GFCI vs AFCI: What They Do, Where You Need Them, and Why They Trip
They look similar, they both trip, and they protect against completely different things. Knowing which is which saves a lot of frustration.
GFCI: protects people from shock
A ground fault circuit interrupter compares the current going out on the hot with the current returning on the neutral. If more than a few milliamps goes missing, it is leaking somewhere — very possibly through a person — and the device cuts power in a fraction of a second.
Where they are needed: kitchens, bathrooms, laundry areas, garages, unfinished basements, crawlspaces, outdoors, and near pools and hot tubs. Older Alabama homes predate most of these requirements, and retrofitting is inexpensive.
AFCI: protects the building from fire
An arc fault circuit interrupter listens for the electrical signature of an arc — the fizzing of a damaged cord, a nail driven through a cable, a loose screw on a receptacle. Arcs generate enormous localised heat without drawing enough current to trip a normal breaker, which is exactly how electrical fires start inside walls.
Where they are needed: most habitable-room circuits in newer construction — bedrooms, living rooms, hallways and similar.
Dual function devices
Many circuits now need both. Dual function breakers and receptacles handle the two jobs in one device and are what we fit in most retrofit situations.
Why yours keeps tripping
GFCI nuisance trips
Usually moisture. Outdoor boxes without proper covers, a refrigerator or freezer with a small insulation leak, or long circuits with a lot of accumulated capacitive leakage. Also, GFCI devices have a service life — a fifteen-year-old one that trips randomly is often just worn out.
AFCI nuisance trips
Older vacuum motors, some power tools, certain LED drivers, and — importantly — genuinely damaged cords. Before assuming the breaker is oversensitive, check the cords of anything that runs on that circuit for crushing or heat damage.
The test button is not decoration
Press the test button on every GFCI in the house monthly. If it does not trip, or does not reset, replace it. It is a two-minute job that people skip for years.
We fit GFCI and AFCI protection anywhere in Alabama — see outlet and wiring repair or call (888) 633-7804.