How To Install A Ground Fault Circuit Interrupter

A ground fault circuit interrupter, or GFCI, will shut off power in 1/40 of a second to protect people from shock hazards. For safety, GFCI's are required by code in areas around water,such as kitchens and bathrooms, among other areas in the home.

Often, people with older homes will replace an ungrounded outlet with a GFCI to get that extra measure of safety.

The first step in installing a GFCI receptacle is to make sure that the power is shut off. Plug a normal table lamp into the receptacle, switch it on, and prove that the outlet is working. Find the circuit breaker by watching for the lamp to switch off. Flick it on and off a few times and verify that circuit breaker feeds that outlet.

Make sure that breaker is labeled properly. Switch it off and cover the handle with tape (or a note) to ensure everyone knows you're working with that circuit. Now go back to that outlet to make sure it is off and safe.

1. Remove the face plate and outlet. Once you pull the outlet out, pay close attention to where the different colored wires are connected.

2. Inspect the wiring, looking for frayed wiring or cracked insulation. If you do see a problem, it may be necessary to cut the wire back a little bit and re-strip the wiring.

3. Remove the wiring from the old outlet.

4. Connect the new GFCI. Connect the ground wire first. Examine the back of your new GFCI receptacle. You'll see two sets of terminal screws, with labels indicating "Line" and "Load." A GFCI's incoming power connects to the "Line" terminals - white to the silver screw and black to the copper-colored screw. If you only have one set of wires, connect to the "Line" set of terminal screws.

5. Connect the downline wiring to the "Load" screws. A GFCI is a "Ground Fault Circuit Interrupter." It "trips" quickly on an electrical fault to ground - removing power from the receptacle and switching power OFF to the "Load" terminals in the back. Other receptacles wired downline of this GFCI outlet will be protected by this GFCI and will lose power when a fault is sensed anywhere in the circuit. If the downline outlets are ALSO GFCI receptacles, you'll need to connect all wires to the "Line" terminals - you can't "feed" a ground fault from a ground fault.

6. Dress the wiring into the box, keeping them straight and tight against the back. A GFCI is larger than a standard receptacle, so you'll need the extra room. Mount the GFCI into the box and attach the new faceplate provided with the GFCI.

7. Re-energize the circuit breaker and ensure the GFCI is working correctly. Plug your test lamp into the the GFCI receptacle and make sure that it's working. Press the "Trip" or "Test" button on your GFCI and make sure the lamp goes off. Press the "Reset" button and power should be reestablished.