Conductors supplying a single motor in a continuous duty application must have an ampacity of at least what percentage of the motor full-load current rating?

In continuous duty applications, conductors supplying a single motor must be sized to ensure that they can handle the motor's full-load current. The National Electrical Code (NEC) requires that the ampacity of the conductors be at least 125% of the motor's full-load current rating. This requirement accounts for potential overload situations that may occur during the motor's operation, ensuring safe and reliable performance without risking overheating or conductor damage.

By specifying 125% as the minimum ampacity, the code provides a buffer for the typical variations in current that a motor may experience, particularly when starting up or under load. This helps to maintain the longevity of the conductors and minimizes the risk of failure. Therefore, the correct answer highlights this important safety practice in the sizing of conductors for motors in continuous duty.