ABB RELION 620 Series Technical Manual page 12

Table of contents
6
Non-directional neutral overcurrent protection 51N/50N and
Non-directional ground fault protection 51G/50G............................ 188
Identification............................................................................... 188
Function block............................................................................ 188
Functionality............................................................................... 188
Operation principle..................................................................... 189
Measurement modes..................................................................191
Timer characteristics.................................................................. 191
Application.................................................................................. 193
Signals........................................................................................193
Settings.......................................................................................194
Monitored data............................................................................197
Technical data............................................................................ 198
Directional earth-fault protection 67/51N and 67/50N..................... 198
Identification............................................................................... 198
Function block............................................................................ 199
Functionality............................................................................... 199
Operation principle..................................................................... 199
Directional ground-fault principles.............................................. 204
Measurement modes..................................................................210
Timer characteristics.................................................................. 211
Directional ground-fault characteristics...................................... 212
Application.................................................................................. 223
Signals........................................................................................225
Settings.......................................................................................226
Monitored data............................................................................230
Technical data............................................................................ 231
Sensitive earth-fault protection 50SEF............................................ 232
Identification............................................................................... 232
Function block............................................................................ 232
Functionality............................................................................... 232
Operation principle..................................................................... 233
Measurement modes..................................................................233
Timer characteristics.................................................................. 233
Application.................................................................................. 233
Signals........................................................................................233
Settings.......................................................................................233
Monitored data............................................................................233
Technical data............................................................................ 233
Negative-sequence overcurrent protection 46.................................234
620 series ANSI
Technical Manual