Importance of a Ground Fault Circuit Interrupter – GFCI

In the USA, 200 people die of accidental ground fault electrocution each year. A ground fault occurs when electricity runs where it’s not supposed to – outside the confines of wiring within an appliance, outlet, or tool. If electricity runs through a person, the results can be burns, heart attacks, or even death. A ground fault circuit interrupter (GFCI) is a safety device that’s been used in many homes since the early 1970s.

A GFCI monitors differences in current flowing in and out of an appliance, light, or tool – and most of the time, that’s all it does. Within milliseconds of detecting that electrical current is flowing or leaking where it’s not supposed to (such as through a person or through water), the the GFCI shuts off the electrical circuit to prevent electrocution or electrical fire.

GFCIs are required in new construction where they are installed in interior wet areas like bathrooms, laundry rooms or kitchens, in crawlspaces, garages, and in most exterior applications. In older homes, GFCIs are often retrofitted in wet areas, but are less commonly seen in garages, outbuildings, crawlspaces, unfinished basements, or attics.

It’s a simple step-by-step procedure to replace a defective GFCI, or retrofit an outlet.

  1. Turn off the power to the circuit and for an extra measure of safety, write “DO NOT TOUCH” on a strip of masking tape and place it over the breaker. Install Interior GFCIs Videos
  2. Use a tester to ensure the power to the outlet is actually off (it’s OK to turn off the power to the entire house, just to be sure). Install Exterior GFCIs Videos
  3. Remove the cover plate by removing the screws holding the cover plate on, and pulling the cover plate away from the wall.
  4. Then remove the mounting screw and pull the outlet from the wall.
  5. Next remove the wires from the outlet by turning the fixing screws counterclockwise and removing the wires in this order:   a. Black (hot) b. White (neutral) c. Green (ground)
  6. Strip the neutral and ground wires by straightening them out and carefully stripping the coating away to about ½” from the end. Do not strip the hot wire.
  7. Attach the GFCI, starting with the ground wire. Form a hook on the end of the wire and hook it around the green screw. Tighten the screw clockwise to secure the wire.
  8. You’ll notice that a GFCI receptacle has two holes on the backside (called a “stab-in” receptacle). To attach the neutral wire, push the end of the white (neutral) wire into the hole on the side with a silver screw. Tighten the screw clockwise to secure the wire.
  9. Attach the hot wire: push the black (hot) wire through the hole on the side of the GFCI with a brass-colored screw. Tighten the screw clockwise to secure the wire.
  10. Gently push the wires back into the box.
  11. Line up the mounting screw with the corresponding hole, tighten, and replace the cover plate.
  12. Remove the safety tape from your circuit breaker and turn it on.
  13. Test the GFCI by plugging an appliance (hair dryer, electric razor, etc.) into the receptacle and turning the appliance on. While the appliance is running, press the test button. The appliance should stop immediately. If so, unplug the appliance and press the reset button. Your new GFCI is ready to go! However the most accurate way to test a GFCI is with a tester specifically made to do that.
GFCI chart - use by year