To many electrical contractors, copper conductors are seen as superior to aluminum conductors. However, aluminum has been receiving more attention lately as copper prices continue to rise. Is one truly better than the other? The debate is still hotly contested among many in the electrical industry.
The truth is that both copper and aluminum conductors have their distinct advantages and disadvantages. By weighing the pros and cons of each, contractors can make the best decision that will help boost performance and functionality of the specific application.
As one of the oldest known materials, copper has a long history of being used in electrical experiments (including those by Benjamin Franklin and Thomas Doolittle) and was the conductor first used in the telegraph and electric motor.
Superior Electrical and Thermal Conductivity
Other than silver, copper is the most common conductive metal in the world and is seen as the international standard. Aluminum has only 61 percent of the conductivity of copper, which can lead to significantly higher losses in energy in aluminum transformers.
While both copper and aluminum have high thermal conductivity, copper is also superior in this regard. Its greater thermal energy makes it a desired metal for many applications where efficient heat transfer is necessary.
Higher Tensile Strength
In addition, copper’s superior tensile strength allows it to withstand higher pulling forces compared to aluminum conductors. This makes it able to undergo heavy stress while still maintaining its performance. There is still some concern over the use of aluminum in cyclic load applications due to its low tensile strength, which causes many to choose copper instead.
One of the biggest deterrents of copper conductors is that their price fluctuations make choosing copper a gamble for some projects. If the project requires extensive use of wire, the cost can add up quickly. Adding supports to keep heavier copper wire in place can also contribute to the cost.
The greater weight of copper compared to aluminum makes it a poor choice for applications where weight plays a crucial role. This includes over-head high voltage cables that require the light-weight properties of aluminum in order to reduce the danger and cost of infrastructure needed to hold up the wire.
Aluminum conductors have been around since the early 1900s. Despite copper being seen as the superior material, many places, such as Relectric, offer busway systems with both copper and aluminum conductors. This is because aluminum can be the superior choice over copper in certain applications.
Aluminum is less expensive compared to coffer and offers greater cost savings to facilities working with limited budgets. This is because aluminum is the world’s third most abundant material, while copper is the 26th. Because of its abundance, aluminum prices remain relatively stable and are therefore attractive to those with projects that can’t afford to go over budget.
Lighter than Copper
While aluminum may have roughly 60 percent of the conductivity of copper, it also weighs roughly 30 percent less. This quality makes it much easier to install in certain applications. So, if your application doesn’t require the high conductivity of copper, it may be worth looking at aluminum due to its ease of installation and cheaper price. Additionally, labor costs may be reduced when working with materials that are lighter in weight.
Aluminum has less conductivity than copper and can’t be soldered as easily as copper. It would be less advantageous to use aluminum for applications that require high conductivity, such as telecom wiring, motors, and building wires. Aluminum is also less pliable than copper, which can make some installations more difficult and costly.
Not as Reliable
While both copper and aluminum will oxidize when they are exposed to the atmosphere, aluminum has a reputation for being more troublesome when it comes to bolted connections, and it will need greater maintenance over time. While maintenance for both materials is important, it is simply more essential in aluminum connections.
There are pros and cons to aluminum and copper conductors that must be weighed carefully before making a decision. While copper is the more common choice for conductors, aluminum can be a worthy alternative in specific applications. Whether the client wishes to use copper or aluminum, it is important to stress the need for a strong preventative maintenance program to increase the reliability of the system.