"Understanding Your Home" by Building Inspector Mark Visser
Home Page
About Us
Fireplace/Wood Stove
Heating and Cooling
Windows and Doors

CO/ALR Receptacles
Need more information? Use our search box

CO/ALR stands for 'Copper Aluminum Revised' to differentiate these devices from earlier models. Devices marked CO/ALR are specifically designed and approved to
ensure a good connection through the use of a larger contact area and compatible materials
All receptacles connected to aluminum wiring MUST be marked CO/ALR. If your home has aluminum wiring you should check all receptacles by removing the cover plates. The CO/ALR marking can be found on the yoke ( metal part of the receptacle, see picture lower left.) If it is not marked CO/ALR it should be replaced.
Installing CO/ALR receptacles should be done with care. Aluminum is less pliable than copper and small hairline cracks develop if the wire is bent to often. These tiny cracks are effectively reducing the diameter of the wire and this could lead to overheating, which is a fire hazard.
It is best to cut off the old receptacle and strip the wire when installing the new receptacle. An oxide inhibiting compound should be applied to all aluminum and copper connections. When connecting to switches and receptacles, the wire should be formed in a clockwise direction around the screw into three fourths of a complete loop.

WARNING. Because of the specialized knowledge and techniques required for working with aluminum wiring, it is recommended that it be installed only by a qualified electrician.

Back to Top