Aluminum wiring became a popular option for homes built in the 1960s and 1970s due to the high cost of copper at the time. However, aluminum wiring has been linked to certain risks that homeowners should understand before using it. This guide will cover everything you need to know about aluminum wiring to help you use it safely in your home.
Is Aluminum Wiring Safe?
Aluminum wiring is generally considered safe if it is properly installed and maintained. However, there are some specific risks to be aware of:
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Fire hazard - Aluminum wiring is more prone to loosening, oxidation, and overheating at connections which can lead to fire. Proper installation methods must be used.
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Difficulty with connections - Standard electrical devices like outlets and switches are designed for copper wiring. Special installation procedures must be followed when using aluminum.
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Increased electrical resistance - Aluminum has a higher resistance than copper, which can cause issues like dimming lights. Larger gauge wire is needed.
As long as you use the right safety precautions, aluminum wiring can be used without issues in most homes. Regular inspections and maintenance are critical.
Using the Proper Wire Gauge
One key factor when working with aluminum wiring is using the proper wire gauge or thickness.
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Since aluminum has higher resistance than copper, aluminum wiring needs to be 1-2 gauge sizes larger than copper to carry the same amount of current.
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For standard 15 amp and 20 amp home branch circuits, use 12 AWG aluminum wire in place of 14 AWG copper.
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For larger 30 amp and 50 amp circuits, use 8 AWG aluminum instead of 10 AWG copper.
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Follow all local electrical codes for the correct wire sizes based on your home's electrical load. Undersized wiring can lead to unsafe overheating.
Making Safe and Reliable Connections
You'll need to use special methods when connecting aluminum wires to devices like outlets, switches, and circuit breakers:
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Use CO/ALR rated devices - These are specially designed to securely connect with aluminum wiring using setscrews, clamps, or pressure plates.
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Use copper pigtails - Attaching short 6" copper wires to the aluminum before connecting to devices reduces oxidation and heating issues.
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Properly prepare the wires - Aluminum wires must be thoroughly cleaned and scraped before making connections to remove oxidation.
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Apply antioxidant paste - A special aluminum-copper paste helps prevent oxidization at connections.
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Tighten connections properly - Use a calibrated torque wrench to tighten connections to the proper tightness. Overtightening can damage the wire.
Inspecting and Maintaining Aluminum Wiring
Regular maintenance is essential for aluminum wiring safety:
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Inspect all electrical connections for signs of looseness or overheating annually. Tighten or replace as needed.
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Check wires for damage like cracks or burns that could indicate a faulty connection.
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Periodically remove outlet and switch cover plates to inspect wires. Signs of oxidation or burn marks at connections require repair.
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Electrical arcing or frequent tripped circuit breakers can indicate aluminum wiring issues. Have an electrician inspect.
Taking proper precautions and performing regular maintenance will allow you to use aluminum wiring safely in your home. Consult a qualified electrician if you have any concerns.