A “GFCI” is a ground fault circuit interrupter. A ground fault circuit interrupter is an inexpensive electrical device that, if installed in household branch circuits, could prevent over two-thirds of approximately 300 electrocutions still occurring each year in and around the home. Installation of the device could also prevent thousands of burn and electric shock injuries each year.
The GFCI is designed to protect people from severe or fatal electric shocks because a GFCI detects ground faults, it can also prevent some electrical fires and reduce the severity of other’s by interrupting the flow of electrical current.
Have you ever experience an electric shock? If you did, the shock probably happened because your hand or some other part of your body contacted a source of electrical current and your body provided a path for the electrical current to go to the ground, so that you received a shock.
An unintentional electric path between a source of current and a grounded surface is referred to as a “ground-fault.” Ground faults occur when current is leaking somewhere, in effect, electricity is escaping to the ground. How it leaks is very important. If your body provides a path to the ground for this leakage you could be injured, burned, severely shocked, or electrocuted.
Some examples of accidents that could occur because of this hazard:
- Two children, ages five and six, were electrocuted in Texas when a plugged-in hair dryer fell into the tub while they were bathing.
- A three-year-old girl in Kansas was electrocuted when she touched a faulty countertop.
- These two electrocutions occurred because the electrical current escaping from the appliance traveled through the victim to ground (in these cases, the grounded plumbing fixtures). Had a GFCI been installed these deaths would probably have been prevented because a GFCI would have sensed the current flowing to ground and would have switched off the power before the electrocution occurred.
How the GFCI works:
In the home’s wiring system, the GFCI constantly monitors electricity flowing in a circuit, to sense any loss of current. If the current flowing through the circuit differs by a small amount from that returning, the GFCI quickly switches off power to the circuit. The GFCI interrupts power faster than the blink of an eye to prevent a lethal dose of electricity. You may receive a painful shock, but you should not be electrocuted or receive a serious shock injury.
How it applies to your home:
Suppose a bare wire inside an appliance touches the metal case. the case is then charged with electricity. If you touch the appliance with one hand while the other hand is touching a grounded metal object, like a water faucet, you will receive a shock. If the appliance is plugged into an outlet protected by a GFCI, the power will be shut off before a fatal shock would occur.
Availability of GFCI’s:
Three common types of ground fault circuit interrupters are available for home use;
* Circuit breaker type-
In homes equipped with circuit breakers rather than fuses, a circuit breaker GFCI may be installed in a panel box to give protection to selected circuits. The circuit breaker GFCI serves a dual purpose- not only will it shut off electricity in the event of a “ground-fault,” but it will also trip when a short circuit or an over load occurs. Protection covers the wiring and each outlet, lighting fixture, heater, etc. served by the branch circuit protected by the GFCI in the panel box.
* Portable type
Where permanent GFCI’s are not practical, portable GFCI’s may be used, one type contains the GFCI circuitry in a plastic encio-sure with plug blades in the back and receptacle slots in the front. It can be plugged into a receptacle, then, the electrical product is plugged into the GFCI. Another type of portable GFCI is an extension cord combined with a GFCI. It adds flexibility in using receptacles that are not protected by GFCi’s.
Where GFCI’s should be considered:
In homes built to comply with the National Electrical Code (the Code), GFCI protection is required for most outdoor receptacles (since 1973), bathroom receptacle circuits (since 1975), garage wall receptacles in crawl spaces and unfinished basements (since 1990).
Owners of homes that do not have GFCI’s installed in all those critical areas specified in the latest version of the Code should consider having them installed. For broad protection, GFCI circuit breakers may be added in many panels of older homes to replace ordinary circuit breaker. For homes protected by fuses, you are limited to receptacle or portable-type GFCI’s and these may be installed in areas of greatest exposure, such as the bathroom, kitchen, basement, garage, and outdoor circuits.