For a dwelling unit, what is the voltage standard used for sizing appliance circuits?

The voltage standard used for sizing appliance circuits in a dwelling unit is 120 volts. This standard is established in the National Electrical Code (NEC), which specifies that general-purpose outlets in residential settings typically operate at this voltage level.

In residential applications, most of the common appliances and receptacles, such as those for kitchen equipment, lamps, and other household devices, are designed to work with 120 volts. This ensures compatibility and safety across the majority of residential appliances and devices.

While other voltage levels, such as 240 volts, are present for larger appliances (like dryers and ovens) or specific industrial applications (such as 208 and 480 volts), they are not the standard for general appliance circuits in residences. Sizing circuits correctly is vital to ensure that the wiring can safely handle the current drawn by these appliances, which further emphasizes the importance of adhering to the 120-volt standard in residential settings.