Patent ID: 7746617

Claim:
An overload relay that trips a current flow between a power source and a load, the overload relay comprising: a trip capacitor that stores therein an electric charge as a trip charge; a reset capacitor that stores therein an electric charge as a reset charge; a trip coil that is configured to be excited by the trip charge so as to trip the current flow; a reset coil that is configured to be excited by the reset charge so as to reset tripped current flow; an energizing unit that energizes the trip coil by using the trip charge, and energizes the reset coil by using the reset charge; a capacitor-diagnosing unit that diagnoses whether there is degradation of a property of the trip capacitor; and a display unit that displays result of diagnosis made by the capacitor-diagnosing unit; wherein the energizing unit forcibly energizes the trip coil when the capacitor-diagnosing unit diagnoses that there is degradation of the property of the trip capacitor.