What is the minimum amperage rating for a branch circuit serving laundry outlets in a dwelling unit?

The minimum amperage rating for a branch circuit serving laundry outlets in a dwelling unit is 20 amperes. This requirement is specified in the National Electrical Code (NEC), recognizing that laundry equipment, such as washers and dryers, can draw significant current during operation. A 20-amp circuit is suitable to handle the load usually associated with laundry appliances while ensuring that there is adequate capacity to accommodate the operating conditions without tripping breakers or causing potential hazards.

Choosing a lower amperage, like 15 amperes, would not provide sufficient capacity for most laundry appliances, which could lead to nuisance tripping and limit their functionality. Higher amperage ratings, such as 30 or 40 amperes, are not typically necessary for standard residential laundry circuits and may exceed what is required, potentially leading to installation of larger wiring than is appropriate for the appliances being served.