NEC Article 422 — Appliances: Dedicated Circuits, Disconnects, and the Dishwasher GFCI Rule

NEC 422 covers appliances — the rules for hardwired and cord-connected loads in dwellings. The most-cited sub-rules:

Dishwasher GFCI required (422.5(A) / 210.8 expansion): since the 2020 NEC, dishwashers (whether hardwired or cord-and-plug connected) must be GFCI-protected. The protection can be at the receptacle, at a GFCI breaker, or at a GFCI device upstream. NJ adopted this with the 2023 NEC update.

Disposal disconnect (422.31(B)): every motor-operated appliance over ⅛ HP needs a disconnect within sight of the motor or a lockable breaker. Most kitchen disposals (½ HP, 1 HP) trigger this. The under-sink toggle switch satisfies it for cord-and-plug units.

Range circuit (422.10): electric ranges need a dedicated branch circuit. NEC 220.55 sets the demand factor for the load calculation (typically 8 kW for a single household range up to 12 kW nameplate).

Dryer circuit (422.10 + 220.54): electric clothes dryers need a dedicated 30 A branch circuit minimum. Load calc: minimum 5,000 VA per dwelling unit per 220.54.

Water heater (422.13): electric water heaters are continuous loads. The branch circuit must be sized at 125% of the nameplate. Most 4,500 W water heaters draw 18.75 A continuous, requiring a 30 A breaker and #10 CU minimum (often #8 CU on long runs for voltage drop).

Microwave / cooktop / wall oven — each gets its own dedicated 20 A or 30 A circuit. Counter-top microwaves on the appliance circuit are technically allowed but discouraged for nuisance-trip reasons.

Built-in appliance height for over-current protection (422.31): the disconnect / overcurrent device for any built-in appliance must be readily accessible. A breaker panel in the same room (or visible from it) usually satisfies this.

The NJ-specific microwave footprint: older Hoboken brownstones often have undersized service, and adding a high-wattage microwave puts the kitchen circuit over 80% loading. Run the load calc before adding ANY new dedicated kitchen circuit on a service that's already under stress.

For the load-calc impact of new appliances, use the free Malfettone Load Calculator at /tools/load-calculator. It has presets for water heater, dishwasher, disposal, range, dryer, microwave, and the demand factors per Table 220.55.