How to Install an AFCI or GFCI/AFCI Combo Circuit Breaker

Combination AFCI/GFCI circuit breaker


Requirements for GFCI (ground fault circuit interrupter) protection have been in place for many years, but more recently, the National Electrical Code (NEC) began requiring another form of protection, known as arc fault circuit interrupters (AFCI). In 2002, this protection became necessary for bedrooms, and in 2014, section 201.12 of the code required all new construction to provide AFCI protection in kitchens and laundry rooms, as well as bedrooms. Then, in 2017, the requirement was expanded to require AFCI protection in virtually every living space in the home.

Basics of AFCI Protection

An arc fault is essentially a spark between contacts in electrical wires. Similar to lightning, it is a highly energized plasma discharge that jumps an air gap from an energized source to a grounded location. (Note: the air gape is usually jumped when an energized part is trying to fully contact its terminal and arcing occurs as it is trying to make contact; and when a hot wire touches a grounded surface and sparks fly.) As the discharge occurs, it creates very high heat and can melt the insulation around wire conductors and start fires in combustible materials. Unlike a ground fault, where the danger is mostly shock, an arc fault's primary danger is its ability to start a fire.

There are two standard methods of providing arc-fault circuit interrupter protection to the circuits that require it. Special arc fault protector outlet receptacles are available, which can be installed in place of standard receptacles. But because the AFCI requirements include all devices on the entire circuit, the more common solution is to install an AFCI circuit breaker, which replaces a standard circuit breaker and protects the entire circuit from arc faults.

Where the code requires both GFCI and AFCI protection, you can buy and install combination GFCI/AFCI circuit breakers that protect against both ground faults and arc faults.

Project Overview

Installing an AFCI or AFCI/GFCI combination circuit breaker is quite similar to installing a regular circuit breaker, and it is exactly like installing a GFCI circuit breaker. With a standard circuit breaker, there is only one wire connected to the breaker—the circuit's hot wire. But with both AFCI and GFCI circuit breakers, both the hot and neutral circuit wires are attached directly to the breaker, while a separate coiled pigtail wire from the breaker is connected to the neutral bus bar in the panel. These days, most brands of panel manufacturers make a "plug-on neutral" breaker that eliminates the coiled pigtail by using the mounting clip to attach to the neutral bar itself.

Tools and Supplies You Will Need


  1. Purchase a AFCI or GFCI/AFCI Circuit Breaker

    First, obtain an AFCI or GFCI/AFCI circuit breaker that matches the amperage of the circuit (normally 15 or 20 amps), and that is designated for your service panel. Different manufacturers have slightly different connection styles for circuit breakers, so you need to use breakers that match your panel. For example, if you have a Square D or Siemens circuit breaker panel, buy breakers from the same manufacturer as your panel. The problem with Square D is that they make two primary versions, HomeLine and QO. Eaton makes two as well: a CH and a BR. The HomeLine and QO are not interchangeable with one another, and neither are Eaton's CH and BR. Third-party manufacturers of circuit breakers will generally specify the panel manufacturer they are matching—such as "Square D by Schneider."

  2. Turn Off the Power and Remove the Panel Cover

    Place a non-conductive rubber floor mat on the floor in front of the main circuit breaker panel. While standing on the mat, open the door of the panel and shut off the main circuit breaker. Also flip the switch on the circuit breaker you're planning to replace to the OFF position.

    Next, remove the front cover on the panel by removing the screws around the perimeter of the cover. Set the screws and the panel cover aside.

    • Note: accidents are rare, but experienced electricians generally insulate themselves while working at the service panel to minimize any risk of shock. This means wearing insulated boots and standing on an insulated, non-conductive floor mat while working in the panel. NEVER do this work while barefoot or in stocking feet.
  3. Remove and Disconnect the Old Circuit Breaker

    Unsnap the circuit breaker from the clips holding it into the panel. Usually, this can be done by simply gripping the switch on the breaker and pulling outward— sometimes it helps to lever the breaker at an angle toward the outside of the panel. This action will snap the breaker's connection from the blades on the hot bus bar.

    Take care not to touch any other parts in the panel, especially the hot bus bars to which the breaker is connected. Even with the main breaker turned off, there may be live power flowing through the bus bars.

    Pull the breaker slightly out from the panel, then use a screwdriver to disconnect and remove the black circuit wire. Next, find the white neutral wire from the circuit, and disconnect it from the neutral bus bar in the panel. Be careful not to touch any other parts with the metal screwdriver as you disconnect the neutral wire. Pull the wire out slightly from the panel.

  4. Connect the New Breaker

    Begin connecting the new AFCI or combo breaker by turning its switch to the OFF position. Then, connect the coiled white pigtail wire on the circuit breaker to one of the terminals on the neutral bus bar in the panel. This is done by inserting the bare end of the wire into one of the openings in the neutral bus bar, then tightening down its setscrew.

    Next, take the white neutral circuit wire and connect it to the circuit breaker terminal lug labeled LOAD NEUTRAL. Then take the circuit's black hot wire and connect it to the breaker's terminal lug marked LOAD POWER.

  5. Insert the New Breaker

    Grip the circuit breaker at a slight angle, then hook the base of the breaker onto the panel mounting rail/recess. Align the breaker's connection plug on the back of the breaker with the panel's HOT bus bar knife blade, and snap the breaker into place on the main bus bar.

  6. Turn On the Power

    Replace the panel cover, then turn on the main circuit breaker. Turn on the AFCI or combination circuit breaker. Test the breaker by pressing the test button. The switch should snap to the OFF position. If it tests correctly, reset the breaker by flipping the switch back to the ON position.


Any electrical repair carries a risk of shock to inexperienced DIYers, and working in the main service panel can be especially dangerous, since you are working near the main power source where 100 amps or more are flowing through the metal bus bars in the panel. Replacing a circuit breaker is actually quite simple if you work carefully while respecting the inherent danger of the power source. But if you are not confident of your knowledge or skill level, replacing a circuit breaker is a job that should be left to a professional.