| 摘要 |
PURPOSE:To execute a cutoff operation without generating a reignition by outputting a pullout command at an appropriate time point calculated on the basis of the detected value of an AC current at a zero phase point, the contact parting time and the arc time of a circuit breaker and the operating time of an electric circuit. CONSTITUTION:A sampling processing is executed via a sampling circuit 53, where whether a circuit breaker pullout command is present is judged. When the pullout command is present, sampling data are read and a phase zero point and a frequency are detected. Then, a time Ttr is calculated. When the time Ttr is obtained, whether the present time point is a command time point is judged by comparing with the time Ttr. When the present time point is the command time point, whether a target circuit breaker 3 is in a closed condition is judged. Thus, by outputting the pullout command so as to conduct a contact parting at an appropriate phase point, a circuit breaker operation can be executed without generating a reignition. |
