What is Aluminum (AL) Branch Circuit Wiring?
From approximately 1965 - 1975, single-strand (solid) aluminum (AL) wiring was sometimes substituted for copper branch-circuit wiring in residential electrical systems due to the sudden escalating price of copper (CU).
How can I tell if I have AL wiring?
Was your home built in the years 1965-1975? If so, there is a good chance you have AL branch circuit wiring. This includes parts of many neighbourhoods in Calgary, such as Lake Bonavista, Canyon Meadows, Oakridge, and Cedarbrae.
Look at your wiring: In some parts of your home (such as near the electrical panel, or in an unfinished basement) you can see the wiring exposed. On the outer jacket of the wiring, look for writing. If you see writing such as "ALUM, ALOOMEX, or ALUMINUM 12/2" then you do have at least some AL branch circuit wiring.
Main hazards of AL wiring (a few of them):
High coefficient of thermal expansion: AL wiring exhibits a relatively high amount of creep or stress relaxation as compared to copper (CU). This leads to loose connections, which leads to arcing, which can lead to fire.
Oxidization: AL wiring oxidizes readily and the oxide is hard, brittle, and non-conductive. This can lead to failing connections and arcing. By contrast, the oxide that copper produces is still conductive.
Soft metal: Aluminum is a much softer, and less malleable metal than copper. This means that it can be easily squished or broken at connections.
Devices not rated for AL wiring: If you go into a hardware store, most switches or receptacles have copper connections, which are only rated for copper wire and will not safely accept AL wiring.
Repair:
There are 2 options I recommend to my customers with AL (aluminum) wiring.
Option 1) AlumiConn wire repair: This is a method of pigtailing with a cUL approved AlumiConn wire connector that is considered a permanent repair. AlumiConns are much safer and run cooler than AL rated wire nuts, because the CU and AL wiring don’t touch. They are under separate screws within the AlumiConn connector.
Option 2) Replacement: Removing AL wiring and running new copper wiring throughout your home.
Additional protection: Did you know that if a house is built today, current electrical code requires almost all receptacles (there are a few exceptions) in a home to have AFCI (arc fault) protection. These breakers / devices have a computer chip that scans for arcing, and will cut off power to the circuit, if arcing is sensed. As mentioned above, when AL wiring becomes a fire hazard, it's due to arcing. Therefore, adding AFCI protection to older AL branch circuit wiring is an extra layer of protection. I always say it's an "early warning system" for AL wiring.
Decision:
How do I decide what to do?
Question: Are you planning to remove drywall in your home to do any large renovations in the foreseeable future? Did you know that if you are NOT removing drywall, your existing wiring (including all AL wiring) is grandfathered in the electrical code. This means that, since it was code compliant when installed, it is still acceptable. However, as soon as the drywall is opened, you must bring the wiring in that area up to current electrical code. This would require installation of new copper wiring.
DID YOU KNOW?! Generally, AlumiConn wire repair is 1/4 the price of rewiring a home. It’s considered a permanent, safe repair. If I do AlumiConn wire repair to all your AL branch circuit wiring, I will provide a letter, which will be acceptable to most insurance companies. Most of my customers choose this option.
My name’s Jeff Barron. I’m a licensed, insured, and bonded master electrician. My company is Barron Electric. Feel free to check out my website at www.barronelectric.ca
Text / call / email me at (403) 818-6256 or barronelectric@shaw.ca
