Aluminum Enameled Wire works the same way regular copper wiring works, but there is a significant problem which has made aluminum a thing of the past, when it comes to wiring homes for electricity. The main danger with this wiring is in the connections. When electricity passes through electrical cables and connectors, the wires expand and heat up. One of the issues with this type of wiring is that it expands three times more than copper does. In other words, it has a much higher rate of thermal expansion. When the electricity is turned off, the wires and connections cool down and contract. All the expanding and contracting will eventually open up a gap, exposing the wire to air. The resulting oxidization causes the connection point to get even hotter. Over time, the connection can become loose, creating a fire hazard. See Power Check for more details.

Aluminum wires tend to oxidize and are not compatible with devices designed to be used with copper wiring. If any wiring upgrades or alterations have been done by do-it-yourselfers or unqualified electricians, you could have a problem. The BC Safety Authority has information on the specific requirements of devices to be used with aluminum wiring.

The International Association of Certified Home Inspectors has some great information on aluminum wiring. They state that aluminum possesses certain qualities that, when compared with copper, make it an unfavourable material as an electrical conductor. These qualities will lead to dangerous, loose connections, as mentioned above, with fire hazards becoming more likely. Some of these qualities are:

Higher electrical resistance: Aluminum has a high resistance to electrical current flow. Therefore, given the same amperage, aluminum conductors need to have a larger diameter than copper conductors.

Less ductile: Aluminum will wear and break down more readily when subjected to bending and other forms of abuse than copper, which is more pliable. Wear, over time, causes the wire to break down internally and will progressively resist electrical current, causing a build-up of excessive heat.

Galvanic corrosion: In there is moisture present, aluminum in homes will experience galvanic corrosion when it makes contact with certain dissimilar metals.

Oxidation: The outer surface of the wire will deteriorate when exposed to oxygen. This is known as oxidation. Aluminum wire oxidizes more easily than copper wire, and the compound formed by oxidation – aluminum oxide – is less conductive than copper oxide. Over time, oxidation can deteriorate connections and present an increased fire hazard.

Greater malleability: Aluminum is soft and malleable, so it is extremely sensitive to compression. If a screw is over-tightened on aluminum wiring, for example, the wire will continue to deform or “flow” even after the screw has stopped being tightened. This can create a loose connection and increase electrical resistance in that spot.

Greater thermal expansion and contraction: Aluminum expands and contracts with changes in temperature more than copper does. As time passes, this will cause connections to degrade. Consequently, aluminum wires should never be inserted into the “stab,” “bayonet” or “push-in” type terminations on the back of several light switches and outlets. Aluminum wiring is safer with screw-type connections, that is, where the electrical wire is wrapped around a screw and kept in place by the head of the screw instead of being pushed in through the back.

Excessive vibration: Electrical current causes vibrations when passing through wiring. The vibrating is greater in aluminum than it is in copper, and, over time, can cause connections to loosen.

The enameled cca wire is the color of aluminum and are easily discernible from copper and other metals.