How to detect aluminum alloy cable

- May 12, 2018-

With the gradual understanding of aluminum alloy cables by engineering application companies, 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 that engineering application providers must Accurately grasp the basic knowledge.

First, the core compression coefficient

The aluminum alloy cable and the traditional power cable have some differences in the process structure and auxiliary materials. The aluminum alloy cable conductor adopts the aluminum alloy monofilament compression and plying method, and the 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 conductors can be clearly seen (the traditional cable manufacturing process, the core pressure coefficient can only reach about 82%).

Second, flexibility can

Aluminum alloy cable is controlled by ASTM-B800 electrician using 8000 series aluminum alloy wire, adding appropriate amount of copper (Cu), iron (Fe), magnesium (Mg) & hellip;... etc. and rare earth aluminum intermediate alloy material through special synthesis annealing The high-tech new environmentally-friendly and energy-saving power cable developed by the process has superior conductor flexibility. 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, and at the same time, practically to the aluminum alloy cable. Installing applications 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 wrapped like a rope, and the destructive and violently collapsed aluminum alloy monofilament, the experimental conclusion requires at least 18 round trips to produce a crack or The phenomenon of fracture, while the ordinary aluminum core monofilament is generally folded three times out of the crack, five under the absolute must 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 pressing and plying method, conductor section is round core (traditional cable core multi-purpose fan shape), insulation adopts three-color co-extruded cross-linked polyethylene insulation technology, wire core arrangement rules, whole cable round Whole and flexible.

Fourth, the core glossy

Aluminum alloy conductors Due to the optimization of conductor crystal results due to rare earth alloy materials added during smelting process, the cross-section of the core is bright and bright, and the brightness is high. There is a clear sensory difference from the conventional aluminum core cable.

V. Creep performance

The creep performance of the alloy conductor is basically the same as that of the copper core conductor. Through experiments, the copper yield strength is 6.0, the alloy conductor is 54, and the copper conductor is basically the same, which is 300% of the aluminum core conductor.

Six, extension performance

Elongation is an important indicator of the mechanical performance of a conductor. It is an important indicator of the merits of a 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.

Seven, tensile strength

The aluminum alloy conductor is only half 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, even if the cross-sectional area of the aluminum alloy conductor is increased to 150% of the cross-sectional area of the copper conductor under the same electrical performance, The weight of the aluminum alloy conductor is also only 45% of the copper conductor, which makes the aluminum alloy conductor tensile strength 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.

Eight, anti-corrosion properties

The aluminum alloy conductor itself has excellent corrosion resistance, and the good corrosion resistance of the aluminum alloy conductor results from the inherent corrosion resistance of the aluminum material. When the surface of the aluminum alloy conductor comes in contact with air, a dense oxide film with a thickness of about 2 to 4 μm is immediately formed. This layer of oxide film is very dense, especially resistant to various forms of corrosion, and therefore has the characteristics of withstand the harshest of environments, in the actual service life than copper cables extended more than 10 years. (At present, the time for domestic use of alloy cable is not long, it is also 3 to 5 years, so it is impossible to verify the actual service life from the domestic, the Chinese wire and cable network can only refer to the actual use abroad. With regard to the current 40-year use time of Europe and the United States, 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 cutoff, 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 the 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 are achieved. loss.