When is it necessary to select a separate overload protective device for a continuous-duty motor?

Selecting a separate overload protective device for a continuous-duty motor is essential to ensure proper protection against overheating and potential damage. This necessity applies regardless of the motor's current rating because continuous-duty motors are designed to run for long periods and can experience thermal buildup. An overload protective device is crucial in these situations, as it helps to interrupt the power supply if the motor draws excessive current, thereby preventing burnout.

While factors like the motor's service factor, local codes, and horsepower ratings may influence specific requirements in certain contexts, the underlying principle is that an overload protection device should always be employed to safeguard all continuous-duty motors. This approach adheres to safety standards and helps in maintaining the longevity and reliability of the motor, ensuring that it operates within its designed parameters. It is a fundamental electrical safety practice that transcends individual specifications or categorizations.