5. Check the operating time by injecting a voltage corresponding to 1.2 ˣU>Trip level. Make note of the measured trip time.6. If required, verify the trip time at another voltage. Normally 2 ˣ U>Trip isselected.7. If used, measure the alarm level operating value. Increase the voltage andmake note of the operate value U>Alarm. This is done with manual test andwithout trip of the test set.8. Measure the operating time on the alarm output by connecting the stop of thetest set to an output from tAlarm. Inject a voltage 1.2 ˣ U>Alarm and measurethe alarm time.9. Check that trip and alarm outputs operate according to the configurationlogic.10. Finally check that start and alarm information is stored in the event menu andif a serial connection to the SA is available verify that the correct and only therequired signals are presented on the local HMI and on the SCADA system.Information on how to use the event menu is found in the operator'smanual.11.3.1.2 Completing the test SEMOD55257-73 v4Continue to test another function or end the test by changing the TESTMODEsetting to Off. Restore connections and settings to their original values, if they werechanged for testing purposes.11.3.2 Restricted earth fault protection, low impedance REFPDIFSEMOD55252-82 v8Prepare the IED for verification of settings outlined in Section "Preparing the IEDto verify settings".11.3.2.1 Verifying the settings SEMOD55252-86 v111. Connect the test set for single-phase current injection to the protectionterminals connected to the CT in the power transformer neutral-to-earthcircuit.2. Increase the injection current and note the operating value of the protectionfunction.3. Check that all trip and start signals appear according to the configurationlogic.4. Decrease the current slowly from operate value and note the reset value.5. Connect the timer and set the current to ten times the value of the IdMinsetting.6. Switch on the current and note the operate time.Section 11 1MRK 505 378-UEN ATesting functionality by secondary injection106 Line differential protection RED670 2.2 IECCommissioning manual
