Which condition is likely if a motor intermittently shuts off?

When a motor intermittently shuts off, one likely condition is frequent resets of the overload protection. Overload protection is designed to monitor the current flowing through the motor and prevent damage due to excessive current draw. If the motor is operating under heavy load or experiencing some mechanical issues, it may cause the current to exceed the set limits, triggering the overload protection mechanism. This results in the motor shutting off to prevent damage.

When this happens repeatedly, it leads to frequent resets of the overload protection, indicating that the motor is not able to operate continuously without interruptions. This behavior can highlight underlying issues such as insufficient motor sizing, mechanical binding, or other factors that cause the motor to draw higher current at times.

The other options do not align with the symptoms of an intermittently shutting off motor. Continuous engagement of holding contacts or a stable power supply would not typically cause intermittent shutdowns, and although a faulty holding contact circuit could lead to erratic operation, it is less directly related to the specific mechanism of overload protection that most often affects the motor in such scenarios.