Circuit Interrupters Reduce Risk of Home Electrocutions
According to the U.S. Consumer Product Safety Commission, installing a ground-fault circuit interrupter (GFCI) in household branch circuits could prevent the more than 200 electrocutions and thousands of electric shocks and burns that occur in and around the home each year.
Of course, proper installation of the device is essential.
The GFCI is an electrical circuit that is built into a device such as a circuit breaker or an outlet. It is designed to protect people from severe or fatal electrical shocks. It can switch off the power to the device in a fraction of a second (about 1/40th of a second), which is fast enough to prevent injury to anyone in good health.
The GFCI is activated when the circuit senses an imbalance in the electrical current between the hot and neutral line, which is as small as 5 milliamps (5/1000 of an amp). At 50 milliamps, it takes only 3 1/2 seconds for a person’s pulse to stop.
An imbalance in the electrical current occurs when an unintentional electrical path, known as the ground fault, exists between the current and a grounded surface. Without a GFCI, a person providing the path to ground could be severely shocked, burned or electrocuted.
Installation
A GFCI outlet receptacle is ineffectual if it is not properly installed. With a regular duplex outlet receptacle, there are two terminals for the hot wire and two terminals for the neutral wire. It doesn’t matter which hot terminal you connect the hot wire to. The same holds true for the neutral wire. It’s a different story, however, with a GFCI receptacle.
Markings on the back of GFCI outlets indicate LINE and LOAD. The wires from the circuit breaker or fuse panel box must be connected to their respective LINE terminal screws.
If instead they are connected to the LOAD terminals, the GFCI outlet will not provide protection against a shock hazard. The LOAD terminals are for the connection of additional outlets to be protected by the GFCI. This is referred to as “feed-through protection.”
When the line wires are connected to the LOAD terminals and the GFCI trips (activated), power to the feed-through outlets is interrupted, but power to the GFCI outlet receptacle itself is not switched off. Consequently, there will be no protection against a shock hazard resulting from any appliance plugged into the GFCI outlet.
Maintenance
All GFCIs have test buttons for consumers to check whether they are functioning properly. Pushing the test button will switch off the power to the GFCI outlet and any feed through outlets. If power is not interrupted, either the GFCI outlet is not wired correctly, or it is faulty.
Manufacturers recommend that the GFCIs in your home be checked monthly.
