4. Apply three-phase currents with their rated value and zero voltages.5. Decrease the measured current in one phase until the DLD1PH signalappears.6. This is the point at which the dead line condition is detected. Check the valueof the decreased current with the set value IDLD< (IDLD< is in percentage ofthe base current IBase).9.7.2.5 Checking the operation of the du/dt and di/dt based function M1405-96 v11Check the operation of the du/dt and di/dt based function if included in the IED.1. Simulate normal operating conditions with the three-phase currents in phasewith their corresponding phase voltages and with all of them equal to theirrated values.2. Change the voltages and currents in all three phases simultaneously.The voltage change must be higher than the set value DU> and the currentchange must be lower than the set value DI<.• The BLKU and BLKZ signals appear without any time delay. TheBLKZ signal will be activated only if the internal deadline detection isnot activated at the same time.• 3PH should appear after 5 seconds, if the remaining voltage levels arelower than the set UDLD< of the dead line detection function.3. Apply normal conditions as in step 1.The BLKU, BLKZ and 3PH signals should reset, if activated, see step 1 and2.4. Change the voltages and currents in all three phases simultaneously.The voltage change must be higher than the set value DU> and the currentchange must be higher than the set value DI<.The BLKU, BLKZ and 3PH signals should not appear.5. Repeat step 2.6. Connect the nominal voltages in all three phases and feed a current below theoperate level in all three phases.7. Keep the current constant. Disconnect the voltage in all three phasessimultaneously.The BLKU, BLKZ and 3PH signals should not appear.8. Change the magnitude of the voltage and current for phase 1 to a value higherthan the set value DU> and DI<.9. Check that the start output signals STDUL1 and STDIL1 and the general startsignals STDU or STDI are activated.10. Check that the start output signals for the current and voltage phases 2 and 3are activated by changing the magnitude of the voltage and current for phases2 and 3.Section 9 1MRK 506 383-UEN ATesting functionality by secondary injection134 Line distance protection REL650 2.2 IECCommissioning manual
