If a branch circuit supplies a single non-motor-operated appliance, what is the maximum rating of overcurrent protection if the appliance is rated at 13.3 amperes or less?

The correct answer is based on the National Electrical Code (NEC), which states that for a branch circuit supplying a single non-motor-operated appliance that is rated at 13.3 amperes or less, the maximum rating for overcurrent protection is specifically determined to be 15 amperes. This is because the overcurrent protection must be sized to provide adequate protection for the appliance without exceeding its rating, ensuring safety in case of any faults or overload situations.

While an appliance rated at 13.3 amperes may be protected by circuits rated at 20 amperes or higher, according to NEC guidelines, it is considered good practice to use the most appropriate overcurrent protection, which in this case is 15 amperes. This allows for the safe operation of the appliance without unnecessarily large protection that could lead to unsafe conditions.

As a result, while 20 amperes does exceed the appliance's rating, the need for conformity with the NEC and maximum safety defines 15 amperes as the correct choice for overcurrent protection in this scenario.