What is an AFCI breaker?

An arc-fault circuit interrupter, or AFCI breaker, is a safety device installed in your electrical panel that monitors the flow of electricity through a circuit and shuts off power instantly when it detects an arc. An arc occurs when electricity jumps across a gap, creating extreme heat that can ignite insulation, wood framing, or other materials inside walls. Unlike a standard breaker, which responds to overloads and short circuits, an AFCI is sensitive enough to catch the smaller, more subtle electrical faults that produce dangerous arcing.

The National Electrical Code requires AFCI protection on all circuits serving bedrooms, living areas, kitchens, laundry rooms, bathrooms, and crawl spaces in newer homes. Many older homes lack this protection, making electrical panel upgrades a practical way to add AFCI breakers to existing circuits. Some homes use combination AFCI receptacles (outlets) instead of panel-mounted breakers, offering protection at individual points without replacing the breaker itself.

AFCI breakers have dramatically reduced the number of electrical fires caused by arcing. They do occasionally trip on older appliances or equipment that produces harmless arcing patterns, but this is normal behavior, not a defect. If an AFCI breaker trips repeatedly, it typically signals a wiring problem that needs professional inspection.