For mechanical and electrical installation industry, wire and cable in the electrical and mechanical installation works occupy an important position, as its main raw material of copper cable products accounted for 70% of the total cost to 80%,glue gun the price of copper cable with a sharp rise in copper prices growth side of the investors in the engineering and construction cost control extremely difficult to bring about this end, research and application of copper clad aluminum cables rapid growth.
Copper clad aluminum wire refers to the aluminum wire instead of copper wire into the main body, wrapped in a certain proportion of copper wire and cable. Copper clad aluminum cables to points on their use, the basic can be divided into two types: one is the signal or communication cables use copper clad aluminum, and the other is the power cable with copper clad aluminum. On its properties, the copper clad aluminum and copper cables for the following comparison.
First, glue stick the copper clad aluminum communications cable.
Mechanical properties. Copper conductor strength, elongation, than the large copper clad aluminum conductors, which means that the mechanical properties of copper clad aluminum better than copper. From the cable design point of view, copper clad aluminum conductors than copper conductor good mechanical strength advantages, do not necessarily require the actual application process. Copper clad aluminum conductors is much lighter than pure copper, copper clad aluminum cable so the overall weight lighter than the copper conductor cable, so that the cable would transport and erection of cable convenience. Other than pure copper clad aluminum copper soft point, with production of copper clad aluminum conductor cable in terms of flexibility better than copper cables.
Electrical performance. Because aluminum conducts electricity better than copper is poor, making copper clad aluminum conductor DC resistance than the copper conductor large, mainly to see whether the impact of this will be used to power cables, such as providing power to the amplifier, if used for power, then, copper clad aluminum conductors will result in additional power consumption, voltage drop more. When the frequency exceeds 5MHz, the decay time of the AC resistance of conductor at under two different no significant difference. Of course, this is mainly because high-frequency currents, skin effect, the higher the frequency, the closer the flow of current conductor surface, the surface of the copper clad aluminum conductor material fact pure copper, when the frequency is high enough, the entire current plating which flowed in the copper material. In the case of 5MHz, the current near the surface flow of about 0.025 millimeters in thickness, and copper clad aluminum conductor than the thickness of copper layer thickness was about doubled. For coaxial cable, because the transmission signal is 5MHz or more, so copper clad aluminum conductor and copper conductor transmission effect is the same. Attenuation of the cable in the actual test to prove this point. Soft copper clad aluminum conductor than copper, in the production process easier straightening treatment, it can be said to some extent, the cable with copper clad aluminum conductor than copper cable with indicators of a good return loss.
Economy. Copper clad aluminum conductor is sold by weight, copper conductor is sold by weight, the price of copper clad aluminum conductor of the same weight than the more expensive copper conductor. But the same weight of copper clad aluminum much longer than the length of copper conductor, while 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 dollars more per ton. General down, copper clad aluminum on the very edge. Copper clad aluminum cable as lighter, cable transportation costs, installation costs will be reduced erection, construction will bring some convenience.
Second, copper clad aluminum power cable.
DC resistivity. Resistivity of copper clad aluminum wire copper lines than large, pure copper wire is about 1.5 times the value in the same shade of copper clad aluminum wire copper wire weighing about 1 / 2. Calculated according to the skin effect, more than high frequencies in the 5MHz, and compared to the same section of the copper conductor, its resistivity is equal. 50Hz frequency of the power cable in use in the copper conductor skin effect and proximity effect on the 150mm2 gradually become more prominent, and because of the continuous development of science and technology to produce high harmonic currents and energy will be injected into the power supply system in the impedance of the system to generate the corresponding high-frequency harmonic voltage, resulting in voltage waveform distortion and increase power system losses, increase the heat conductor; In addition, the cable so that harmonic amplification, have been in the joints voltage damage to the cable head. Copper clad aluminum conductors will play with high harmonics produced by lower impedance (resistance) effect. Used in other occasions, through the adoption of improved copper clad aluminum wire in a single volume and the corresponding copper process measures, so that the copper clad aluminum / copper composite conductor with the size of the existing ceiling of the outside diameter of the conductor, the DC resistance of conductors to meet the requirements.