This life-saving device is called a ground-fault-circuit interrupter, or GFCI.

An unintentional electric path between a source of current and a grounded surface is called a ?ground fault?. Ground faults occur when current is leaking somewhere. If humans provide a path to the ground for this leakage, they can be seriously injured or electrocuted. Ground faults are often the result of damaged cords or appliances, poor insulated wires, or mishandling, such as dropping an appliance in water.

GFCI's are products designed to prevent injury or death from electric shock by detecting ground faults at very low levels. If a GFCI senses even minimal current leakage in an electrical device, it assumes a ground fault is taking place. It then interrupts the power fast enough to prevent injury to anyone in normal health.

To comply with National Electrical Code, many homes built since 1973 (US) have some GFCI protection. However, the US Consumer Product Safety Commission estimates that as many as 70 percent of all existing dwellings have no such protection.

Several of the nations leading electrical safety organizations, such as the DPSC, NEMA and UL encourage all consumers to equip their homes with GFCIs. Recommended areas to protect are kitchens, bathrooms, garages, crawl spaces, unfinished basements and outdoor receptacles-areas where many electrical hazards exist.

A consumer has three types of GFCIs to choose from for home use: wall receptacle, circuit breaker, and portable plug-in.

The three types of GFCIs designed for home use are readily available, inexpensive, and rather simple to install. Modern electronics and engineering practices, coupled with very rigorous functional testing standards, have made contemporary GFCIs durable, reliable, and extremely effective.

GFCI outlets are readily available at any home improvement center and many other stores, and it is physically possible for a homeowner to purchase and install one. However, we recommend that a competent, licensed electrician do any work on your home's electrical system that involves exposure to live components. However, if you decide to tackle the installation of a GFCI receptacle, keep the following in mind:

GFCI receptacles are manufactured with two sets of terminals on the back. These sets are plainly marked, ?Line? and ?Load?. The reason for two sets of terminals is to allow the GFCI receptacle to actually provide GFCI protection to any other receptacle supplied from it-remember the ?daisy chain??

In every case, however, no matter whether the receptacle you are working on is the first or the last receptacle in the daisy chain, the wires that bring the electricity to the receptacle must be connected to the terminals marked ?Line?!

If the receptacle that you are replacing supplies other receptacles farther along in the chain, then the wires supplying the downstream receptacles must be connected to the terminals marked ?Load?.

We cannot overemphasize the need to properly wire GFCI outlets! These receptacles have complex circuitry that allows them to provide life-saving protection. If one outlet is wired incorrectly so that the electrical supply is not connected to the Line terminals, then it will not work properly. This usually means the receptacle itself is not GFCI protected and will not protect you when you need it most. Do not assume that if the ?test? button works that the outlet is properly installed.

As stated earlier, electrical components in your home can be very dangerous. Many people prefer to play it safe and hire a licensed electrician.

In homes equipped with circuit breakers, a GFCI circuit breaker may be installed in a panel box to give protection to selected circuits. This type of GFCI serves a dual purpose. It shuts off electricity in the event of a ground fault. It also will trip when a short circuit or an overload occurs. A qualified electrician should install GFCI circuit breakers in the home.