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
AFCI or AFCI/GFCI circuit breaker to match the amperage of the circuit Flashlight Screwdrivers Non-conductive floor mat
Instructions
Warning
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. 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.
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. 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.
