What is the difference between a Combination Arc Fault Circuit Interrupter (CAFCI) and an Arc Fault Circuit Interrupter (AFCI) circuit breaker?
Sunday, July 22, 2018
The CAFCI is a new version of the older ACFI breaker. Both trip like a standard circuit breaker when the circuit is overloaded with too much current or there is a short circuit, and the AFCI also trips when there is parallel arcing (hot-to-neutral or an arc to ground) in the protected circuit. Because arcing (you might call it “sparking”) in wiring is one of the the leading causes of house fires, this protection is important. Circuits serving bedrooms have been required to have AFCI-protection since the beginning of this century.
But AFCI breakers did not recognize series arcing (between a small gap or frayed area in the same wire), so the combo-AFCI or CAFCI was developed, which has that additional capability. Beginning in 2008, the National Electric Code (NEC) has required the installation of combination-type ACFIs in all 15 and 20-amp circuits, with the exception of laundries, kitchens, bathroom, garages, and unfinished basements—which are locations where Ground Fault Circuit Interrupter, also called GFCI, protection of the circuits is required. CAFCI, AFCI, and GFCI breakers all have test buttons, like in the photo above.
So, essentially, a CAFCI is the new and improved version of an AFCI. Older AFCI breakers by Square D/Homeline (pre-combo) have green or blue test buttons; and while both types of breakers by Eaton Cutler-Hammer are clearly marked on the front of the breaker, like in the photo above.The label indicating that a breaker is a COMBINATION AFCI is hidden behind the dead front (cover plate of the panel box) and noted in very small letters along with the other listing information on the face of the breaker for Square/Homeline breakers, like the one shown below. But they are recognizable by the white color of the test button.
Also, see our blog post What is the difference between GFCI and AFCI circuit breakers?
Here’s links to a collection of our other blog posts about AFCI and GFCI RECEPTACLES AND CIRCUIT BREAKERS:
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