What common issue might a single-phase motor experience when overloaded?

When a single-phase motor is overloaded, it is susceptible to excessive heating. This condition arises because as the motor draws more current than its rated capacity to meet the demands of the load, the electrical resistance in the motor's windings generates extra heat. If the heat generated exceeds the motor's ability to dissipate it, the temperature within the motor rises, which can lead to insulation breakdown, reduced lifespan, and potential failure of the motor.

In contrast, increased efficiency is not a result of overload; an overloaded motor typically operates inefficiently. While reduced rotational speed can occur under overload conditions, it is not the primary concern as the excessive heating poses a more immediate risk to the motor. Enhanced torque is also not associated with overload, as the motor's ability to deliver torque is compromised due to overheating and potential mechanical stress. Thus, excessive heating stands out as the primary issue encountered by single-phase motors under overloaded conditions.