4. Apply the fault condition, including start of CCRBRF, with at least one-phase currentbelow setIP> and residual (earth fault) above setIN>. The current may be arranged byfeeding three- (or two-) phase currents with equal phase angle (I0-component) belowIP>,but of such value that the residual (earth fault) current (3I0) will be above set valueIN>.5. Verify that back-up trip is not achieved.6. Disconnect AC and START input signals.12.5.9.6 Verifying instantaneous back-up trip at CB faulty condition M12104-197 v6Applies in a case where a signal from CB supervision function regarding CB being faulty andunable to trip is connected to input CBFLT.1. Repeat the check of back-up trip time. Disconnect current and START input signals.2. Activate the input CBFLT. The output CBALARM (CB faulty alarm) should appear after settimetCBAlarm. Keep the input activated.3. Apply the fault condition, including start of CCRBRF, with current above set current value.4. Verify that back-up trip is obtained without intentional delay, for example within 20msfrom application of start.12.5.9.7 Verifying the caseRetripMode =Contact M12104-213 v9It is assumed that re-trip without current check is selected,RetripMode =Contact.1. SetFunctionMode =Contact2. Apply input signal for CB closed to relevant input or inputs CBCLDL1, CBCLD2 or CBCDL3.3. Apply the input signal, or signals for the start of CCRBRF.4. Verify that phase selection re-trip and back-up trip are achieved after set times.5. Disconnect the start signal(s). Keep the CB closed signal(s).6. Apply input signal(s), for start of CCRBRF.7.8. Arrange disconnection of CB closed signal(s) well before set back-up trip timet2.9. Verify that back-up trip is not achieved.12.5.9.8 Verifying the function modeCurrent&Contact M12104-237 v5To be made only whenFunctionMode =Current&Contact is selected. It is suggested to makethe tests in one phase only, or at three-phase trip applications for just three-phase tripping.Checking the case with fault current above set valueIP> M12104-241 v6The operation shall be as inFunctionMode =Current.1. SetFunctionMode =Current&Contact.2. Leave the inputs for CB close inactivated. These signals should not influence.3. Apply the fault condition, including the start of CCRBRF, with the current above the setIP> value.4. Check that the re-trip, if selected, and back-up trip commands are achieved.Checking the case with fault current below set valueI>BlkCont M12104-281 v9The case shall simulate a case where the fault current is very low and operation will depend onCB position signal from CB auxiliary contact. It is suggested that re-trip without current checkis used, settingRetripMode =No CBPos Check.1MRK 502 067-UEN B Section 12Testing functionality by secondary injection167Commissioning manual
