Busbar trunking is a busbar system composed of metal plates as protective shells,conductive bars,insulation materials,and related accessories.It can be made into plug-in enclosed busbars with plug-in junction boxes at regular intervals,or into feeding enclosed busbars without junction boxes in the middle.The heat source affected by the temperature rise of the bus duct system is the cone screw strip mixer.The cone screw strip mixer is checked for foreign objects entering the interior of the bus duct,and the components of the bus duct system are checked for defects,rust,and whether the bracket springs have appropriate elasticity.If any problems are found,they should be replaced immediately.

　　Bus duct is divided into main unit,feeding unit,tap unit,variable diameter unit,expansion unit,various bending units,etc.The mainline unit is divided into mainline units without tapping devices and mainline units with tapping devices.Two types of mainline units with the same current level have the same basic structure and external dimensions,making it very convenient to connect and install them together.The incoming unit is matched with the incoming box to form the connection component between the bus duct and the cable.The incoming unit can be directly connected to the distribution cabinet or transformer as the power input or output terminal of the bus duct.

　　The feeding unit includes incoming units,incoming boxes,intermediate incoming boxes,and other units.The tapping unit adopts a plug-in junction box,which leads out the power branch from the main line.The tapping current of the junction box is determined by the circuit breaker.The variable diameter unit is used to connect the transition section of two different rated current busbar main units.The standard length of the variable diameter unit is 1 meter,and it can be changed from any current level of 60~5000A to another current level.There are four types of bending units:L-shaped,T-shaped,Z-shaped,and cross shaped,which are used for connecting horizontal and vertical distribution bus ducts and changing the direction of the bus.

　　Copper conductors for bus ducts should be made of purple copper because the purity of copper is generally not high and the resistance cannot meet the requirements of conductivity.Therefore,purple copper needs to be used,and the higher the content,the better.With the intensification of market competition,some manufacturers use high-purity brass as a substitute for good quality to reduce costs.Such bus ducts have poor electrical performance and are prone to high temperature rise,short circuits,and even accident losses during use.Copper bars or aluminum alloy bars are generally used as conductors for bus ducts.To prevent oxidation on the surface of the bus bar,tin plating or silver plating is applied to the surface of the bus bar.