TIME LIMIT MEASURING METHOD FOR OVERCURRENT RELAY

摘要

PROBLEM TO BE SOLVED: To easily shorten work time and prevent connection errors in unit testing of an overcurrent relay.SOLUTION: In the time limit measuring method of the overcurrent relay 1, a relay testing device 3 is connected to an overcurrent relay 1 and a breaker 2 which are installed in substation facilities, the overcurrent relay 1 is relay-operated by a test current supplied from the relay testing device 3, and a trip operation of the breaker 2 based on a relay operation of the overcurrent relay 1 is detected and a linkage time limit of the overcurrent relay 1 and the breaker 2 from an input of the test current to the trip operation is measured. A clamp-type current transformer 24 is detachably installed in wiring 8 to which the overcurrent relay 1 and the breaker 2 are connected. Thus, the relay operation of the overcurrent relay 1 is detected and the unit time limit of the overcurrent relay 1 from the input of the test current to the relay operation can be measured.