Protective devices capable of responding to overloads and short circuit, such as circuit breakers, have been available for a number of years. Newer technologies now provide enhanced protection from arcing or ground-faults, which may prevent fires or shock.
AFCIs (arc-fault circuit-interrupters)
When an electrical switch is opened or closed, an arc, or discharge of electricity across a circuit, occurs. Unintentional arcs can occur at loose connections or where wires or cords have been damaged. Such arcs can lead to high temperatures and sparking, possibly igniting combustibles. AFCIs (arc-fault circuit-interrupters) protect against fire by continuously monitoring the electrical current in a circuit and shutting off the circuit when unintended arcing occurs. These devices are designed to discriminate between unintended arcing and the type of arcing that occurs when a switch is operated. AFCIs can be installed as a circuit breaker in a panelboard or as a receptacle outlet.
AFCI protection is required by the 2017 National Electrical Code®
(NEC) for 15 and 20 amp circuits that serve outlets and devices in all areas of new residential construction, excluding bathrooms, garages, and outside areas. In addition to new construction, when receptacles are replaced in areas where AFCI protection is now required, the replacement receptacle must have AFCI protection. Prices of AFCI type circuit breakers at several national building supply chains are in the range of $35 to $50 per unit, while receptacle type devices are in the range of $20 to $30.
GFCIs (ground-fault circuit-interrupters)
A ground-fault is an unintentional electrical path between a source of electrical current and a grounded surface. Electrical shock can occur if a person comes into contact with an energized part. GFCIs (ground-fault circuit-interrupters) can greatly reduce the risk of shock by immediately shutting off an electrical circuit when that circuit represents a shock hazard (i.e., a person comes in contact with a faulty appliance together with a grounded surface). GFCIs can be installed in a circuit breaker panelboard or directly in a receptacle outlet. GFCIs can be installed as a circuit breaker in a panelboard or as a receptacle outlet.
GFCI protection is required by the 2017 NEC for newly installed and replacement 15 and 20 amp receptacles on kitchen countertops, in bathrooms, outdoor areas, unfinished basements and crawl spaces, garages, boathouses, laundry areas, and within 6’ of sinks, bathtubs and shower stalls. GFCI protection is also required for certain appliances that have a history of being a shock hazard. Drinking fountains, vending machines, dishwashers and boat hoists are examples of appliances that require GFCI protection.
- All AFCIs and GFCIs, whether circuit-type or breaker-type, should be installed by a qualified electrician.
- Test AFCIs and GFCIs after installation and once a month thereafter to make sure they are working properly.
- Replace defective AFCIs and GFCIs immediately. A defective device may create a false sense of security to those who do not know that it is non-functional.
- Choose AFCIs and GFCIs that carry the label of an independent testing laboratory and always follow the manufacturer's instructions.