From the 1950s to the 1970s, many of the new homes built in Calgary were outfitted with aluminum wiring, which is said to be more than 55 times more likely than copper wiring to cause a fire. Aluminum wire was popular because copper had become much more expensive, and using aluminum was a chance to undercut costs. As aluminum is more conductive than copper, too, it seemed to be a very good choice.
The problems with aluminum wire appear when it is used in branch circuits, or the smaller wires that deliver electricity to plugs, switches, and lighting fixtures from the electrical panel. Although fine as a conductor, aluminum wiring has a tendency to lose contact with connection points, which can cause arcing, melting, and fires. Aluminum wiring has now been banned from use in branch circuits because of this.
If you suspect or know your home was built with aluminum wiring, a licensed electrician like us at A-Star should come and inspect your system to ensure there are no hidden problems. Older wiring systems have been grandfathered in underneath newer codes, so provided there have been no haphazard DUI projects undertaken, your home may not need a complete electrical system overhaul. However, since most home insurance companies will charge an additional premium for aluminum wiring, you will save money in the long run by having the risk mitigated properly.
Why Aluminum Wiring Can Fail
Aluminum deteriorates very quickly … far quicker than copper. It is prone to expand and contract rapidly when it gets hot and cools off, and is much softer, meaning it is susceptible to being broken and damaged with little to no cause. These constant changes can result in loose wires and connections.
It is also not uncommon at all for wiring to rust. The rust on copper is green, and is actually a fairly good conductor itself, so it’s not a big deal when copper wiring rusts. The rust on aluminum wiring is white and not a good conductor, interfering with the flow of electricity and causing overheating.
Sign of a failing aluminum wiring electrical system are:
- Breakers often blowing or tripping
- Sparks when plugging in or turning on an electrical appliance
- Heat coming from switches and outlets
- Flickering or static in televisions, radios and computers flicker when turned on
- Filament lightbulbs burning out too quickly
- An odor something like burning plastic coming from plugs and switches
Aluminum Wire and Copper Wire Should Not Be Used Together
Over the years we have seen many instances where people have made their own repairs to their electrical systems and spliced together new copper wire to older aluminum wire. This is never advisable without the use of a proper splice connector. The wires must be individually connected to prevent what is called galvanic corrosion. That is when one metal (aluminum) corrodes faster than another (copper) when they are joined and an electrical current is passed through them. The increased corrosion of the aluminum wire will reduce contact with the copper wire, resulting in increased risk of overheating.
Problems at Connection Points
- Creep. Aluminum wire expands and contracts when it heats up and cools down. The repetition of this movement causes it to “creep” away from connection points. When aluminum wiring is wrapped around a screw terminal, a switch or a receptacle, this expansion and contraction causes it to “creep” away from the terminal, making for high resistance. This greatly increases the chances of an arc.
- Thermal Expansion. Aluminum heats up and cools faster than copper. So, when aluminum wire is used with copper wire, or against a wire nut, there will be an increase in resistance due to the speed of expansion and contraction and loss of good contact.
- Wire Oxidation. When bare aluminum wire is exposed to the air it will oxidize immediately. At aluminum wire termination points that oxide must be removed promptly and prevented from forming again.
Choose A-Star of Calgary for Your Electrician Needs
We at A-Star Electric are a group of certified journeyman or apprentice electricians who are committed to providing the very best in electrical service for your home or business. We offer electrical panel repairs and replacements, aluminum wiring repairs, wiring upgrades, lighting design and installation, electrical work for renovations and overhead line service. Contact us for more information