Bus duct is suitable for AC three-phase four wire and three-phase five wire systems, with a frequency of 50-60Hz, rated output voltage up to 690V, and rated working current of 250-5000A in power supply and distribution technology systems. As an auxiliary teaching equipment for China's power supply and distribution design system, industrial and mining production enterprises, and high-rise management building equipment, it is particularly suitable for the renovation of factories and old enterprises.

A closed busbar duct is a busbar system composed of metal plates (steel or aluminum plates) as protective shells, wires, insulation materials, and related accessories. The manufacturing process is not limited by the sheet metal, and the shell adopts tile grooves, which increases the mechanical strength of the busbar. The horizontal section of the busbar can produce up to 13m in length.

Fire resistant busbar trunking is an ideal power transmission and distribution equipment for modern enterprises, high-rise buildings, and other places that require high current. It has the characteristics of large transmission capacity, low line loss, high short-circuit strength, and good heat dissipation performance. Its compact structure and good interchangeability make it more convenient and flexible for users to change lines, expand capacity, and branch.

When the busbar is short circuited, the short-circuit fault current generated by normal operation is many times greater than the current flowing through the power supply, causing the current to flow through the busbar to the short-circuit point. This type of short-circuit current often reaches over 15ka, which has an impact on the force (mechanical) and thermal effects of the bus duct. To this end, it is necessary to verify the ability of the bus duct to withstand various short-circuit fault current protection effects, that is, to verify the dynamic stability and thermal stability of the bus duct.

The loss caused by resistance in the current carrying bus duct is converted into heat, resulting in an increase in the temperature of the bus duct. Although copper and aluminum materials themselves can be used at higher temperatures without affecting their mechanical design strength, the working temperature requirements for bolted contact surfaces are higher, making them prone to oxidation and increasing the resistance of the contact surfaces. The increase in contact resistance leads to a continuous rise in contact surface temperature, forming a vicious cycle that causes damage to the student's contact area. Therefore, oxidation of the electrical contact surface becomes the main factor limiting the temperature of the bus duct. The silver plated bolt connection on the connection surface allows for higher bus duct temperatures, but the cost is very high. Generally speaking,

The allowable temperature for busbar trunking is relatively low. The allowable temperature for busbar trunking in China is 85-90 ° C, and the allowable temperature for the enclosure of enclosed busbar trunking is 65-70 ° C. When welding, different temperatures up to 110 ℃ are allowed. Generally speaking, under the short-circuit Joule's law, the design of bus ducts should also take into account the occurrence of accidents. In the event of a short circuit in a power grid enterprise, although the protective control relay can quickly respond and cut off the circuit, the delay time is only a few seconds to a dozen seconds. However, the short-circuit current is extremely large, and the heat generated is also very large, causing a significant increase in the temperature of the bus duct in a short period of time.