ELECTRONIC CIRCUIT BREAKER

摘要

Provided is an electronic circuit breaker equipped with a trip device in an electronic circuit and an electromagnetic trip device, such that the electronic circuit breaker can determine that an excess current is flowing in an alternating current electrical circuit and that the current value cannot be correctly measured. The electronic circuit breaker is provided with: a time-limiting circuit (11) that outputs a trip signal for breaking a circuit at an opening and closing contact (2) after a prescribed period of time when the current flowing in an alternating current electrical circuit (1) exceeds a prescribed value; an electronic trip device (3) to which a bias is applied by the trip signal and that breaks the circuit at the opening and closing contact (2); an electromagnetic trip device (4) to which a bias is electromagnetically applied by an excessive current flowing in the alternating current electrical circuit (1) and which breaks the circuit at the opening and closing contact (2) more rapidly than the first trip device (3); and an alarm device (5) that generates an output signal when the circuit is broken at the opening and closing contact point by the electronic trip device (3) or the electromagnetic trip device (4). The output signal of the alarm device (5) is input to the time-limiting circuit (11), which determines whether the measurement of the current value for an incident from an output signal from a current detection means (6) is accurate or not on the basis of the timing of the generation of the alarm device (5) output signal.