should be checked that the event and alarm signalling is correct by activating theevents and performing some selected tests.15.2.2.5 Self supervision check SEMOD56528-23 v5Once secondary testing has been completed, it should be checked that no self-supervision signals are activated continuously or sporadically. Especially check thetime synchronization system, GPS or other, and communication signals, both stationcommunication and remote communication.15.2.2.6 Trip circuit check SEMOD56528-26 v5When the protection IED undergoes an operational check, a tripping pulse is normallyobtained on one or more of the output contacts and preferably on the test switch. Thehealthy circuit is of utmost importance for the protection operation. If the circuit is notprovided with a continuous trip-circuit supervision, it is possible to check that circuit isreally closed when the test-plug handle has been removed by using a high-ohmicvoltmeter and measuring between the plus and the trip output on the panel. Themeasurement is then done through the trip coil of the circuit breaker and therefore thecomplete trip circuit is checked.Note that the breaker must be closed.Please observe that the test system does not provide built-in securityduring this test. If the instrument should be set on Amp instead of Volts,the circuit breaker naturally is tripped, therefore, great care isnecessary.Trip circuit from trip IEDs to circuit breaker is often supervised by trip-circuitsupervision. It can then be checked that a circuit is healthy by opening tripping outputterminals in the cubicle. When the terminal is opened, an alarm shall be achieved onthe signal system after a delay of some seconds.Remember to close the circuit directly after the test and tighten theterminal carefully.Section 15 1MRK 502 073-UUS ACommissioning and maintenance of the fault clearing system294 Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062Commissioning manual
