How to Safely Splice Aluminum Wiring

Splicing aluminum wiring in your home can be dangerous if not done properly. Improper connections can lead to overheating and fires. However, with the right materials and proper technique, you can safely splice aluminum wires. Here is a step-by-step guide on how to splice aluminum wiring safely.

Why Aluminum Wiring is a Concern

Aluminum wiring was used in many homes built between 1965 and 1973. Aluminum is cheaper than copper but it has some drawbacks:

For these reasons, aluminum wiring requires special treatment to splice safely.

Use the Right Materials

To splice aluminum wiring properly, you need:

Do not use regular electrical tape, non-CO/ALR wire nuts, or non-oxygen-free copper. These can cause splice failure.

Step-by-Step Splicing Procedure

Follow these steps carefully when splicing aluminum wiring:

1. Turn Off Power

Turn off power to the circuit at the breaker box. Verify it is off by testing with a voltage tester.

2. Prepare the Wires

Strip back the insulation on each wire by about 1 inch using wire strippers. Aluminum wire is soft so be gentle. Thoroughly clean wires with a wire brush to remove any oxidation.

3. Apply Anti-Oxidant Paste

Apply a thin coat of anti-oxidant paste to each stripped aluminum wire end. This helps prevent future oxidation.

4. Attach Copper Pigtails

Twist a short copper pigtail tightly onto each aluminum wire end. Secure pigtails with a properly sized CO/ALR rated wire nut. Tug gently to ensure a tight connection.

5. Connect Wires

Twist the copper pigtails together with the ends of the other wires in the splice. Secure with a wire nut and ensure a tight connection.

6. Cap with Electrical Tape

As an extra precaution, wrap each wire nut connection with high-quality electrical tape. This helps prevent vibration and loosening over time.

7. Restore Power and Test

Restore power to the circuit at the breaker box. Use a voltage tester and receptacle tester to verify proper function. Check splice area for signs of overheating.

Preventing Future Issues

To avoid problems down the road:

By using the right materials and proper technique, you can safely splice aluminum wiring in your home. However, if you are uncomfortable working with aluminum wiring, contact a qualified electrician. Improper splicing can lead to fires. It's better to be safe than sorry when dealing with aluminum wire.