Aluminum alloy cable basic characteristics

[China Aluminum Network] With the gradual understanding of aluminum alloy cables by engineering applications, the aluminum alloy cable market is rapidly developing with rapid development. In practical applications, how to detect and judge aluminum alloy cables, what are the basic performance indicators and The basis is the basic knowledge that the engineering application must accurately grasp.

First, the core compression coefficient:

The aluminum alloy cable and the traditional power cable have certain differences in the process structure and auxiliary materials. The aluminum alloy cable conductor adopts the aluminum alloy single wire compaction and plying method, and its core core compression coefficient reaches 97%, and the conductor is very dense. Compared with traditional copper core cables and aluminum core cables, the difference in conductor cross-section can be clearly seen (the traditional cable manufacturing process, the core core compression coefficient can only reach about 82%).

Second, the flexible aluminum alloy cable is controlled by the ASTM-B800 electrician with 8000 series aluminum alloy wire, and the appropriate amount of copper (Cu), iron (Fe), magnesium (Mg), etc. and rare earth aluminum intermediate alloy materials are added. The high-tech new environmentally-friendly and energy-saving power cable developed by the synthetic annealing process has excellent conductor flexibility, and this superior flexibility can ensure that the safety performance of the aluminum alloy cable reaches or even surpasses that of the copper core cable in practical applications, while giving aluminum alloy cables The actual installation of the cable brings great advantages. In the actual inspection and judgment, the direct hand folding test can obtain that the aluminum alloy conductor is very flexible, can be repeatedly folded or repeatedly wound like a rope, and the destructive and violently folding aluminum alloy monofilament is less than 18 round trips in order to obtain a crack. Or the phenomenon of fracture, while the ordinary aluminum core monofilament is generally folded three times out of the crack, five times to break, an important drawback of ordinary aluminum wire is high brittleness, as long as the installation of a certain angle of twist, the conductor will crack, The cracks will generate heat and corrosion, which is an important cause of fire. This is also the fatal reason why it cannot be used universally.

Third, the cable structure Aluminum alloy cable core adopts tight pressure and plying method, the conductor section is a round core (traditional cable core multi-sector), the insulation uses three-color co-extruded cross-linked polyethylene insulation process, the core arrangement rules, The root cable is round and flexible.

Fourth, the core glossy aluminum alloy conductor due to the addition of rare earth alloy material during the smelting process optimization of conductor crystal results, core section shiny bright, high brightness, and the traditional aluminum core cable has a clear sensory differences 5, creep performance The creep performance of the alloy conductor is basically the same as that of the copper core conductor. Through experiments, it is known that the yield strength of copper is 6.0, the alloy conductor is 54, and the copper conductor is basically the same, which is 300% of the aluminum core conductor.

VI. Extensibility The elongation is an important indicator of the mechanical performance of a conductor. It is an important indicator of the merits of the product and its ability to withstand external forces. It is also an important indicator to test the mechanical properties of cable conductors. After the aluminum alloy cable has been annealed, the elongation rate can reach 30%, while the elongation rate of the copper cable is 30%, and the elongation rate of the common aluminum rod is 15%, which is an important index that can replace the copper cable.

7. The tensile strength of the aluminum alloy conductor is only half that of the copper conductor (113.8:220 MPa). Since the density of the aluminum alloy is only 30.4% of that of the copper conductor, the sectional area of ​​the aluminum alloy conductor is increased to that of the copper conductor on the premise of the same electrical performance. With an area of ​​150%, the weight of the aluminum alloy conductor is only 45% of the copper conductor, which makes the tensile strength of the aluminum alloy conductor has certain advantages over the copper conductor. In the large-span power engineering, due to its specific gravity advantage, its tensile strength advantage is particularly prominent under the equivalent premise. It not only saves a lot of bridges, reduces the labor intensity of installation engineers, but also speeds up the installation process, saves the construction period, and greatly reduces the overall installation cost.

VIII. Anti-corrosion performance The aluminum alloy conductor itself has excellent anti-corrosion performance. The good anti-corrosion performance of the aluminum alloy conductor is derived from the inherent anti-corrosion properties of aluminum. When the surface is in contact with air, a layer of thickness of about 2 to 3 will immediately form. 4μm dense oxide film, this layer of oxide film is very dense, especially resistant to various forms of corrosion, and therefore have to withstand the harsh environment of the characteristics, in the actual service life of copper than the extension of more than 10 years. (At present, the time for domestic use of alloy cables is not long, which is also 3 to 5 years. Therefore, it is impossible to verify the actual service life of domestic cables from domestic sources. Only the actual use of foreign cables can be referred to. The current usage time in Europe and the United States is 40. In terms of the year, his actual service life is more durable than copper.

Nine, electrical performance The resistivity of aluminum alloy is between aluminum and copper, slightly higher than aluminum, but lower than copper, under the premise of the same cut-off, the weight of aluminum alloy conductor of the same length is only half of copper. If the conductivity of copper is calculated as 100%, the conductivity of the alloy conductor is approximately 62.5%, the specific gravity of the alloy is 2.7, and the specific gravity of copper is 8.9, then (8.9/2.7)×(0.612/1)=2, ie 2 The resistance per unit weight of copper is the same as the resistance of one unit mass of alloy. Therefore, when the cross-sectional area of ​​the alloy conductor is 1.5 times that of copper, its electrical performance is the same, ie, the same cut-off, resistance, and voltage as that of copper is achieved. loss.

Gabion Mesh