What device is designed to protect a motor against overheating due to overload?

• A. Watertight
• B. Thermal Protector
• C. Ungrounded
• D. Service

Answer: (B)

A thermal protector is specifically designed to safeguard motors from overheating caused by overload conditions. When a motor operates beyond its rated capacity, the thermal protector senses the increase in temperature and interrupts the power supply to the motor, preventing potential damage from overheating. This is essential in maintaining the longevity and efficiency of electrical appliances, as excessive heat can lead to insulation breakdown and motor failure.

In contrast, the other options do not assume the role of protecting against overheating specifically due to overload situations. A watertight device pertains to environmental protection against water ingress, which is unrelated to motor protection. An ungrounded device refers to electrical systems lacking a ground connection, which does not inherently address overheating issues. A service device typically relates to the overall supply or management of electrical systems rather than providing specific protective functions for individual motors. Therefore, the thermal protector is the most appropriate choice for preventing motor damage from overheating caused by overload conditions.