motherComparison of technical functions between cable trays and cables:

There are many advantages to using bus ducts, which are widely used in low-voltage distribution system transmission mainline projects and are increasingly replacing cables.

The technical functions of bus ducts and cables or pre branch cables are characterized by good heat dissipation, low impedance, and high current carrying capacity. The technical functions of bus ducts with a current carrying capacity of 630A or above are compared with those of cables with a current carrying capacity of 630A or above or pre branch cables. Under the same current carrying capacity, copper materials can be saved by 10-35%, and electrical energy loss can be reduced by more than 15%. The live busbar is fixed and enclosed in a grounded metal casing, and flame-retardant insulation materials are used for phase and ground connections. And then ensured the electrical and mechanical stability. An intelligent monitoring device has been added to the bus duct, making the operation very safe and reliable. By utilizing the plug-in box for branching, it is possible to safely insert and disconnect branches even when the busbar is live. Bus duct has the characteristics of convenient construction, simple protection, horizontal, straight, criss crossing arrangement, neat and beautiful wiring, and standardized safety. Together, it can reduce energy waste and save copper usage. Therefore, bus ducts have been widely used in low-voltage distribution system transmission mainline projects and have increasingly replaced wires and cables. Bus ducts have been widely used in developed countries abroad, as well as in Hong Kong, Macau, and other regions of China. In Guangzhou, Guangdong Province, China, over 90% of the main lines leading from the power distribution rooms of buildings with 12 floors or more to each floor are equipped with bus ducts; 630KVA transformer to the incoming cabinetSelect bus duct. In order to ensure the safety and reliability of power supply and reduce the occurrence of disadvantages, enclosed bus ducts have become the low-voltage distribution system for multi-storey industrial plants, large exhibition centers, hotels, commercial buildings, supermarkets, especially high-end hotels, large commercial buildings, high-rise and super high-rise buildingsProduct.

Bus ducts have the following characteristics compared to cables:

1.1 Bus duct is a flat conductor, which has the characteristics of good heat dissipation, low impedance, and high current carrying capacity compared to circular conductor cables or pre branch cables. Compared with cables or pre branch cables with a current carrying capacity of 630A or above, bus ducts with a current carrying capacity of 630A or above can save 10-35% of copper materials and reduce energy loss by more than 15% under the same current carrying capacity. The bus duct carries a large amount of current on weekdays, which facilitates the connection of feeders and reduces energy consumption together. It is very suitable for AC power supply and can withstand long-term operation at a given voltage value. Under the condition of alternating current within one minute, the bus duct will not be broken down and there will be no flashover. The peak withstand current it can carry will meet the standards.

The service life of busbar trunking is approximately 2-3 times that of cables and branch cables. Hong Kong, Macau, and some European countries have clear regulations that the service life of cables is 12-15 years. In fact, the service life of bus ducts is as long as 30 to 50 years. Bus ducts can be divided into air insulated and fully insulated categories. In general, the inherent structure of bus ducts with air insulation is simple and covered with insulated bus ductsHeat dissipation characteristics and high current level. The electrical shafts and bus ducts installed in high-rise buildings are equipped with a certain socket diameter, and the installation of such joints should consider multiple human disturbances. However, the initial capacity of the bus duct is large, and the structure is compact, which also has advantages in situations with high loads.

1.3 The use of busbar trunking ensures stable current carrying function and avoids unnecessary energy loss. The maximum temperature increment current (i.e. the rated current of the bus duct) that satisfies the standard rules for bus duct standards is very important. This current can control the current carrying function of the bus duct. The rated current of a cable is determined by its cross-sectional area. The calculation load varies, the number of cables in the cable tray varies, and different cable trays are used. The temperature inside the tray changes according to these factors, and the current carrying function of the cables also changes accordingly. So the current carrying capacity of the cable calculated by multiplying the reduction factor by the rated current of the cable is not accurate. The installation method of this sealed cable tray also adds energy loss.

1.4 It can be concluded that the capital is low, and there are copper and aluminum conductor materials for bus ducts. Copper conductor bus ducts are more expensive than copper cables, and the price of copper conductor bus ducts above 630A is similar to the cost of cables; Aluminum conductor bus ducts are 25% to 35% cheaper than copper conductor cables. The higher the current, the lower the cost of bus ducts compared to cables. For this reason, using bus ducts for transmission lines with a current carrying capacity greater than 630A is more economical and reasonable than using cables.

The safety function of the 1.5 bus duct is high and it is not prone to fire accidents. The vast majority of bus ducts produced by manufacturers are fire-resistant (flame-retardant) bus ducts. Assuming that the temperature rise of the bus duct is well controlled, there will never be a fire accident; Assuming that the temperature rise cannot be controlled properly and the bus duct does not easily cause a fire. Because there is experimental evidence to prevent flame propagation in general bus ducts (non fireproof and fire-resistant bus ducts), it is safer than general cables.

1.6 Strong flexibility, briefly introduce branch circuits. The bus duct can reserve various sockets, which can be added, removed or moved at any time. Due to its plug-in nature, the bus duct has strong flexibility and can easily lead out branch circuits. Prefabricated cable branch circuits, as they are all prefabricated cables, do not simply lead out branch circuits, and it is also very difficult to add branch circuits to the same cable.

During the renovation, the cost is relatively low. During the project renovation, the busbar trunking, like other equipment, can be disassembled, adjusted to different locations and orientations at any time, resulting in minimal cost loss. However, assuming the cost of cable renovation is significant, the cost of cost loss is considerable.

1.8 High current carrying capacity, able to meet the requirements of transmission lines.

Differences in circuit branches

Bus ducts should be equipped with suitable plug interfaces that can be smoothly widened; The loop current of the numerical value will exceed 6000A. The pre branch cable is equipped with a pre branch joint, which is convenient for daily maintenance but difficult to widen. The current planned for a single cable has been reduced to 1500A, which is not suitable for larger currents to flow through. In on-site equipment, simply rely on a simple architecture to lift the equipment bus duct, saving equipment time; But the layout method of pre branch cables can be divided into multiple categories, requiring collaboration among multiple people and consuming a lot of time.

Safety and economic characteristics

The bus duct is equipped with a metal shell under a closed structure to resist mechanical impact; Even in the event of a fire, it will not ignite. Its inherent security level is high, and the laid out routes are simple and suitable for independent deployment. Pre branch cables are classified as flexible circuits and will shake and vibrate under wind and load impacts. In addition, using pre branched cables can save 34% of total consumption costs. The bus duct is connected with various piercing interfaces, which can add and reduce complete sets of mobile equipment at any time. itThe active network characteristic is thus highlighted, making it easy to connect with branch lines. Prefabricated cables have a complete structure and are not suitable for connecting such branches; Even if branches are added, the difficulty of subsequent manufacturing will still be relatively high.