AFCI Circuit Breakers
AFCI breakers are Arc-Fault Circuit Interrupters. They are similar in appearance to GFCIs (Ground-Fault Circuit Interrupter) breakers and they first came into the market in 1999. They are designed to prevent fires from arcs (sparks) that are not a normal part of a circuit’s operation. Normal and safe arcs occur in switches and in electric motors such as fans and vacuums. They are generally very small or very short in time duration. The devices that produce these normal small arcs are designed to shield and protect people as well as the surroundings from the arcs so there is no fire risk. Dangerous arcs can occur when devices fail, cords are damaged or the wiring becomes faulty as often happens with receptacles using stab-in connections.
The original AFCIs were branch type units designed to trip on 75 amperes of arcing current from the line wire to either the neutral or ground wire. They were required to be installed for all bedroom circuits with the 2002 National Electric Code but did not provide personal protection from ground faults so kitchens, bathrooms, and garages still required GFCI circuit protection.
The 2008 revision of the National Electric Code changed the requirements to include Combination Type AFCIs for all 15A or 20A circuits in a dwelling except kitchens, bathrooms, laundry rooms and unfinished basements, which still require GFCI protection. The combination AFCI added additional protection for series arcing at 5A and personal ground-fault protection which trips the breaker at a 5mA level for ground faults while maintaining the original 70A parallel rating for line to neutral arcing. AFCIs still protect the circuits from the traditional overloads, short circuits and overheating breakers. The Code still does not require AFCIs for kitchens, laundry areas, bathrooms and garages since it requires the use of GFCI breakers or GFCI receptacles in these locations. Adding AFCI breakers to feed GFCI receptacles is not recommended due to the fact that nuisance tripping can frequently occur.
All of the major manufacturers offer combination AFCI breakers so replacing older standard breakers with the new combination AFCIs is possible in all but a small percentage of applications. The primary exception being the “cheater” breakers that feature two circuit in one mounting position that are typically used when a smaller load center has no spare positions for mounting new breakers. Local jurisdictions and local codes vary, so always contact your local officials or local electricians for assistance.
On a final note, if the wiring in your home does not have the combination AFCIs and you have them added for the additional fire protection they offer, contact you r home owner’s insurance agent and let them know your electrical panel was updated. You may qualify for a lower annual premium or other discounts which can help offset the cost of the upgrade.