This piece was originally published in the May 2018 issue of electroindustry.
Danny Abbate, Industry Director, Building Infrastructure Division, NEMA
Ground-fault circuit interrupters (GFCIs) were first released to the public market in the late 1960s. They were originally required by the National Electrical Code® only for exterior spaces such as swimming pools. Toward the end of the 1970s and into the 1980s, GFCIs were mandated for kitchens, bathrooms, unfinished basements, and several other spaces. Today, GFCIs are required near most wet areas within a residential dwelling.
As the use and requirements of GFCIs increased, the yearly number of electrocution deaths began to decline. Studies published by the Consumer Product Safety Commission show that in the mid-1970s, there were 500 to 600 electrocution deaths per year. By the 1980s, as the requirements for GFCIs increased to guard against electrocutions in more household spaces, the numbers decreased to the 200 to 300 range. From the year 2000 and beyond, the number of deaths decreased even further to less than 200 per year as the number of GFCIs in the market has reached almost 100 million. GFCIs have a direct lifesaving effect.
GFCIs work by monitoring the amount of electrical current flowing through an outlet. If there is an imbalance in the current from the hot side (small hole on the right) to the neutral side (large hole on the left), the GFCI will interrupt the circuit as fast as one-thirtieth of a second and protect the end user from electric shock.
GFCIs typically come in several types, including receptacles, circuit breakers, and even portable cord-connected versions. Receptacles protect the end user at the point of use, where electronics and appliances are plugged into a wall. GFCI receptacles can also provide downstream GFCI protection through multiple-location wiring, which protects the first GFCI receptacle and every receptacle downstream of it (including standard receptacles) in the same circuit. Circuit breaker types are used within an electrical circuit breaker panel, and when installed, the GFCI protects all the receptacles downstream from that breaker.
GFCIs are now ubiquitous for interior and exterior applications, and for good reason. They have proven to be an extremely effective deterrent to electric shock, with wide availability and easy installation. As the number of electrically operated devices and appliances continues to rise, GFCIs will continue to protect the public.