Dishwashers work by pulling in water from the water supply in the location where they are installed. They take this water and mix it with soap in the dishwasher cabinet.
This soapy water mixture is then sprayed on the dishes inside by a sprayer arm. A rinse cycle then cleans the dishes of any soap residue.
Finally, a heating element in the dishwasher heats up to dry the dishes inside.
GFCI circuits are usually installed in locations that have a high moisture content, such as kitchens and bathrooms. These sockets have two switches on the outside, typically called "Test" and "Reset".
The "Test" switch allows the owner to test out the GFCI operation if the appliance plugged into the circuit is suddenly exposed to water, while the "Reset" function allows the socket to reset to normal operation after it trips. GFCI circuits provide safety for electrical appliances in wet locations, such as areas near sinks, by automatically switching off when a voltage leak is detected.
Dishwashers connect to the electrical power in a couple of different ways. A portable dishwasher simply plugs into the nearest outlet.
Built-in dishwashers are hard-wired into the home electrical circuit. In this case, the dishwasher can only be totally cut from power by turning off the circuit breaker.
Installing a Dishwasher on a GFCI Circuit
Contact your local city council building authority or other governing board about the codes for dishwasher installation in your area. Some municipalities may require dishwashers to be installed on a GFCI circuit while others may not.
In general, the best option is to go ahead and wire the dishwasher into the home electrical system through the terminal points provided on the dishwasher. According to "Popular Mechanics," some manufacturers do not recommended connecting these appliances to a GFCI.
However, your outlet for the dishwasher may be under the sink, in which case some contractors recommended a GFCI. It's best to check with your manufacturer.
Portable dishwashers should be plugged into GFCI terminals when available.