The advantages of using plug-in bus duct are as follows:
1. Bus trunking is convenient for tapping: the so-called plug-in bus trunking is that it uses the plug-in method to tap the power of the main line to the branch line, so the tapping is very convenient.
The disadvantage of prefabricated branch cable is that it needs to be customized to the factory; The branch connection mode adopts the open "C" type hoop. After a long time, can the hoop tightening force be ensured? In addition, the price of each branch head is expensive, so the prefabricated branch cable is still not widely used. Any floor needs to cut off the power supply, the bus duct does not need to be cut off, as long as in the case of no-load, take down the bus duct plug-in box. But it is very dangerous to cut off the branch power supply of the prefabricated branch cable when it is electrified.
2. Strong overload capacity of bus duct: the strong overload capacity of bus duct depends on the high working temperature of its insulating material. The material with working temperature of 105 ℃ is used for the overload of bus duct insulating material. The radiation crosslinking flame retardant winding tape (per) and radiation crosslinking hydrocarbon heat shrinkable tube with working temperature above 140 ℃ have been developed. The insulation materials used in the cable usually work at 95 ℃ and 105 ℃, so the overload capacity of the bus duct is far greater than that of the cable.
3. Bus duct can prevent overload fire: on August 27, 2000, Russia's disaster prone Ostankino TV Tower, the world's second tallest building and Europe's first tallest building, burst into flames. The reason is caused by cable overload; The shutdown of three converters in Baosteel was also caused by cable fire.
The insulation layer and skin of ordinary cable will burn, and the flame-retardant cable will also burn under the flame. It will not burn until the flame leaves. The fire-resistant cable will not burn, but it is expensive. Fire resistant cable is only used for the power supply that is not allowed to power off, such as fire protection.
The bus duct shell is made of steel and will not burn. Even if the insulation material of the copper bar burns, the fire will not escape to the outside of the bus duct.
4. Good heat dissipation performance of bus duct: the insulation material (core wire insulation and skin insulation) of the cable is not only insulation material, but also heat insulation material. Therefore, when the power cable is laid in the bridge, it is allowed to lay two layers at most, and the reason is heat dissipation.
The bus duct uses air conduction to dissipate heat, and the heat is dissipated through the steel shell in close contact, so its heat dissipation performance is better than that of the cable.
5. Convenient maintenance of bus duct: it is almost unnecessary to maintain the bus duct. Routine maintenance is usually to measure the temperature rise of the shell and the core bolt, the joint temperature rise of the incoming box, etc. if the core bolt is of grade 4.8, it needs to be tightened regularly. If the high strength bolt of grade 8.8 is used, it does not need to be firm regularly.