Aluminum alloy overhead cable
Aluminum cable adds alloy elements to electrical aluminum, and at the same time, the mechanical properties of aluminum conductor are greatly improved through process adjustment, so as to avoid the problems of low elongation, poor creep resistance and poor flexibility of pure aluminum conductor, and increase the connection reliability of cable system. In addition, the electrical performance of aluminum alloy is equal to that of electrical aluminum conductor, which is over 61%IACS.
The dc resistance evaluation index of aluminum alloy electric conductor can be referred to the dc resistance value of solid conductor or stranded conductor in GB/ t3956-2008 conductor of cable.
Alloy power cable made up for the inadequacy of previous pure aluminium cable, although there is no improve the conductive properties of the cable, but the bending performance, creep resistance and corrosion resistance are greatly improved, to ensure that the cable for a long time to keep continuous stable performance when overload and overheat, the AA - 8000 series of aluminum alloy conductor, can significantly improve the conductivity of the aluminum alloy cable, high temperature resistance, at the same time solve the pure aluminium conductor electrochemical corrosion, creep, etc.
The conductivity of aluminum alloy is 61.8% of the most commonly used reference material copper IACS, and the carrying capacity is 79% of copper, which is better than the pure aluminum standard. But at the same volume, the actual weight of aluminum is about one-third that of copper. Therefore, the weight of the aluminum cable is about half that of the copper cable at the same load. The use of aluminum alloy cable instead of copper cable can reduce cable weight, reduce installation cost, reduce equipment and cable wear, making installation easier.
The weight of the
On the premise of satisfying the same electrical performance, the weight of aluminum alloy cable is half of that of copper core cable, its section is 1.1~1.25 times of that of traditional copper core cable, and the price is 15~30% lower than that of traditional copper core cable.
Aluminum alloy power cable has good mechanical properties and electric properties, it can be widely used various fields of national economy, such as common people residence, high-rise buildings, elevators, both large supermarket shopping malls, subway, airport, railway stations, hospitals, Banks, office buildings, hotels, postal telecommunications building, exhibition hall, library, museum, ancient buildings, schools, electricity, building, public places of entertainment, tunnels, underground buildings, warehouses, etc., can also be used for metallurgy, steel, coke, coal mines, power plants, power transmission and transformation station, shipbuilding, petroleum, chemical, aerospace, military, medicine, nuclear power plants, paper and other industries, And household appliances, cars, public transport and so on.
The alloy material and annealing process of aluminum conductor reduce the "creep" tendency of the conductor under heat and pressure. Compared with pure aluminum, the creep resistance of aluminum conductor is improved by 300%, and the relaxation problem caused by cold flow or creep is avoided.
Tensile strength and elongation
Compared with pure aluminum conductor, aluminum conductor with special components and special processing technology greatly improves tensile strength and elongation to 30%, so it is safer and more reliable to use.
Coefficient of thermal expansion
The coefficient of thermal expansion is used to calculate the size change of the material when the temperature changes. Aluminum alloys have a similar coefficient of thermal expansion to copper, and aluminum connectors have been used reliably in copper and aluminum conductors for years, and most of the electrical connectors used today are made of aluminum, which is especially suitable for aluminum alloys. So the aluminum conductor is exactly the same as the expansion and contraction of the connector.
Electrical connections made of aluminum are as safe and stable as those made of copper conductors. The composition of aluminum alloy greatly improves its connection performance. When the conductor is annealed, the added iron produces high strength creep resistance performance, which can guarantee the connection stability even in the case of long overload and overheating.
Strong dead weight capacity
Aluminum alloy improves the tensile strength of pure aluminum. Aluminum alloy cable can support the dead weight of 4000 meters long, while copper cable can only support 2,750 meters. This advantage is particularly evident in the wiring of long-span buildings, such as stadiums.
Aluminum's inherent preservative properties arise from the formation of a thin, solid oxide layer when the aluminum surface is in contact with air, which is particularly resistant to all forms of corrosion. The addition of rare earth elements can further improve the corrosion resistance of aluminum alloys, especially electrochemical corrosion. Aluminium's ability to withstand harsh environments has led to its widespread use as a conductor for cables in pallets, as well as many industrial components and containers. The production of corrosion is usually related to the connection of different metals in the humid environment, and corresponding protective measures can be used to prevent the occurrence of corrosion, such as using lubricant, antioxidant and protective coating. Alkaline soils and some types of acidic soils are highly corrosive to aluminum, so aluminum conductors embedded directly should be protected from corrosion by an insulating layer or moulded jacket. In sulfur-containing environments, such as railway tunnels and similar places, aluminum alloys are much better at corrosion resistance than copper.
Aluminum alloy has good bending performance, its unique alloy formulation, processing technology, so that flexibility greatly improved. Aluminum alloy is 30% more flexible and 40% less elastic than copper. Generally, the bending radius of copper cable is 10~20 times of outside diameter, while that of aluminum alloy cable is only 7 times of outside diameter, which makes it easier to connect terminals.
Most commonly used armored cables in China use steel tape armored, with low security level. When exposed to external damage, they have poor resistance, easy to cause breakdown, heavy weight, high installation cost, poor corrosion resistance and short service life. The metal interlock armored cable developed by us standards adopts the aluminum alloy belt interlock armored cable. The interlock structure between the layers ensures that the cable can withstand powerful external damage. Even when the cable is subjected to greater pressure and impact force, the cable is not easy to be broken and the safety performance is improved. At the same time, the armored structure makes the cable isolated from the outside world. Even in the fire, the armored layer improves the flame retardant and fire resistance level of the cable and reduces the risk factor of fire. Compared with steel tape armored, the aluminum alloy belt armored structure is light in weight, convenient in laying, and can be installed without bridge, which can reduce the installation cost by 20%~40%. Different outer sheath layers can be selected according to different places of use, which makes armored cable more widely used.
Single from the bulk conductivity into consideration, aluminum alloy than copper, but we develop conductor is not only made from the aspects of material performance improvement, and also made big breakthrough in the field of technology, we adopt supernormal compression technology, make the compression coefficient is 0.93, and different lines of compression coefficient can reach 0.95, belong to the first in the country. Through the maximum limit of compaction, it can make up for the deficiency of aluminum alloy in volume conductivity, so that the stranded conductor core is as good as the heart conductor, which can obviously reduce the outer diameter of the conductor and improve the conductivity. Under the same load flow, the outer diameter of the conductor is only 10% larger than the copper cable.