If No CBPos Check or Retrip off is set, only back-up trip can beused to check set IP>.10.4.6.2 Checking the residual (earth fault) current operate valueIN> setbelowIP> M12104-80 v9Check the low set IN> current where setting FunctionMode = Current and settingBuTripMode = 1 out of 41. Apply the fault condition, including START of CCRBRF, with a current justbelow set IN>.2. Repeat the fault condition and increase the current in steps until trip appears.3. Compare the result with the set IN>.4. Disconnect AC and START input signals.10.4.6.3 Checking the re-trip and back-up times M12104-93 v11The check of the set times can be made in connection with the check of operatevalues above.Choose the applicable function and trip mode, such as FunctionMode = Currentand RetripMode = CB Pos Check .1. Apply the fault condition, including start of CCRBRF, well above the setcurrent value. Measure the time from START of CCRBRF.2. Check the re-trip t1 and back-up trip times t2 and t3.In applicable cases, the back-up trip for multi-phase start t2MPh and back-uptrip 2, t2 and t3 can also be checked. To check t2MPh, a two-phase or three-phase start shall be applied.10.4.6.4 Verifying the re-trip mode M12104-36 v6Choose the mode below, which corresponds to the actual case.In the cases below it is assumed that FunctionMode = Current is selected.Checking the case without re-trip,RetripMode =Retrip Off M12104-107 v71. Set RetripMode = Retrip Off.2. Apply the fault condition, including start of CCRBRF, well above the setcurrent value.3. Verify that no re-trip, but back-up trip is achieved after set time.Checking the re-trip with current check,RetripMode =CB Pos CheckM12104-48 v71MRK 505 372-UEN A Section 10Testing functionality by secondary injectionBusbar protection REB670 2.2 IEC 97Commissioning manual
