Aluminium

The demand for copper has gradually increased the cost of using copper as a commodity. As a result, we’ve seen cheaper alternatives to copper being explored and increasingly used for electrical applications. The leading alternative? Aluminium.

According to the International Annealed Copper Standard (IACS), although aluminium only has 60% of the conductivity of copper it is only 30% of the weight, and therefore significantly cheaper.

So, does this mean we should be choosing aluminium over copper for electrical applications?

Aluminium cable requires a larger cross-sectional area to match the conductivity of the equivalent copper cable. This difference has a knock-on effect on several factors and may be restrictive in certain applications.

As an indication, an aluminium cable needs a 56% larger cross-sectional area to achieve the same conductive capability as a copper cable. The resistivity of aluminium cored cable is about 1.68 times higher than that of copper wire cable.  Aluminium is easy to break after repeated bending, but copper is not. In terms of elasticity index, copper is also about 1.7 to 1.8 times higher than that aluminium.  Copper wire is anti-oxidation and corrosion-resistant, while the aluminium wire is easy to be oxidised and corroded.  Due to the low resistivity, the copper wire cable with the same cross-section is about 30%-50% higher than the allowable current carrying capacity (the maximum current that can pass through) of the aluminium wire cable.

For over 40 years, Electra Cables has been manufacturing cables that are called for under AS/NZS Standards and are rigorously independently tested for ultimate performance. Electra’s Power Cables are Greenstar Certified, with Greenstar Certification being Australia’s only rating system for environmental practices within the building and construction sector.

Electra Cables is one of the largest, if not the largest, stockist of cable in Australasia.