Copper Wire ( Cu )
Copper is the most common conductor metal used for electricity. Cable industry is no different. Copper is not the best neither in conductivity nor in ductility. However, Its' cost efficiency,solderability and durability makes it winner by far against other metals.
Copper is number three in conductivity after gold and silver. Both silver and gold has real high cost in compare to copper. Aluminium has less cost than copper but it is not as good as copper when it comes to electrical conductivity. In addition , Aluminium wire has also durability problems. In some countries Use of aluminium wire and cable is limited by legislations due to durability problem.
Half of the copper mined in the world is used for electricity. One other remarkable benefit of copper is ease of recycling. Copper can be recycled without any loss of quality. Because copper is a ductile metal, it can be drawn to smaller diameters.
Copper wire used in cable production can have different forms. Final cable product can be flexible or rigid. suitable copper wire is used in an accordance.
When called copper wire it refers to round wire in general but there are other shapes of copper wire used in cable productiıon.
Flat : Rarely used. For special applications in the field of electronics and aviation. Also used as concentric conductor in power distribution cables.
Round: The most common form of copper wire used in cable industry. It can be used as solid single wire or different strand compositions. Copper size is measured in metric system around the world with a few exception. American Wire Gauge (AWG) and Standard Wire Gauge two different gauges for copper wire. Below , there two tables for converting awg and swg to metric system.
Sector Shape : Used mostly in power cable production. Purpose of sector shape is to get better proportioned final structure and roundness. By using sector shaped copper wire; isolation, jacket thickness and final diameter of finished cable is reduced.
Resistivity of copper is 1.68x10-8 Ωm. a bit higher than silvers' 1.6x10-8 Ωm and far less than Aluminiums' 2.82x10-8 Ωm. Resistance of a copper wire is calculated with below formula.
Resistance = resistivity(Ωm) x length(m) / cross section area(m2)
Resistivity of special pure oxygen-free copper wire may have up to %1 less resisitivity. Also resistivity of copper wire may vary depending on raw material used.