| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect electric leakage caused by a tracking phenomenon by simple processing.SOLUTION: A leakage detection unit 107 determines occurrence of a leakage caused by a tracking phenomenon if a first index value exceeds a first threshold, the first index value being based on current values sampled in a first period having a length corresponding to a period of an AC current and current values sampled in a second period prior to the first period by as much as the period of the AC current, if a second index value exceeds a second threshold, the second index value being based on current values sampled in a first half period of the first period and current values sampled in a second half period of the first period, if a third index value exceeds a third threshold, the third index value being based on the current values sampled in the first period and current values sampled in a third period prior to the second period by as much as a natural number multiple of the period of the AC current. |
