| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect an operation abnormality of a movable contact.SOLUTION: An operation abnormality of a movable contact (9) with respect to a fixed contact (10) is detected on the basis of at least one of a separation transient response signal of a coil current in an excitation coil (6) when a separation pulse signal is supplied, and an attraction transient response signal of the coil current when, in a state where an attraction signal is supplied, an attraction pulse signal is supplied. |
