GFCI vs. AFCI Outlets: What’s the Difference?

If you’ve spent any time around DIY websites and home improvement stores, you’ve likely heard about GFCI vs. AFCI outlets. These important electrical safety devices, technically called “receptacles”, are likely installed in your house right now. But what are they? How to they work? And, if you don’t have them, do you need to run out and get some?

When I was an electrical apprentice, I got shocked so hard it knocked me down. That incident could have been prevented with a GFCI. Later, I spent the better part of a month installing AFCI protection in hundreds of college dorms, only to find out I didn’t have any in my own home. I remedied that quickly, let me tell you! And you can, too.

Find out all you need to know about AFCI vs. GFCI outlets ahead.

What is a GFCI Outlet?

A GFCI outlet (receptacle) protects against electric shock by monitoring the electrical current flowing through the GFCI. If there’s even a tiny difference (4 to 6 milliamps) between the hot and neutral wires, the GFCI assumes the stray current could be going through a person, and de-energizes almost instantly.

To put 4 to 6 milliamps in perspective, 10 milliamps can cause people to lose the ability to let go of an object, and at approximately 100 milliamps you’re at risk of death (depending on several factors like age, weight and exposure time).

What does GFCI stand for?

Ground fault circuit interrupter. GFCI protection can be provided by receptacles or breakers, and they must be installed in a readily accessible location so you can reach them if they trip.

What is a ground fault?

A ground fault is a type of short circuit that happens when a hot wire comes in contact with a part of an electrical installation that’s not supposed to be energized, like an electrical box, or the outside of your toaster or washing machine.

If you happen to be touching the electrified object, the current could go through you unless the circuit quickly de-energizes.

Are GFCIs required?

Yes. Because GFCIs are safety devices, the National Electrical Code (NEC) mandates their use in specific rooms and circuits in new construction, like:

• Bathrooms
• Kitchens
• Sinks (within 6 feet)
• Outdoors
• Basements and crawl spaces
• Garages and outbuildings
• Laundry areas
• Other damp and wet locations, as well as specific appliances like dishwashers and sump pumps

Always check with your local jurisdiction to see what’s required.

Do GFCI outlets go bad?

They can, so it’s a good idea to test them monthly. Have you ever tested yours? People rarely do, so since 2015, GFCIs have had an internal self-test function. Once a GFCI reaches the end of its lifespan, it shuts off power to the device (indicated by a light on the front).

Even with self-testing, you should still do a manual test every month to check the mechanical tripping mechanism.

How to wire a GFCI outlet

There are two sets of connections on a GFCI: Line and Load. These will be clearly marked, and if the GFCI is new there will be a piece of yellow tape over the load connections. Only use the load side if you’re protecting other devices on the same circuit.

To wire a single GFCI, use the line terminals. The hot wire goes on the brass screw, the neutral on the silver. To protect receptacles “downstream” of the GFCI, remove the yellow tape and use the load side screws to connect to the next receptacle.

Always properly ground the receptacle and circuit using the green ground screw.

How to reset and test a GFCI outlet

A GFCI has two buttons: “Test” and “Reset.” To test a GFCI, press the “Test” button until you hear an audible click. This opens the contacts inside the device, indicating that the GFCI is operational. Then, hit the “Reset” button to put things back into place.

If your GFCI trips, push the “Reset” button to reset it. Occasional trips are fine, but if it happens frequently, get it checked out by a licensed electrician.

Another way to test a GFCI is to use a GFCI receptacle tester. Plug the tester in and hit the button. You should hear a click, and the power light will go off. Remove the tester and reset the GFCI using the Reset button.

What is an AFCI Outlet?

An AFCI receptacle (aka outlet) protects your home from fires by constantly monitoring the circuit for evidence of dangerous electrical arcs. An AFCI can sense the difference between brief, regular arcs inherent in certain electrical applications (like a light switch), and abnormal ones caused by a worn wire.

What does AFCI stand for?

Arc-fault circuit interrupter. Just like a GFCI, AFCI protection can be provided by receptacles or circuit breakers, and they must be readily accessible.

What is an arc fault?

An arc fault is a type of abnormal electrical discharge. Damaged wires and improper connections can cause electricity to “jump” between damaged sections of a conductor, or between multiple conductors, placing nearby combustible materials at risk.

Are AFCIs required?

Yes. Almost every room in newly-constructed homes requires AFCI protection, including bedrooms, living rooms, dining rooms, kitchens, laundry rooms, hallways and closets. Basically, the only places you don’t need AFCIs are bathrooms and garages, but always verify with your local code authority.

Do AFCI outlets go bad?

They can go bad, so they should be tested monthly, just like GFCIs.

How to wire an AFCI outlet

Wire an AFCI receptacle just like a GFCI. Use the line side to bring power to the AFCI receptacle, and the load side to provide AFCI protection to the rest of the circuit. Always properly ground the receptacle and circuit using the green ground screw.

How to reset and test an AFCI outlet

To test an AFCI receptacle, push the “Test” button on the front. You should hear an audible click. Reset the AFCI by pushing the “Reset” button. You can also purchase an AFCI receptacle tester (often combined with a GFCI tester) to test the receptacle.

What’s the Difference Between GFCI and AFCI Outlets?

Both AFCI and GFCI protection monitor circuits for electrical faults, and shut off power to the device when they detect a problem. The difference is that AFCIs protect your home from fires, while GFCIs protect people from electrical shock.

GFCI vs. AFCI Outlets: Which Is Right For Me?

In new construction, AFCI vs. GFCI usage will be determined by code requirements. The NEC is published every three years, occasionally adding locations that need protection. States and cities adopt the code at different intervals, so depending on where you live you may have different requirements.

In older homes, you are not required to retrofit your existing fault protection unless you update your wiring. But, because adding AFCI and GFCI protection is as easy as swapping out one receptacle per circuit, you can add these important safety devices at any time. Just follow the NEC to know which one goes where, and make sure they’re readily accessible.

FAQs

How can you tell if an outlet is GFCI vs. AFCI?

It’s a little hard to tell AFCI vs. GFCI, but they’re labeled on the front of the device. You may also see a sticker on the outside of a regular receptacle (outlet) if it is protected by another device. Stickers are provided for this purpose when you buy AFCI and GFCI receptacles.

Are GFCIs or AFCIs surge protectors?

No. Surge protectors suppress voltage spikes from lightning and other power surges. Surge protectors have a maximum number of joules (a unit of energy) they can absorb before you need to get another one. AFCIs and GFCIs have no specified limits of protection.

Do GFCIs or AFCIs prevent fires?

AFCIs prevent fires. GFCIs protect people from shock.

Can I use a GFCI or AFCI breaker instead of an outlet?

Yes. The NEC requires AFCI and GFCI protection, not receptacles or outlets. Breakers are a convenient way to accomplish the required protection.