What is the primary function of overload protectors installed in a motor starter?

The primary function of overload protectors installed in a motor starter is to protect motors against overload. When a motor experiences an overload, it draws more current than it is designed to handle, which can lead to overheating and potential damage to the motor windings. The overload protector detects this excess current and interrupts the electrical supply to the motor, preventing damage by stopping the motor before it can overheat and fail.

This protection is crucial for the longevity and reliability of electric motors, as sustained overload conditions can significantly reduce a motor's lifespan. By tripping during overload situations, the protector helps ensure that the motor operates within its safe limits and maintains its operational integrity.

While protecting personnel, improving motor efficiency, and increasing motor speed are important considerations in motor applications, these functions do not relate directly to the specific role of overload protectors. Therefore, the focus on the protection of the motor against overload makes this answer the most accurate choice.