7SR18 Commissioning & Maintenance Guide
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3.8 Undercurrent (37) ............................................................................................................................ 40
3.8.1 Element Blocking ............................................................................................................... 41
3.8.2 Element Blocking from current guard .................................................................................. 41
3.9 Thermal Overload (49) .................................................................................................................... 42
3.9.1 Element Blocking ............................................................................................................... 43
Section 4: Supervision Functions ..................................................................................................................... 44
4.1 CB Fail (50BF) ................................................................................................................................ 44
4.1.1 Element Blocking ............................................................................................................... 45
4.2 Current Transformer Supervision (60CTS) ....................................................................................... 46
4.3 Broken Conductor (46BC) ............................................................................................................... 47
4.3.1 Element Blocking ............................................................................................................... 48
4.4 Trip/Close Circuit Supervision (74T/CCS)........................................................................................ 49
4.5 Magnetising Inrush Detector (81HBL2)............................................................................................ 50
Section 5: Control & Logic Functions ................................................................................................................ 51
5.1 Quick Logic ..................................................................................................................................... 51
Section 6: Testing and Maintenance ................................................................................................................. 52
6.1 Periodic Tests ................................................................................................................................. 52
6.2 Maintenance ................................................................................................................................... 52
6.3 Troubleshooting .............................................................................................................................. 53
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