Earth leakage circuit breaker

An earth leakage circuit breaker comprising:

• a leakage current detection unit for outputting a leakage current detection signal according to a leakage current from a circuit;
• a conversion unit for outputting a leakage current magnitude of a fundamental wave component, a ratio of a third harmonic component, and a ratio of a positive pole peak current value to a negative pole peak current value, on a basis of the leakage current detection signal outputted from the leakage current detection unit;
• and
• a control unit for comparing the leakage current magnitude of a fundamental wave component, the ratio of a third harmonic component, and the ratio of a positive pole peak current value to a negative pole peak current value, outputted by the conversion unit, with predetermined reference values to determine whether or not a leakage current of an alternating current (AC) component is generated or a leakage current of a direct current (DC) component is generated and to thereby output a trip control signal when it is determined that the leakage current of the DC component or the AC component is generated,
• wherein the control unit is further configured to:
• when the leakage current is detected, detect whether a current of the circuit is in a balanced current state that is distinguished from the leakage current of the AC component and the leakage current of the DC component, based on the leakage current magnitude of the fundamental wave component, the ratio of the third harmonic component, and the ratio of the positive pole peak current value to the negative pole peak current value, and
• restrict output of the trip control signal when the current of the circuit is in the balanced current state.