What is AFCI and what does it do?
Arc fault circuit interrupters have built-in logic to detect abnormal arcing in wiring from causes such as loose connections or degraded insulation. AFCI devices are smart enough to know the difference between what it considers “normal arcing” (i.e. a light switch’s contacts arcing) and abnormal arcing.
When abnormal arcing is detected, the AFCI will cut off power. Doing so can prevent fires by stopping the thermal energy created during the arcing from setting fire to surrounding materials in your home.
This sounds great, right?
Pro Tip: The best combination
The best way to fully protect your home is one of two methods: using a combination AFCI/GFCI breaker, or using an AFCI breaker and GFCI outlets.
Combination AFCI/GFCI breaker
A combination AFCI/GFCI breaker will give AFCI protection of the wiring in the circuit from causing fires if it becomes faulty, and the GFCI portion of the breaker will give protection to all outlets on that circuit. The main downside to this is cost- combination breakers are more costly than the next method.
AFCI breaker and GFCI outlets
Installing an AFCI breaker will give AFCI protection of the wiring in the circuit from causing fires if it becomes faulty. The wiring itself doesn’t need GFCI protection, so GFCI outlets can be installed in required locations. This option is cheaper than installing a combination breaker but is more labor-intensive.
Installing GFCI and standard outlets downstream
Another option if you know you have multiple outlets wired in parallel is to add a GFCI at the first outlet location in the branch. All downstream outlets will be protected by the GFCI in the upstream location.
I personally don’t care for this method and would rather install a GFCI breaker. I’ve seen electrical inspections fail for outlets that were actually protected by an upstream GFCI, but the inspector did not realize it.
Additionally, I have seen GFCI outlets in a basement that feed GFCI outlets in a garage. Now, add the GFCI outlet to the utility sink that was branched from the GFCI in the garage. That’s a potential of three different places for a GFCI to have to be reset. A GFCI breaker solves this issue by consolidating all those locations to one reset at the main panel.
Now you know that you can change an outlet easily. Hopefully, the additional considerations for which type of outlet you need for a location in the home will allow you to critically think whether you should replace that three-prong outlet with another of the same or spring for the GFCI outlet.