Aluminum Wires - Dangerous if Not Handled Properly

For a brief period in history, around the late 60’s to early 70’s, aluminum wires were substituted for the copper wires that are common in households today.  When these wires are installed correctly, they are perfectly safe.  However, they are frequently not compatible with modern switches and receptacles.  Here’s what you need to know to keep your home safe:

Identifying Aluminum Wiring:

When replacing a receptacle or a switch, identifying aluminum or copper wire is relatively simple.  Aluminum wire will be a gray color - similar to aluminum foil used in household cooking.  Copper wire is a shiny brown color.  

Precautions to Take with Aluminum Wiring:

When different metals mix in electrical circuits, the mixture of metals can cause oxidation.  This oxidation can make the conductors less effective, and can result in them overheating.  

The way to prevent this risk is to only use receptacles and switches that are specifically rated for the type of connection being made.  

Some wire nuts are rated for aluminum to copper connections (they are typically purple in color).  The packaging on these connectors will state not only the number of wires that they can connect, but also the gauge of wiring that is appropriate for the connector.  These can be used to “pigtail” the aluminum wire.  Pigtailing is when a copper wire is connected to an aluminum wire, then the copper wire is utilized to connect to modern electrical devices.  After pigtailing is complete, the resulting copper wire connection can be utilized just like a normal copper wire.

Also, there are certain duplex receptacles that are rated specifically for aluminum connections.  These are typically marked CO/ALR.  Similar to the wire nuts utilized for aluminum connections, the important piece is to review the packaging for the device being connected to ensure it is appropriate for the connection being made.

Both the purple wire nuts and the CO/ALR duplex outlets are more expensive than a common copper-rated connection, but are well worth the expense.  If the wrong type of connection is used, this could result in an electrical fire!

Have aluminum wiring, and not sure how to handle a replacement of a switch or outlet?  Give us a call!  We’d love to help!