4. Verify that phase selection re-trip (if selected) and back-up trip are achievedafter set times. Failure to trip is simulated by keeping the signal(s) CB closedactivated.5. Disconnect the input signal and the START signal(s). Keep the CB closedsignal(s).6. Apply the fault and the start again. The value of current should be below theset value I>BlkCont.7. Arrange disconnection of BC closed signal(s) well before set back-up triptime t2. It simulates a correct CB tripping.8. Verify that back-up trip is not achieved. Re-trip can appear for example, dueto selection “Re-trip without current check”.11.5.7.8 Completing the test M12104-72 v5Continue 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.11.5.8 Stub protection STBPTOC M14922-2 v7Prepare the IED for verification of settings outlined in Section "Preparing the IEDto verify settings".Logical signals for STBPTOC protection are available on the local HMIunderMain menu/Settings/Setting group N/Current protection/Stub(PTOC,50STB)/STBPTOC:x11.5.8.1 Measuring the operate limit of set values M14922-6 v81. Check that the input logical signals BLOCK and RELEASE and the outputlogical signal TRIP are all logical zero.2. Activate the input RELEASE on the STBPTOC function block3. For a short while inject a current (fault current) in one phase to about 110% ofthe set operating current, and switch the current off.Observe to not exceed the maximum permitted overloading of the currentcircuits in the IED.4. Switch the fault current on and measure the operating time of STBPTOC.Use the TRIP signal from the configured binary output to stop the timer. Theoperation should be instantaneously.5. Activate the input BLOCK on the STBPTOC function block.6. Switch on the fault current (110% of the setting).No TRIP signal should appear.7. Switch off the fault current.8. For a short while inject a current (fault current) in same phase to about 90%of the set operating current, and switch the current off.9. Switch the fault current on.1MRK 505 378-UEN A Section 11Testing functionality by secondary injectionLine differential protection RED670 2.2 IEC 187Commissioning manual
