Part 1: Aluminum vs. Copper Conductors-What’s Best for Your Facility?


Have you considered using aluminum conductors for your plants? As facilities become more expensive to construct and maintain, the necessity of looking to alternative materials becomes increasingly critical to cost-conscious builders. One of these alternative materials, aluminum wire, has drawn much attention lately in the construction industry, especially as copper prices increase and the aluminum market remains steady. Price alone is a compelling argument to consider modern aluminum conductors—at the time of this research, one can expect to spend approximately 3.5 to 5 times more on copper wire than aluminum wire. It's no wonder that more engineers are examining the possibilities and functionality of aluminum wiring.

Since industrial applications are considered one of our primary areas of expertise, we have researched using aluminum conductors as an alternative to copper. We help our clients make informed decisions by sharing the advantages, disadvantages, and valuable data about materials that best meet their facilities' needs.

Today, aluminum conductors are already being used efficiently, and their use is widespread within the construction industry. This wire is currently successfully installed in many industrial applications, such as:

  • Utilities: In utility applications, aluminum has a long-standing track record; it continues to provide substantial performance in commercial and institutional applications.
  • Commercial buildings. Aluminum is also being used more frequently in heavy commercial facilities. MC cable with aluminum feeders is becoming a staple in many high-rise buildings, stadiums, wastewater treatment facilities, and manufacturing facilities.
  • Conductors: Contractors are installing them in service entrance conductors, large conductors, and power distribution conductors.

These various uses demonstrate that choosing aluminum is not a 'novel' concept; instead, it proves to be a useful, high-performing material.

The Benefits of Using Aluminum in Your Facilities

COST SAVINGS

The most obvious advantage in selecting aluminum as a conductor is the savings incurred due to lower material prices. These savings can reach up to 80 percent if aluminum is utilized in every possible way.

Our commodity price comparison study found that the total price of aluminum wiring was 75 to 80 percent less than if the client had chosen to use only copper. Not only is aluminum significantly less expensive than copper, but its market pricing is also much more stable. It should be noted that the price of aluminum is currently rising but only steadily increasing in minimal percentages compared to the market for copper, which fluctuates greatly. There has been a historic rise in copper pricing (a substantial 91 percent increase last year!). This price jump has heightened the urgency and need for solid research on the topic of alternative conductors.

TECHNICAL DESIGN ADVANCES

There are reasons people have shied away from using aluminum in their projects, but those reasons are outdated. Many of the historical "horror" stories associated with aluminum are from technical design problems of the older alloys that now have better product design or higher quality installations. In the past, aluminum may have failed when installers would land small aluminum wire on terminations with different expansion properties that were not listed for the application, such as steel screws in wiring devices. Unfortunately, many people are unaware of these advances to the aluminum design and installations, and the product's negative perception persists.

One crucial product advancement has to do with the physical properties (the chemistry) of aluminum. New alloys have eliminated many of the historical problems. They have better conductivity, creep resistance, strength, and workability than previous aluminum alloys. Also, a property inherent in all aluminum conductors is that they weigh about 50 percent less than copper. This element contributes to more accessible construction installation methods, i.e., bending, pulling cables, training of cables in tight enclosures, etc.

NEC APPROVED

One of the most compelling arguments for using aluminum is that the NEC has approved its use. Section 310.14 states that aluminum conductors "shall be made of an AA-8000 series electrical grade aluminum alloy conductor material." Chapter nine includes several tables showing aluminum conductors' properties, including resistance, temperature rating, ampacities, etc. See the newest edition of the National Electric Code for more details.

Where Can I Use Aluminum?

There are numerous potential applications for aluminum in your facilities. Consider trying aluminum conductors from transformers to switchboards in service entrance applications and installing the conductors from switchboards to motor control centers in feeder applications. The potential of using aluminum conductors from feeders to panel boards is also available, provided space considerations for the panel board terminations are met.

One industry recommendation is to use aluminum wiring at 1/0 or larger since installing smaller conductors tends to become more expensive. This is because terminations in branch circuits necessitate more space, as installation would require both an aluminum-to-copper termination and a copper-to-equipment termination.

You can also use aluminum in medium voltage applications. Most medium voltage applications involve copper wire that is 1/0 and larger, so these cases would be prime targets for substituting copper wire with aluminum. In most instances, utilities provide the medium voltage power distribution in and around a facility and utilize aluminum wire in their design. Aluminum is a common installation material for utilities in underground and overhead line applications.

It's important to mention that the most significant financial savings generally occur where larger cables are used, such as in feeders. Therefore, if you use aluminum, you should do so on larger ampacity runs. Aluminum wire is commercially available in sizes to service 50 amps and above. A standard ampacity limit is 100 amps, but different specifiers are using higher limits. You should also note that branch wire is generally not aluminum.

To learn more about the pros and cons of using aluminum in your construction projects, as well as how to overcome common design and installation challenges, check out the second part of our blog here.

Brent Kooiman, Senior Project Engineer


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