A Current Overload Relay is an electrical protection device used to detect abnormal currents in an electrical circuit, primarily for preventing motors and other machinery from damage due to overcurrent conditions. It functions by monitoring the current flowing through a motor or electrical system and disconnecting the circuit when the current exceeds preset limits, thereby protecting the equipment from overheating, insulation damage, or other failures.

    Working Principle

    The relay operates by continuously monitoring the current in a circuit. When the current exceeds a specific threshold—usually a multiple of the rated current of the motor or equipment—the relay is triggered. There are two main approaches for detecting this overload：