GROUNDED CIRCUIT, EARTH LEAKAGE DETECTOR, AND EARTH LEAKAGE BREAKER

摘要

The purpose of the present invention is to achieve a safe grounded circuit which can be released from a grounded state without interrupting a load even if earth leakage occurs. An earth leakage detector monitors the voltage at both ends of a first resistance element and the voltage at both ends of a second resistance element. When the earth leakage detector detects that a deviation in the ratio or difference between the voltage at both ends of the first resistance element and the voltage at both ends of the second resistance element is equal to or above a prescribed value from the value of the ratio or difference between the voltage at both ends of the first resistance element and the voltage at both ends of the second resistance element when earth leakage has not occurred, a switch is set to a non-conduction state. Furthermore, when the earth leakage has subsided the switch is set to a conduction state.