| 摘要 |
PURPOSE: To obtain a digital protective relay in which the function of relay operating sections can be checked individually by commanding a test input means to output a test signal when a switching is made to a state for testing a desired relay element and interrupting the signal line from desired relay element to a trip signal output means. CONSTITUTION: An input mode selection circuit 4 for switching the data input to each relay operating section 2a-2c between an input converting section 1 and a test section 6 is inserted between the input converting section 1 and the relay operating section 2a-2c. When an element selecting section 7 at the test section 6 is switched to test mode in order to switch the input state of a desired relay operating section 2a among the plurality of relay operating sections 2a-2c, a switch 4a is turned to the test section 6 side by a control signal from the element selecting section 7 thus bringing about a test mode. At the same time, the element selecting section 7 opens the working contact 5a for the relay operating section 2a thus blocking delivery of an abnormal signal to the outside. |
