One of the questions I am frequently asked by clients is why GFCI outlets are recommended or required in some locations and AFCI protection recommended in other locations. In some cases there is confusion regarding what they are and what they do.
Ground Fault Circuit Interrupter requirements were introduced in the 1971 National Electrical Code. The function of the GFCI is to protect people from the deadly effects of electric shock that could occur if parts of an electrical appliance or tool become energized due to a ground fault. The GFCI monitors the imbalance of current between the ungrounded (hot) and grounded (neutral) conductor of a given circuit. When the GFCI detects a ground fault, electricity to the outlet will be cut in less than 1/10th of a second. Don't let the name confuse you, GFCI’s will operate on a circuit that does not have an equipment-grounding conductor. One GFCI will protect all electrical outlets downstream in the electrical circuit when wired properly.
Normally the GFCI is required in any wet locations or within 6 feet of any water source such as bathroom vanities, kitchen sinks, saunas, hot tubs, crawlspaces, garages and outdoors. If in doubt contact a Home Inspector or electrician. If your home was built before these codes were put in place you are not required to replace the non GFCI outlets but it is highly recommended.
Arc Fault Circuit Interrupter requirements were added to the National Electrical Code in 1999. The AFCI’s were required to be installed for protection of bedrooms or sleeping areas in 2005. AFCI’s are designed to detect a wide range of arcing electrical faults to help reduce the electrical system from being an ignition source of a fire. Conventional overcurrent protective devices do not detect low level hazardous arcing currents that have the potential to start electrical fires. Electrical fires take many lives and damage or destroy significant amounts of property. The objective is to protect the circuit in a manner that will reduce its chances of being a source of an electrical fire.
The 2014 National Electric Code requires 15A or 20A, 120V branch circuits in dwelling units supplying outlets in family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or similar rooms/areas must be protected by a listed AFCI device. Once again, if your home was built prior to this you are not required to add the AFCI protection at this time.
If you choose to add GFCI or AFCI protection to your home it is recommended that you consult a licensed electrician to insure the job is done safely and to code.