Why is aluminum used as an Overhead Power Cable?

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Which material performs best in overhead power lines? While some questions in the wire and cable industry can lead to heated discussions, the answer for this one is pretty straightforward: aluminum. 

Why is it so? The short explanation is that aluminum is the all-around best material for overhead cables  and utility pole because of its unique properties. With its small density, low price, and high electrical carrying capacity, an aluminum wire is perfect for long-distance lines. Aluminum Bare Transmission cables and Aluminum Overhead Service Drop Cable are two types of wires most frequently used in overhead power lines in the Unites States and many other countries.

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Aluminum vs. Copper in Overhead Power Cables

Copeer and aluminum are two common types of electricity conductors in electrical cables. Power transmission lines span for hundreds of meters between the towers, so overhead cables have to be cost-efficient. Copper wires can be used in overhead wires to a satisfactory outcome. However, aluminum power cables are two times lighter compared to their copper counterparts and six times cheaper while maintaining the same resistance rate. These properties make aluminum the best material for high-voltage transmission lines on the market, as overhead power cable has to be light and flexible in addition to being durable. Aluminum is a malleable material that is less prompt to compression stress compared to copper. This is a clear benefit as overhead cables are subjected to such stress. Utility companies have used aluminum since the beginning of the 20th century. Today, about 13 percent of the aluminum produced is utilized in the energy sector. Aluminum wires have the perfect strength to weight ratio and are cost-efficient because they are not labor-intensive and save construction time.

Aluminum Overhead Power Cables provided by Nassau National Cable

Once the question on the best cable material for the overhead transmission line is settled, a new concern is likely to arrive. What types of aluminum cables are suitable for high-voltage transmission lines? The answer is that there are several variations on the market to choose from. Choosing a particular aluminum wire for power cables is not a difficult process at all as they all are of high quality. At Nassau National Cable, we offer Aluminum Bare Transmission cables and Aluminium Service Drop Cables.

Aluminum Bare Transmission cables are designed to use in primary and secondary power distribution. These cables are placed in overhead distribution channels. The conductors are made of -H19 Aluminum series, which makes the cables soft and easy to install in power distribution lines. ACSR, AAC, and AAAC are the different variations of bare transmission cables depending on the specific standards and approvals that they meet. In ACSR cables, zinc coating is used for corrosion protection, which is a valuable benefit for outdoor use. Once the cable is worn out, it can be used for other purposes due to its recyclability.

Aluminum Overhead Service Drop Cable, another type of wire used in overhead power cables, is also made of a soft -H19 aluminum. The variations include duplex, triplex, and quadruplex conductor cables. A duplex variation is designed for single power lines, while a quadruplex subtype is a three-phase cable. These cables are installed in street lighting for construction sites. Cross-linked polyethylene insulation protects the cable from mechanical influence and chemical impact.

Hint: We know that all metals are good conductors of electricity. Aluminium is a metal. Generally, copper is used in household electrical wires but when it comes to overhead power cables aluminium is preferred because it has better conductivity to weight ratio.

Complete answer:
We know that aluminium is a metal. Metals are generally good conductors of electricity. The conductivity of a metal is the ability to allow electricity to pass through it. Since aluminium is a metal with low resistance and good conductivity it is used in electrical wires. So, option A is correct.
Usually in our household electric wires copper is used. Copper is a good conductor and it conducts electricity better than aluminium. But even when aluminium conducts less well than copper, in the case of overhead power cables aluminium is used because aluminium has comparatively less weight than copper and is also available at a cheap rate. Aluminium wire will be much thicker but it will be lighter compared to copper since the density of aluminium is only one third of that of copper.
The conductivity to weight ratio of aluminium is better than that of copper that is why we prefer aluminium in overhead power connections.

So, answer option D is also correct.

Note:
Remember that aluminium conducts less well when we compare it with copper. But copper is comparatively heavier. The density of aluminium is only one third of the density of copper. So, the light weight of aluminium is the main reason for using aluminium instead of copper in overhead connections.

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