A ground fault circuit interrupter (GFCI) is an electrical device that is designed to prevent injury or death from electrical shock by detecting low level ground faults. A ground fault occurs when the current is leaking somewhere. If the current supplied is greater than the current returned for a given circuit the current is going somewhere other than where it should. If this somewhere is the human body, then serious injury or electrocution could occur. Ground faults are often the result of damaged cords, poorly insulated wires, or mishandling of appliances in wet locations. If a GFCI senses minimal current leakage in an electrical device, it assumes a ground fault is taking place and interrupts the power in a fraction of a second to prevent injury.
GFCI’s generally come in two different forms. The most familiar form is the wall receptacle. You know, the funny looking receptacle with the “test” and “reset” buttons on it? The other is a circuit breaker in your main electrical panel. This type of GFCI not only shuts off electricity in the event of a ground fault, but also provides over current protection as any other circuit breaker would. Obviously, with the circuit breaker type, all receptacles on that circuit are ground fault protected. If any of the receptacles in that circuit experience a ground fault, then all receptacles on that circuit will no longer work until the test button is reset at the main electrical panel. Conveniently, the wall receptacle type also protects all receptacles on a given circuit provided the receptacles are downstream of the GFCI receptacle and it is properly wired.
GFCI protection is currently required in kitchens, bathrooms, garages, crawl spaces, unfinished basements, and exterior outlets in new construction and homes that have under gone extensive remodeling. If the receptacle is within six feet of water, then it needs to be GFCI protected. However, because GFCI’s can trip so easily, it is recommended that certain things not be plugged into GFCI outlets, including sump pumps, security cameras, garage door openers, and refrigerators or freezers.
It’s important to regularly test all of your GFCI receptacles; it takes only a few minutes. Don’t just assume because your house is relatively new that they all work. I routinely come across newer homes during home inspections that have non-functioning GFCI’s. Sure, the outlet still works, but the GFCI won’t “trip” when prompted, thus affording zero ground fault protection. For the most part they are reliable, but they do have a shelf life and will eventually need to be replaced. I highly recommend using only licensed electrical contractors for all electrical work. They guarantee their work and have the proper insurance in place in case of accidents. Most homeowner electrical work is not to code and therefore, not safe. It typically stands out like a sore thumb to a home inspector and we will flag it every time.