Aluminum wiring has gotten a bad reputation over the years, but with proper precautions it can be safely installed in your home. Here is a comprehensive guide on how to do it right.
Understanding the Risks of Aluminum Wiring
Aluminum wiring became popular in American homes in the 1960s and 70s because it was less expensive than copper wiring. However, pure aluminum has some properties that make it more dangerous than copper:
- Aluminum expands and contracts more than copper with temperature changes. This can loosen wire connections and cause fires.
- Aluminum has a higher resistance than copper, which means more heat is generated in aluminum wiring at the same amperage. This builds up over time and can deteriorate connections.
- Aluminum oxide, which forms on the surface of the wires, acts as an insulator. This prevents good contact between the wire and connectors, increasing resistance and heat.
For these reasons, aluminum wiring requires special precautions to be used safely.
Choosing the Right Materials
Using the proper materials is essential for safely installing aluminum wiring:
- Aluminum wiring. Only use wiring labeled CO/ALR, which stands for aluminum conductors covered by a jacket of heat-resistant plastic. Do not use old AA-1350 series aluminum wire.
- Switches and outlets. Use devices labeled CO/ALR and rated for use with aluminum wire. Replace any unmarked switches and outlets.
- Connectors. Use connectors labeled COPALUM (also known as purple wire nuts) that are designed and rated for aluminum wiring.
Avoiding galvanic corrosion is also important. Do not mix copper and aluminum wiring or use copper-only rated devices.
Making Safe Connections
Proper technique when making connections is crucial:
- Remove oxidation. Use emery paper or a special brush to remove oxidation from wires before installing connectors. This exposes fresh metal and improves conductivity.
- Apply anti-oxidant paste. Coat the cleaned wire ends with anti-oxidant paste designed for aluminum wiring. This helps prevent future oxidation.
- Twist wires together. Twist aluminum wires tightly together with copperpigtails before installing wire nuts to ensure a tight connection.
- Follow torque specs. Use a calibrated torque screwdriver when tightening connections to ensure proper tightness. Torque specs should be provided with the connectors.
- Check for pitting. Inspect wires for pitting or damage which can prevent good contact. Replace any suspect sections of wire.
Taking these steps helps prevent loose connections and heat buildup.
Inspecting and Maintaining Connections
It is important to periodically check connections to catch any potential problems early.
- Check outlets and switches for warm or discolored plastic, which can indicate loose connections.
- Test outlets and switches with a multimeter or outlet tester to check for faults.
- Inspect the electrical panel for signs of arcing or overheating.
- Retighten wire connectors and connections according to torque specs.
- Have wiring inspected by an electrician periodically, such as when a house is sold.
Proactive inspections allow faults to be found and fixed before a fire hazard develops.
When to Call an Electrician
While a diligent DIYer can safely install aluminum wiring, it's best to have an initial evaluation done by a licensed electrician.
Consider calling an electrician for:
- Evaluating your existing wiring and devices.
- Advising you on proper materials and technique.
- Making connections at the electrical panel.
- Replacing outdated circuit breakers with COPALUM or Arc-Fault models.
- Doing a final inspection and testing connections.
An experienced electrician can ensure the job is done to current safety standards.
Conclusion
While aluminum wiring has risks, it can be safely installed and maintained with proper precautions. Using the right materials, making solid connections, inspecting wiring regularly, and consulting electricians for upgrades and inspections allows homeowners to benefit from aluminum wiring without danger. With increased diligence and preventative maintenance, aluminum can be just as safe as copper.