How to Add an In-Line Outlet to an Extension Cord

An in-line outlet to extension cord provides convenient access to power sources.

Outdoor activities and home improvement projects often require multiple electrical power tools or accessories. Often a standard four-way receptacle installed on an industrial extension cord makes for the most efficient means to supply power to these out-of-the-way locations with the fewest number of extensions cords required.

Things You'll Need

• Extension cord
• Outdoor outlet box
• Standard receptacle
• Wire cutters
• Regular screwdriver

Instructions

1. Cut off the factory receptacle end of the extension cord even with the plug. Using wire cutters or wire strippers, trim the outside sheath back approximately 4 inches to expose the three-colored conductors within the extension cord.

2. Place a cable grip onto the extension cord with the threaded end of the cord grip facing the direction of the exposed wires. Run the wires through the access hole into the outlet box. Pull the extension cord wire into the outlet box approximately 6 inches to accommodate the connection of the wire to the receptacle to be added later.

3. Screw the cord grip into outlet box and tighten with a pair of channel locks. Tighten the cord grip onto the extension cord until the rubber grommet forms a watertight seal.

4. Strip 1/2 inch of insulation from the black-and-white wire that were exposed earlier. Connect the black wire to the dark, copper-colored wire screw at one end of the receptacle. Connect the white wire to the light-colored wire screw on the opposite side of the receptacle and secure both with a screwdriver.

5. Install the receptacle into the outlet box and secure with screws provided with receptacle with screwdriver. Install the outlet box faceplate onto the outlet box and secure with screws provided with screwdriver. The extension cord is now wired with an in-line receptacle outlet.

Tips & Warnings

• An industrial-grade extension cord with 12-gauge copper wire should be used for extension cords intended for multiple devices simultaneously.

• Outlet boxes rated for outdoor service with weatherproof covers should be the only outlet boxes used for this type of service.

References

• Self Help and More: Switches and Outlets
• Home Addition Plus: Do It Yourself Electrical Wiring Repair and Installation Tips