How to Splice Outdoor Lighting Wires

Outdoor wire connections need to be protected from the elements.

Splicing outdoor wires properly reduces the chance of electrical shock and assures a working connection for many years to come. All electrical connections must be made inside a junction box. This is to protect the connection from moisture and prevent people from accidentally touching the wires. Junction boxes have to be accessible for inspection and repair without removing finishing materials. Properly splicing outdoor wires is a simple process once you understand the correct products to use.

Things You'll Need

• Non-contact voltage detector
• Wire cutters
• Wire strippers
• Outdoor junction box
• Wire nuts
• Screwdriver

Instructions

1. Turn the power off to the circuit you are working on at the distribution panel. Confirm the power is off by touching a non-contact voltage detector to the insulative cover of the wire.

2. Cut the wire in the location you wish to make the splice with wire cutters. Strip three-eighths of an inch of insulation off each end of the three wires.

3. Insert the two wire ends through the rubber grommet holes in the side of the junction box, leaving about six inches of wire to work with inside. Insert the wire into which you wish to splice through another grommet hole and leave additional wire to work with as well.

4. Twist together the three black wires with pliers. Install a wire nut on top of the connection. Connect the three green and white wires using the same technique.

5. Push the wires into the junction box and install the cover with the screws provided.

6. Mount the junction box off the ground to a stable object. A wood joist on a deck or against the exterior wall of the building are good locations. Make sure the junction box is not in a location where it can be mechanically damaged.

References

• Dulley: How to Install Outdoor Wiring
• Ask The Electrician: Electrical Junction Box Splice