| 摘要 |
PURPOSE:To prevent damages to a protective relay and a tester by limiting the measurement of operation time of a relay to a fixed time. CONSTITUTION:When a current for testing of a tester 2 is applied to a terminal 40, a protective relay 1 operates normally. But when a current value exceeds a fixed setting, a relay 26 operates and a contact part 28 is turned ON to apply a working signal to the tester 2 through a connector 30 for testing and a cable 64 for checking a contact. The tester 2 has a setting part 12 in which limit time predetermined is set for the measurement of instantaneous working time and time limited working time. When the relay 1 does not operate even after the limit time passes, an error message is displayed while the supply of the current for testing is stopped. This prevents damages to the relay 1 and the tester 2, otherwise caused by the continued supply of the quantity of electricity for testing to the protective relay for a long time. |
