10.4.7.4 Verifying the back-up trip mode SEMOD128582-115 v2In the cases below it is assumed that FunctionMode = Current is selected.Checking that back-up tripping is not achieved at normal CB trippingSEMOD128582-119 v4Use the actual tripping modes. The case below applies to re-trip with current check.Procedure1. Apply the fault condition, including START of CCSRBRF, with phase currentwell above set value IP>.2. Arrange switching the current off, with a margin before back-up trip time, t2.It may be made at issue of re-trip command.3. Check that re-trip is achieved, if selected, but no back-up trip.4. Disconnect AC and start input signals.10.4.7.5 Verifying instantaneous back-up trip at “CB faulty” condition SEMOD128582-167 v4Applies in a case where signal “CB faulty and unable to trip” is connected to inputCBFLT.Procedure1. Repeat the check of back-up trip time. Disconnect current and START inputsignals.2. Activate the input CBFLT. The output CBALARM (CB faulty alarm) shouldappear after set time tCBAlarm. Keep the input activated.3. Apply the fault condition, including START of CCSRBRF, with currentabove set current value.4. Verify that back-up trip is obtained without intentional delay, for example,within 20ms from application of START.5. Disconnect injected AC and input signals.10.4.7.6 Verifying the caseFunctionMode =Contact SEMOD128582-183 v4It is assumed that re-trip without current check is selected, RetripMode = NoCBPos Check.Procedure1. Set FunctionMode = Contact.2. Apply input signal for CB closed to relevant input or inputs CBCLD3. Apply input signal, or signals for START of CCSRBRF. The value of currentcould be low.4. Verify that re-trip and back-up trip are achieved after set times.5. Disconnect the START signal(s). Keep the CB closed signal(s).1MRK 505 372-UEN A Section 10Testing functionality by secondary injectionBusbar protection REB670 2.2 IEC 103Commissioning manual
