Aluminum Wiring

Aluminum wiring became a popular alternative for use in homes when the price of copper spiked in the 1960s.  Many homes today still have aluminum wiring that is functioning properly.  Insurance companies may be uncomfortable with it and you should contact yours for their policies. Like many other systems in the home, the key to proper operation is proper installation and maintenance.

When home owners make changes to aluminum wiring and their outlets they often create problems.  Unlike copper which is more forgiving with its connections, aluminum wiring requires more considerations to avoid problems from occurring and there are fixtures and components that are specifically designed for use on Aluminum wired systems.  Here are the main issues:

• Aluminum oxidation When aluminum is exposed to air it undergoes a chemical process called oxidation. Unlike aluminum which is a conductor, aluminum oxide is an electrical insulator which impede the flow of electricity through the oxide layer. To avoid oxidation from occurring, all terminals must be covered with a gray oxidation inhibitor paste.
• Expansion and contraction Aluminum experiences more expansion and contraction with temperature changes compared to copper. Therefore it’s important to provide enough cable length and ensure that connections haven’t loosened.
• Joining aluminum to copper Aluminum and copper are dissimilar metals and when in direct contact may undergo galvanic corrosion. To prevent corrosion from occurring, special CO/ALR connectors and outlets must be used.

It is possible to have an aluminum wired home that is safe for use.  But make sure you have a licensed electrician confirm its proper installation.