The biggest difference between copper and aluminum wiring is that copper is just a lot more stable of a metal. Aluminum wiring is far cheaper than copper, however, due to some serious issues, it is no longer used in commercial and residential electrical wiring.
When Was Aluminum Wire Used in Homes?
For a period of time in in the 1960’s there was a push to wire homes using aluminum rather than copper. This shift in materials was due to copper shortages that kept the prices out of reach for home wiring. Aluminum was used as a far cheaper wiring replacement in the construction of many track style homes.
In 1973 aluminum wire was found to be dangerous by the U.S. Consumer Product Safety Commission and is not advised for electrical wiring any longer. Because aluminum wiring was still used in homes up to 1973, it still poses danger in the Austin and San Antonio areas.
Aluminum Wiring Issues
The biggest enemy to electricity is heat, as electrical current increases, the hotter the material transferring electricity will get. Although there are many metals suitable to transfer electricity, it is important for the metal to be stable during sustained use.
The biggest issue with aluminum wiring, is that it is less stable when electricity is applied to it. Aluminum is a good conductor of electricity, but over time it will expand and contrast from the heat of electrical current.
Over many years of use, aluminum wire will creep and move in ways that can create loose connections. Over sustained use, the aluminum wire can disconnect from outlets and switches potentially causing a risk of fire through short circuits or arcing.
As both aluminum and copper wiring are exposed to air they will oxidize. Copper oxidizes as you can see when it turns green, but it doesn’t affect the connection of the wire. Whereas when aluminum oxidizes, it creates this crust that builds on it.
The crust that forms on aluminum wiring is not conductive, which can cause issues leading to electrical arcing and heat build up. The crust can sometimes get as much as a quarter inch thick, which poses a serious fire hazard.