When planning what circuit breaker to use for a freestanding or built-in dishwasher, you need to know how many amps the dishwasher uses to determine the size of the breaker. If you use a breaker that is too small, you will continually trip the breaker when you try to run the unit.
Built-in and portable dishwashers have an operating load of 13.5 amps. This means that the amperage of the circuit breaker must be higher than the amps required by the unit.
Circuit Breaker Amperage
Dishwashers need a single-pole breaker that has at least 15 amps. However, if you are running a garbage disposal on the same circuit breaker that you will operate the dishwasher, you need to use a 20 amp breaker. The single pole breaker supplies 120 volts to the breaker and only requires one slot on the circuit breaker panel.
Ground Fault Circuit Interrupters (GFCI)
If you have a portable dishwasher, you need to use a GFCI wall outlet, but for a built-in dishwasher that is directly wired, you will use a GFCI circuit breaker. The ground fault interrupter will cut power to the dishwasher in 1/40 second, according to the Occupational Safety and Health Administration. The power is cut to the dishwasher if a line to ground fault occurs or if there is a short circuit or circuit overload while the dishwasher is running.
Plugging the Dishwasher In
When you plug in a portable dishwasher, you must not use an extension cord or an adapter for the plug end. The dishwasher plug has two prongs and a third prong under the two prongs, which is the ground. You must never cut off the ground prong. After you connect the dishwasher faucet attachment to the faucet, you then plug the power cord into the wall outlet. After the unit is plugged in, you can turn on the water.