There is some debate regarding which material is better for use for busbars—aluminum or copper. Both materials have been used with success, but which is better? Or is one better than the other? Which is best for your project?
Busbars have evolved over the last 50 years. That evolution has allowed the use of busbars to surpass the use of hard-wired power distribution. Recent innovations have led to a shift from the demand for copper applications to aluminum ones. The trend seems to be to move back and forth from aluminum to copper.
There are misconceptions regarding the value of aluminum in busbar manufacturing. However, despite arguments that copper is a better choice, either material meets demand when manufactured to industry and environmental standards and installed correctly.
Let’s compare copper to aluminum so that you can make an informed decision regarding your next busbar application.
Copper
Copper is the most common conductive metal other than silver and is therefore considered the international standard for conductivity. It’s one of the oldest known materials and, as such, has been used in applications where ductility and conductivity were essential requirements. Early experimenters like Benjamin Franklin used copper when conducting experiments with electricity.
In 1913, the International Annealed Copper Standard (IACS) was adopted so the conductivity of other metals could be compared to that of copper. Based on this standard, pure annealed copper has a 100 percent conductivity rating. Since processing technology has changed and improved since the standard was created, today’s commercially pure copper can have a higher IACS conductivity value.
Another benefit to using copper is its tensile strength as well as its thermal expansion and thermal conductivity properties. Copper is resistant to corrosion caused by most organic chemicals. The green patina that can form after being exposed to the atmosphere for long periods of time is a protective surface that doesn’t change how copper
Aluminum
The strength of aluminum varies depending upon the alloying agents used. It can be extremely soft, or it can be a mild steel-like strength. The conductivity of aluminum also depends on the alloy as well as the temper. The conductivity of pure aluminum rates at approximately 62 percent of that of copper.
In the 1960s and 1970s, a specific grade of aluminum was popular for use with household wiring. However, poor workmanship in combination with physical property differences between aluminum and copper caused fire hazards. The industry responded by adjusting aluminum alloys to have properties that are more like those of copper.
Aluminum can be much lighter than copper—up to 70 percent more lightweight. Even if a significantly larger aluminum component is required, the resulting weight will still be less than a copper system of the same conductivity rating. The reduced weight of aluminum helps to save costs in a variety of areas. Aluminum requires fewer supports to secure the busbar; transportation costs for aluminum are reduced, and fewer people are required to install aluminum.
Final Thoughts
The debate between copper and aluminum for use in busbar construction is ongoing. Both metals have attributes that are beneficial to the application. Copper typically has a higher conductivity rating, while aluminum is more lightweight and less costly.
It would seem that either metal is appropriate for use with busbars. The question then becomes which properties are beneficial to the particular project at hand.
Resource : www.kenmode.com