GFI (or GFCI) stands for Ground Fault (Circuit) Interrupter. National Electric Code currently requires that GFI outlets be used near water sources such as sinks, showers, lavatories, ponds and swimming pools, or where hoses might be in use such as outdoors, garages and balconies. The code has changed many times over the years. For instance you may have GFI outlets in your kitchen but not in your garage.
GFI's protect you from accidents involving electricity and water. Examples are often the stuff of cartoons and urban legends: dropping a hair dryer into the bath you are standing in, changing a light bulb while standing in a puddle near the swimming pool, etc. In our experience, GFI's get tripped most often by 1) unplugging something by holding the cord rather than the cord cap, 2) using appliances such as hair dryers, vacuum cleaners and microwaves which need repair or replacement, 3) by lightning, and 4) by using power strips or extension cords to overload circuits.
You will recognize a GFI outlet by its two tiny buttons which sit between the two receptacles where you plug cords in. (Sometimes the GFI outlet will also have a tiny light. Unfortunately the Code has changed so many times that the light may mean the outlet is working, or it may mean it is not working!) The sure way to tell if the outlet is working is to see if the "reset" button is pushed in.
It is important to know that one GFI outlet with buttons is the "boss" of several other outlets. Sometimes an outlet will not work and you will need to search for its "boss" in order to reset the circuit. A common example is found in early-90's houses with two bathrooms sharing a common wall. Often the reset button in one bathroom controls the outlets in both bathrooms. In newer two-story houses, a balcony outlet may have its "boss" in the garage.
Please note that GFI outlets are not the only kind of GFI protection. Although they are the most common in our area, sometimes even in a new house there are no GFI outlets but there are special GFI circuit breakers in the panel. Either system is code approved.
© Hammack Electric Inc.