The National Electrical Council, which publishes ground-fault circuit interrupter requirements from year to year, generally requires that GFCIs be installed on circuits wired near plumbing fixtures and other areas where electrical wiring may come in contact with water. As of 2014, this includes residential wiring intended to connect to dishwasher and laundry units.
A GFCI, which keeps electricity from flowing where it shouldn't, prevents fires and electrocutions. GFCIs are designed to shut off power quickly when they detect a difference in current flowing out and in along the circuit conductors. A GFCI is not itself a circuit. Rather, it is a component that monitors the rest of the circuit. Circuits without GFCIs do not differ in any substantial way from circuits without them, although they are considered less safe to use.
The NEC, which is the governing body over electrical regulations in the United States, changes GFCI requirements on an almost annual basis, making information on these requirements highly time sensitive. As of 2014, the NEC require GFCIs to be installed on construction sites with single phase, 15- and 20-ampere outlets; on residential buildings with outdoor 120-volt, 15- and 20-ampere outlets; and on outlets within 15 feet of an indoor pool. GFCI protection is also required in garages, bathrooms and kitchens.
Since 2014, the NEC has also required that GFCIs be installed on 125-volt, single-phase, 15- and 20 amp outlets in laundry rooms, and on 125-volt, single-phase, 15- and 20 amp outlets in commercial garages and service bays. They are also required in outlets that supply electricity to kitchen dishwashers.