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 of copper prices. , which brings great difficulties to investors and constructors in project cost control. For this reason, the research and application of copper-clad aluminum cables have grown 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 is covered with a certain proportion of copper layers. 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. In terms of its characteristics, the copper-clad aluminum and pure copper cables are compared as follows.
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 mechanical properties. From the point of view of cable design, pure copper conductors have the advantages of better mechanical strength than copper-clad aluminum conductors, which are not necessarily required in practical application. The copper-clad aluminum conductor is much lighter than pure copper, so the overall weight of the copper-clad aluminum cable is lighter than that of the pure copper conductor cable, which will bring convenience to the transportation of the cable and the construction of the cable. In addition, copper-clad aluminum is softer than pure copper, and cables produced with copper-clad aluminum conductors are better than pure copper cables in terms of flexibility.
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 affects the power mainly depends on whether the cable will be used for power supply, such as power supply for amplifiers, 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, the AC resistance attenuation at this time has no obvious difference 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 reaches a certain level, the entire current is plated. It flows in the copper material. At 5MHz, the current flows in a thickness of about 0.025 mm near the surface, and the copper layer 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 conductors and pure copper conductors 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 in the production process. Therefore, to a certain extent, it can be said that the return loss index of cables using copper-clad aluminum is better than that of cables using pure copper conductors.
economical. Copper-clad aluminum conductors are sold by weight, as are pure copper conductors, and copper-clad aluminum conductors are more expensive than pure copper conductors of the same weight. But the same weight of copper-clad aluminum is much longer than the pure copper conductor, and the cable is calculated by length. The same weight, copper clad aluminum wire is 2.5 times the length of copper wire, the price is only a few hundred yuan per ton. Taken together, copper clad aluminum is very advantageous. 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.