Siemens SIPROTEC 7SJ80

2.2 Overcurrent Protection 50, 51, 50N, 51N.......................................................................... 56
2.2.1 General ...................................................................................................................... 56
2.2.2 Definite Time, High-set Elements 50-3, 50-2, 50N-3, 50N-2..........................................57
2.2.3 Definite Time Overcurrent Elements 50-1, 50N-1......................................................... 59
2.2.4 Inverse Time Overcurrent Elements 51, 51N ................................................................62
2.2.5 Inverse Time Overcurrent Protection 51V (Voltage-controlled / Voltagerestraint)...........65
2.2.6 Dynamic Cold Load Pickup Function.............................................................................67
2.2.7 Inrush Restraint .......................................................................................................... 68
2.2.8 Pickup Logic and Tripping Logic................................................................................... 69
2.2.9 Two-phase Overcurrent Protection (Only Non-Directional) ...........................................70
2.2.10 Fast Busbar Protection Using Reverse Interlocking ....................................................... 71
2.2.11 Setting Notes...............................................................................................................72
2.2.12 Settings.......................................................................................................................77
2.2.13 Information List...........................................................................................................79
2.3 Directional Overcurrent Protection 67, 67N....................................................................... 82
2.3.1 General....................................................................................................................... 82
2.3.2 Definite Time Directional High-set Elements 67-2, 67N-2, 67-3, 67N-3......................... 84
2.3.3 Definite Time, Directional Time Overcurrent Elements 67-1, 67N-1...............................85
2.3.4 Inverse Time, Directional Overcurrent Elements 67-TOC, 67N-TOC............................... 88
2.3.5 Interaction with Fuse Failure Monitor (FFM).................................................................89
2.3.6 Dynamic Cold Load Pickup Function.............................................................................90
2.3.7 Inrush Restraint........................................................................................................... 90
2.3.8 Determination of Direction.......................................................................................... 90
2.3.9 Reverse Interlocking for Double End Fed Lines..............................................................94
2.3.10 Setting Notes...............................................................................................................95
2.3.11 Settings.....................................................................................................................101
2.3.12 Information List.........................................................................................................104
2.4 Dynamic Cold Load Pickup...............................................................................................106
2.4.1 Functional Description...............................................................................................106
2.4.2 Setting Notes.............................................................................................................108
2.4.3 Settings.....................................................................................................................109
2.4.4 Information List.........................................................................................................111
2.5 Single-Phase Overcurrent Protection................................................................................112
2.5.1 Functional Description...............................................................................................112
2.5.2 High-impedance Ground Fault Unit Protection........................................................... 113
2.5.3 Tank Leakage Protection............................................................................................115
2.5.4 Setting Notes.............................................................................................................116
2.5.5 Settings.....................................................................................................................121
2.5.6 Information List.........................................................................................................121
2.6 Voltage Protection 27, 59................................................................................................122
2.6.1 Measurement Principle.............................................................................................. 122
2.6.2 Overvoltage Protection 59......................................................................................... 123
2.6.3 Undervoltage Protection 27....................................................................................... 124
2.6.4 Setting Notes.............................................................................................................127
2.6.5 Settings.....................................................................................................................130
2.6.6 Information List.........................................................................................................131
Table of Contents
12 SIPROTEC 4, 7SJ80, Manual
E50417-G1140-C343-A8, Edition 12.2017