What is the function of an overload relay?

The function of an overload relay is primarily to protect motors from overheating due to excessive current flow. When a motor operates under normal conditions, it draws a specific amount of current. However, if the motor becomes overloaded—due to mechanical issues, blockages, or prolonged operation at high loads—the current can exceed the motor's rated capacity.

The overload relay monitors the current flowing to the motor and, when it detects that the current exceeds a certain threshold for a specified duration, it will open the circuit. This action breaks the electrical connection and stops current flow, thereby preventing the motor from overheating and sustaining damage. Overload relays are essential components in motor protection systems, ensuring that equipment operates safely and effectively without risk of failure due to excessive heat generated by overcurrent situations.

This understanding is crucial in electrical installations, as proper utilization of overload relays is central to maintaining the longevity and reliability of motor systems within various applications.