What function does an overload relay serve?

An overload relay plays a critical role in protecting motors from overheating, which can lead to significant damage or failure. Its primary function is to monitor the current that the motor draws during operation. If the current exceeds a predetermined limit for an extended period, indicating that the motor is under excessive load and at risk of overheating, the overload relay will disconnect power to the motor. This disconnection prevents overheating and potential thermal damage, maintaining the motor's integrity and extending its operational lifespan.

Understanding this function is essential in motor control systems, as overheating can result from various factors, such as mechanical binding, excessive load, or electrical issues. The overload relay acts as a safeguard, ensuring that the motor operates within safe parameters and reducing the chances of costly repairs or replacements due to overheating damage.