For the electromechanical installation industry, wires and cables occupy an important position in electromechanical installation projects. Copper as its main raw material accounts for 70% to 80% of the total cost of cable products. The price of copper cables increases sharply with the rise in copper prices. , Bringing great difficulties to investors and construction parties in project cost control, for this reason, the research and application of copper-clad aluminum cables are growing rapidly.
Copper-clad aluminum cable refers to a wire and cable that uses aluminum core wire instead of copper as the main body of the cable, and a certain proportion of copper layer on the outside. Copper-clad aluminum cables can be basically divided into two categories according to their uses: one is copper-clad aluminum cables for signal or communication purposes, and the other is copper-clad aluminum cables for power supply. Characteristics of copper-clad aluminum communication cables.
1. Copper clad aluminum communication cable
mechanical properties. The strength and elongation of pure copper conductors are greater than those of copper-clad aluminum conductors, which means that pure copper is better than copper-clad aluminum in terms of mechanical properties. From the perspective of cable design, pure copper conductors have better mechanical strength than copper-clad aluminum conductors, which may not be necessary in practical applications. Copper-clad aluminum conductors are much lighter than pure copper, so copper-clad aluminum cables are lighter in overall weight than pure copper conductor cables, which will bring convenience to cable transportation and cable erection. In addition, copper-clad aluminum is softer than pure copper, and cables produced with copper-clad aluminum conductors are better in flexibility than pure copper cables.
Electrical performance. Because the conductivity of aluminum is worse than that of copper, the DC resistance of copper-clad aluminum conductors is larger than that of pure copper conductors. Whether this has an effect mainly depends on whether the cable will be used for power supply, such as providing power to the amplifier. If it is used for power supply , the copper-clad aluminum conductor will cause additional power consumption, and the voltage will drop more. When the frequency exceeds 5MHz, there is no obvious difference in the AC resistance attenuation under these two different conductors. Of course, this is mainly due to the skin effect of high-frequency current. The higher the frequency, the closer the current flows to the surface of the conductor. The surface of the copper-clad aluminum conductor is actually pure copper material. When the frequency is high enough, the entire current plating Flowed in the copper material. At 5MHz, the current flows in a thickness of about 0.025 mm near the surface, while the copper layer thickness of the copper clad aluminum conductor is about twice as thick. For coaxial cables, because the transmitted signal is above 5MHz, the transmission effect of copper-clad aluminum conductor and pure copper conductor is the same. This can be proved by the attenuation of the actual test cable. Copper-clad aluminum is softer than pure copper conductors, and it is easy to straighten during the production process. Therefore, to a certain extent, it can be said that cables with copper-clad aluminum have better return loss indicators than cables with pure copper conductors.
economy. Copper-clad aluminum conductors are sold by weight, and pure copper conductors are also sold by weight. The price of copper-clad aluminum conductors is more expensive than pure copper conductors of the same weight. But the copper-clad aluminum of the same weight is much longer than the pure copper conductor, and the cable is calculated by length. With the same weight, the copper-clad aluminum wire is 2.5 times the length of the copper wire, and the price is only a few hundred yuan more per ton. In summary, copper-clad aluminum has great advantages. Because the copper-clad aluminum cable is relatively light, the transportation cost and installation cost of the cable will be reduced, which will bring certain convenience to the construction.
