Buzzword: GFCI

What it means. A receptacle-type GFCI—ground-fault circuit interrupter—resembles a standard duplex wall outlet except that is equipped with a reset button (often red) and a test button (often black). When you plug a fixture or appliance into a GFCI-protected outlet, it monitors the electrical current flowing on the hot and neutral electric conductors. If the GFCI detects an imbalance in current flow, it cuts off power within a few hundredths of a second, thereby reducing the risk of electrical shock or electrocution. The National Electrical Code requires GFCI protection on all outdoor outlets, for countertop outlets in kitchens and bathrooms, and in wet or damp locations like basements and garages—basically anywhere that electricity and water might mix.

You can provide GFCI protection to an outlet and any connected outlets downstream using a receptacle-type GFCI (shown) or to an entire circuit with a circuit-breaker-type GFCI installed in the electric-service panel. If you are using electricity in a damp or wet location where the possibility of electric shock increases, use a portable GFCI device if the receptacle you are using for power is not GFCI protected

Why the buzz? Charles Dalziel, a professor of electrical engineering at the University of California at Berkeley, invented the GFCI in 1961. Today, these life-saving receptacles are in the news because Underwriters Laboratories, which sets the national standards for electrical goods, recently uncovered some faulty 15- and 20-amp 125-volt wall GFCIs from several manufacturers. Under rare conditions, these defective receptacles won't trip when a fault occurs. No injuries have been reported, according to UL, and a product recall has not been issued.

The UL announcement is a reminder that you should test the GFCIs in your home each month and more frequently for those in spots with sustained high temperatures (above 90°F) and high humidity (above 93 percent):
• Push the reset button on the GFCI.
• Plug a lamp into the GFCI and turn on the lamp.
• Push the test button on the GFCI. The lamp should turn off. If it doesn't, hire a licensed electrician to replace the GFCI.
• If the lamp does turn off, push the reset button. The lamp should turn on. If it doesn't, hire a licensed electrician to replace the GFCI.

Testing a GFCI circuit breaker is similar, but first you must identify which receptacles the device protects. Plug a lamp into one of the receptacles you believe is protected and shut off the circuit breaker. If the lamp goes out, it is on that breaker's circuit. Then turn the breaker back on and push the test and reset buttons as described above.—Daniel DiClerico