What is a common sign that a motor has experienced overheating?

When a motor experiences overheating, one of the most common protective mechanisms that activates is the tripping of overload relays. Overload relays are designed to monitor the current flowing to the motor. If the motor overheats, it often draws excessive current, leading the overload relay to trip and disconnect the power supply to prevent further damage. This safety feature helps protect the motor from potential failure due to overheating, which can lead to insulation breakdown and other severe damage.

In contrast, while increased noise levels, unusual vibrations, and excessive speed fluctuations can indicate problems with a motor, they are not direct signs of overheating. They may be symptoms of mechanical issues or other electrical problems, but they do not specifically indicate that the motor has reached a temperature that would trigger protection mechanisms like an overload relay.