07/21/2018
Before we begin this post, I need to explain a few "electrical" terms. These will not be a "by the book" explanation, but a more "layman's terms" that will be easy to understand. If you have any further questions, please do follow up with a qualified licensed electrician.
Service wiring: This is the electrical wiring coming from the pole to the electrical service box in the home. This wire is stranded wire, meaning there are several smaller wires making one larger wire inside the insulation.
Branch wiring: This is the electrical wiring from the service box, to all your electrical outlets and switches. This wire is typically solid wire, meaning it is one strand of wire under the insulation. The reason its solid is because it is easier to manipulated in tight spaces. Think of it as a paper clip and how easy it is to bend how you like it.
During a recent home inspection, I had observed that the home in question had a new electrical service box with Aluminum Service Wiring.
Although this is a pretty standard practice, as aluminum is cheaper, lighter and easier to manipulate than copper, it created a bit of a stir with the clients father, who was adamant that this was a problem.
I will do my best to provide a bit of history, and then provide a bit of education.
First the super quick history.
Between 1965 to 1973, Utility Grade AA-1350 solid aluminum branch wiring was used in place of copper, due to a serious jump in copper prices as copper was being used for the Vietnam war. After a while, homeowners and electricians noticed that the metal was breaking down. The reason it was breaking down was because, at this time, brass was used for war efforts and steel was used in its place to make service connections.
This use of dissimilar metals caused the aluminum to become overheated during certain electrical conditions, and unfortunately had the potential to cause a fire.
Now for the education.
Modern building practices are using a new AA-8000 series aluminum alloy for both the service and the branch wiring (15-20 amps max breakers), as specified by industry standards, such as the National Electrical Code (NEC) for wiring within a building.
AA-8000 series aluminum alloy is installed with materials and methods as specified by the local electrical utility companies. Also, larger aluminum stranded building wire made with the newer AA-8000 series alloy of aluminum is commonly used for electrical services (e.g. service entrance conductors from the utility connection to the service breaker panel) and for larger branch circuits with higher loads such as those for sub-panels, ranges, clothes dryers and air-conditioning units as specified by local electrical building codes.
So what does this mean? It means that it is perfectly safe to have aluminum service wiring in your home as long as it is done in accordance with the local building codes and the National Electrical Code (NEC).
Again, I am not a qualified licensed electrician, and I do encourage you to discuss this issue with one if you have questions.