the phase lines in the bus duct.Sulfurization insulation technology is used in various elbows.The straight section adopts MT-7-3 rubber sleeve.Sulfurization insulation technology:The material is CZ260 fast curing insulation powder,which adopts quaternary cross-linking curing,and there is no gap between the insulation layer and the conductive row.Its heat dissipation performance,moisture resistance,and insulation reliability are all excellent.However,due to higher costs compared to second-generation busbars,it was not widely promoted.Busbar welding is used for L-shaped(flat bend)and T-shaped busbars,but there is no relevant national standard yet.It is said that welding seam inspection is being considered.The advantages and disadvantages compared to cables are simply the difference between tree trunk power supply and radial power supply.

　　Insulation support is a component of busbar trunking equipment,used to support conductors in busbar trunking equipment.The installation board is used to support various components and is suitable for installation in complete sets of equipment.A frame used to support various components and suitable for installation in a complete set of equipment.The casing is a component that protects equipment from certain external factors and prevents direct access in all directions,with a protection level of at least IP30.A door is a hinged or sliding cover.The cover plate is the upper and lower shell surface of the outer shell,usually referring to a component on the bus duct equipment,used to cover the opening on the outer shell.Fix it with screws or similar methods,and generally do not disassemble the equipment after it is put into operation.