How do thermally protected motors prevent overheating?

Thermally protected motors are designed to prevent overheating primarily through the use of a built-in overload device. This device monitors the temperature of the motor during operation. When the temperature exceeds a predetermined threshold, the device acts to cut off power to the motor, effectively preventing damage that can occur from excessive heat. This automatic protection mechanism is crucial because it responds to unsafe conditions without requiring manual intervention, ensuring the longevity and safe operation of the motor.

While external cooling fans and regular maintenance service can contribute to a motor's overall efficiency and factory performance, they do not provide the specialized thermal protection that an overload device does. A larger motor size may also help in some cases, but it does not directly address the specific issue of overheating protection. Thus, the built-in overload device is the most effective and relevant method for preventing motor overheating in thermally protected motors.