GFCI - ground fault circuit interrupter
by Garet Dennis
GFCI stands for ground fault circuit interrupter. It's a long fancy name for a special type of electrical device designed to shut off the circuit if it senses you getting a shock. They are most often built into receptacles (outlets) but are also built into some circuit breakers and can be found in some consumer products, such as the plug for a hair dryer. GFCI receptacles are easy to recognize: they have buttons marked TEST and RESET (usually black and red). Their design is much more sensitive than a circuit breaker (they trip at only .006 amps) and they shut off power much more rapidly (1/40th second). Modern standards require GFCIs at pools, spas, bathrooms, kitchens, garages, crawl spaces, and exteriors - basically any place that people, water and electricity can get together. They are not intended to protect appliances or wiring; they are to protect YOU!
The U.S. Consumer Product Safety Commission (CPSC) estimates that the rate of death by household electrocution would be cut in half if all homes were equipped with GFCI outlets. GFCIs cost around $10 or $15 each, and an electrician can install them in a matter of minutes.
GFCIs need to be tested occasionally to make sure that they are working properly. Simply push the "TEST" button. The "RESET" button should pop out and anything plugged into the outlet should turn off. Go ahead and check it with a night-light, hair dryer, etc. to make sure. Push the "RESET" button to turn it back on. Most manufacturers recommend testing monthly.
Reasons for concern:
If any of these happen then the outlet may be defective. Have it checked by an electrician.