Aluminum Wiring in 1970's homes - Info and Solutions
I've inspected quite a few homes in the Lower Mainland built in the 1970's. It's not uncommon for me to find aluminum wiring. And it's also not uncommon for me to find a portion of that wiring updated incorrectly, where dissimilar metals are connected, which can be a fire hazard.
There are two ways of solving this problem if your home is currently wired this way, or you are considering purchasing a home and this crops up in your inspection report.
Over the past years it's been more difficult to find the receptables that work for aluminum. In fact, a phone call to my local electrical supply company delivered some sad results. No receptacle or outlets that were CU-ALR were available.
According to the British Columbia Safety Authority, it is estimated that there are over 450,000 homes in Canada that are wired with aluminum wiring with no greater problems if everything is properly rated.
You may find that a mixture of aluminum and copper wiring is installed in your home. If your home has aluminum wiring and you need to replace a switch or wall receptacle, the replacement device recommended to install has been of a type that is specifically approved for use with aluminum wiring. In a brochure (as the pdf available from BC Safety Authority) The CO-ALR plugs and switches can no longer be found. At this point pigtailing is the only option for retro-fitting light fixtures and receptables.
"Pigtailing" is a term used to connect copper tails to working aluminum connections. Typical locations for pigtailing would be at light switches and receptacles for example. In order to connect copper pigtails to aluminum, a special AlumiConn connector is used. As far as I'm concerned the only way to pigtail is using the AlumiConn connector bringing copper wire to your receptacle or switch.
Signs of Possible Concern
If you notice any of the following conditions in your home, the causes should be investigated:
- warm faceplates on switches or receptacles;
- strange or distinctive odours in the vicinity of receptacles or switches;
- persistent but intermittent flickering of lights that can't be traced to appliances or other external causes
- unusual static on radio or television.
Because of the specialized knowledge and techniques required for working with aluminum wiring, it is recommended that any retro-fitting be done by a qualified electrician querying him if he is aware of the Alumiconn connections. Settle for no less.
You can find the Alumiconn online if local suppliers don't have them readily available.