OVERLOAD PREVENTION DEVICE USING RELAY, AND SYSTEM AND METHOD FOR PROTECTING MOTOR USING THEREOF

摘要

PURPOSE: An overload preventing device using a relay, a motor protecting system using the same, and a motor protecting method are provided to improve the stability and reliability of a system by continuously sensing a load current to prevent the overload. CONSTITUTION: A current sensor(610) senses a load current flowing from a power supply source to a load. A first relay unit(640) interrupts power from the power supply source to the load. A second relay unit(650) interrupts power from the power supply source to the load again. The second relay unit transmits an operation signal to a shunt coil(450) of a circuit breaker unit. A time counter unit(620) counts time by using the timer.