What is an AFCI, or Arc Fault Circuit Interrupter and why do I need them?

What is an AFCI, or Arc Fault Circuit Interrupter and why do we need them?

afci receptacle afci breaker


About 15 years ago we began to see a change to the electrical code beginning to require AFCI protection on branch circuits within a home.  So what exactly are they and why do I need them?  Hopefully in this post I can help explain the answers to these questions and provide some clarity into why we need to install them when working on your home.

Arc Fault Circuit Interrupters come in several different types that can be installed in your home.  There are circuit breakers that have built in AFCI protection that can be installed directly into your panel, and there are receptacles that have AFCI protection that can be installed anywhere within a circuit, but preferably at the head of the circuit.  Is there any advantage in using one over the other?  Circuit breakers with some exceptions will only work on a 2 wire circuit.  So if you have a home that was wired using 3 wire home runs they won’t work.  This is where the receptacles come in as they can be installed in the circuit within the home outside of where the neutral conductor is shared as in a 3 wire circuit.  There are also combination AFCI/GFCI receptacles that can be installed where both protections are required.

So the big question is, what do they do?  Like the name of them says, they protect against arc fault conditions such as an arcing appliance or a loose connection that is creating an arc.  They are designed to protect the branch circuit from this arcing which could potentially create a fire if this arcing is near a combustible source.  One thing to realize though is that an AFCI does not protect against an overcurrent situation.  This is what your breakers are for, they will detect an overloaded condition or a short circuit condition and open the circuit.  Arc Fault Circuit Interrupters detect smaller erratic current conditions that are caused by arcing.

One question I’ve been asked is what is the difference between a GFCI and an AFCI?  To explain it in simple terms, a GFCI, or Ground Fault Circuit Interrupter is to sense a ground fault and protect people from getting a dangerous electrical shock.  An AFCI is there to protect the branch circuit and the equipment attached to the branch circuit from an arcing condition which could lead to a fire.

Within the latest code update AFCI protection is required in homes on all branch circuits supplying outlets or devices installed in kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas. This is pretty much everywhere in a home with the exception of garages, outdoors, and bathrooms.  This could possibly change with the 2017 code update.  Any time a circuit is added in one of these areas or an existing circuit is extended, arc fault circuit interrupter protection is required.  So, let’s say you would like to add a few can lights in your living room, these need to be arc fault protected.

If you would like to speak to a professional about arc fault protection or need assistance installing some in your home, please contact us at HB Electric Solutions and we will do our best to come up with a solution that works for you.