How to Wire a GFCI Outlet

A GFCI outlet, otherwise known as a ground fault circuit interrupter, is the most common type of electrical outlet installed in houses. It is usually housed in a rectangular panel with two separate outlets, each with three holes. The top two holes are slits, and the left slit is longer than the slit on the right. The third hole is located down and to the middle of the top two, and it can either be circular or semicircular. The slit on the left is called "neutral," the slit on the right is called "hot" and the bottom hole is called "ground." Appliances that plug into a GFCI outlet complete the circuit such that current flows from hot, through the appliance, and back to neutral. The purpose of a GFCI outlet is to regulate the electrical current that flows from hot to neutral. If something goes wrong, and there is a change in the current flowing from hot to neutral, a switch in the outlet activates that connects hot to ground, preventing current from being directed through the appliance. The following set of step-by-step instructions will give you all the information you need to wire a GFCI outlet at home.

Step 1: Turn Off Power

Make sure the power to the outlet you're working with is off. Either remove the outlet's fuse, or flip it's corresponding switch in your circuit breaker box. To make sure there is no power going through the outlet, insert both leads of your voltage tester into the slots of the outlet.

Step 2: Access the Wiring

Use your screwdriver to remove the wall plate. Gently pull the outlet out of the wall so that you can get at the wiring behind it.

Step 3: Disconnect Old Wires

Use your needle nose pliers to carefully unwrap the wires from the terminals in the old outlet. There should be four wires connected to the circuit breaker panel, and one coming out of the middle that is grounded. Make sure to keep track of where the wires were connected to the old outlet.

Step 4: Wire the GFCI Outlet

Connect the wires to the new outlet in the same configuration they were on the old one. Go back to your circuit breaker panel and turn the power to the outlet back on, then check it again with your voltage tester to make sure it is working.

Step 5: Finish Up

Turn the power to the outlet back off, and carefully wrap the wires in electrical tape so that they are organized and easy to work with later. Screw the outlet back into the wall, and be careful to press the wires back behind it neatly. Screw the wall plate back on.

The process of wiring a GFCI outlet is fairly quick and simple, but if done wrong there is a significant risk of fire. Make sure you know exactly what you're doing before you decide to work with the electrical outlets in your home.