How to Splice Electrical Wire

Wire splicing is an essential part of installing lights, switches and receptacles in your home. "Splicing" electrical wire means joining the bare ends of two or more separate pieces of wire by overlapping and securing them together. Wires properly spliced will not separate easily and will be well-insulated to prevent short circuits or electrical shocks. With very few exceptions, your local electrical code only allows wire splices inside a code-approved enclosed box such as a receptacle, switch or junction box.

Difficulty: Easy

Instructions

Things You'll Need:

• Wire stripper/cutter
• Broad-nosed pliers
• Insulated wire connectors

1. Pull the wires together that you want to splice, then cut them the same length. Make sure the wires are straight and not tangled with other wires.

2. Use your wire strippers to remove 5/8 inch to 3/4 inch of insulation from each wire. If your wire stripper isn't clearly labeled with wire sizes, use the hole which is just small enough to cut into the insulation, without cutting the wire underneath. Close the cutter over the wire, turn the cutter to cut the insulation, then pull the cut insulation off the end of the wire.

3. Hold the wires parallel with the ends evenly lined up. Clamp your pliers over the ends and twist the wires together clockwise with four to five turns. Each wire should spiral around the other(s).

4. Twist a wire connector onto the spiraled wires until you feel resistance. If the wires are completely seated and you don't feel much resistance when turning, use a smaller connector. If the connector does not completely cover the bare wires, use a larger connector or remove the connector and cut off enough wire from the splice so that the connector completely covers the bare wires.

Tips & Warnings

• Use split-bolt connectors if splicing aluminum to copper wire. After splicing, insulate the metal connector by wrapping three layers of electrical tape around it.

References

• Wiring a House; Rex Cauldwell; 2002