12.7.3 Rate-of-change frequency protection SAPFRC M16256-2 v6Prepare the IED for verification of settings as outlined in section "Requirements" andsection "Preparing for test" in this chapter.12.7.3.1 Verifying the settings M16256-8 v1Verification of START value and time delay to operate M16256-10 v51. Check that the settings in the IED are appropriate, especially the START value and thedefinite time delay. SetStartFreqGrad, to a rather small negative value.2. Supply the IED with three-phase voltages at their rated values.3. Slowly decrease the frequency of the applied voltage, with an increasing rate-of-changethat finally exceeds the setting ofStartFreqGrad, and check that the START signalappears.4. Note the operate value and compare it with the set value.5. Increase the frequency to rated operating conditions, and zero rate-of-change.6. Check that the START signal resets.7. Instantaneously decrease the frequency of the applied voltage to a value about 20%lower than the nominal value.8. Measure the time delay for the TRIP signal, and compare it with the set value.Extended testing M16256-29 v41. The test above can be repeated to check a positive setting ofStartFreqGrad.2. The tests above can be repeated to check the time to reset.3. The tests above can be repeated to test the RESTORE signal, when the frequencyrecovers from a low value.12.7.3.2 Completing the test M16256-39 v4Continue to test another function or end the test by changing theTestMode setting toOff.Restore connections and settings to their original values, if they were changed for testingpurposes.12.7.4 Frequency time accumulation protection function FTAQFVRGUID-F7BD8E10-EF88-4698-87F4-0D4365004705 v2Prepare the IED for verification of settings as outlined in section “Overview” and section“Preparing for test” in this chapter.12.7.4.1 Verifying the settings GUID-864636E0-6399-44E1-BD2C-C2113FB78C61 v3Time measurement and the injection of current and voltage can be done using a common testequipment.Verification of the START value and time delay to operation1. Connect the test set for the injection of three-phase currents and three-phase voltages tothe appropriate current and voltage terminals of the IED.2. Ensure that the settings in the IED are appropriate, especially theCurrStartLevel,FreqHighLimit,FreqLowLimit,UHighLimit andULowLimit setting.3. Supply the IED with three-phase currents and voltages at their rated value.4. Slowly decrease the frequency of the applied voltage until it crosses the frequency highlimit and the START signal appears.5. Check that the FREQOK signal appears.1MRK 502 067-UEN B Section 12Testing functionality by secondary injection195Commissioning manual
