What does an overload relay typically monitor in motor operation?

An overload relay is a safety device used in electrical circuits, particularly in motors, to prevent damage from excessive current flow. It primarily monitors the current levels flowing through the motor. When a motor operates normally, it draws a specific amount of current. However, if there is a mechanical failure, jam, or overload condition, the motor may draw more current than it is designed to handle.

The overload relay detects this high current situation, and once it exceeds a predetermined limit, the relay will trip and disconnect the power supply to the motor. This action protects the motor from overheating and potential damage that could occur as a result of prolonged high current flow.

While voltage fluctuations, temperature changes, and air flow can affect a motor's operation, the primary function of an overload relay is focused on monitoring and responding to current levels to ensure safe motor operation and prevent failures.