| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital protector and controller that can readily find defects in an automatic checking circuit and timely, without an inspection tour by a maintenance worker and contributes to improvement in operation reliability, by enhancing the operation accuracy of the automatic checking circuit.SOLUTION: An on-delay timer 11 is set to a time T2 slightly longer than a checking period T1, preliminarily set in the automatic checking circuit 1. When a checking execution and finish signal 5 is not generated in the automatic checking circuit 1, even if the time T2 arrives and passes, the on-delay timer 11 is counted up, so that an alarm 12 indicating inexecution of automatic checking is output. When a pulse counter 13 counts the checking execution finish signal 5 twice within the checking period T1, it issues a high-frequency alarm 14. |
