ABB RELION 670 SERIES REG670 - Page 10

T-feeder protection..................................................................... 167
Tertiary reactor protection
..........................................................
171
Restricted earth fault protection (87N)........................................174
Alarm level operation..................................................................176
Generator differential protection GENPDIF (87G)................................ 177
Identification.................................................................................... 177
Application....................................................................................... 177
Setting guidelines............................................................................ 179
General settings......................................................................... 180
Percentage restrained differential operation...............................180
Negative sequence internal/external fault discriminator feature.182
Open CT detection..................................................................... 183
Other additional options..............................................................184
Low impedance restricted earth fault protection REFPDIF (87N).........186
Identification.................................................................................... 186
Application....................................................................................... 186
Transformer winding, solidly grounded.......................................187
Transformer winding, grounded through Zig-Zag grounding
transformer................................................................................. 187
Autotransformer winding, solidly grounded................................ 189
Reactor winding, solidly grounded..............................................189
Multi-breaker applications...........................................................190
CT grounding direction............................................................... 191
Setting guidelines............................................................................ 191
Setting and configuration............................................................191
Settings.......................................................................................192
Section 8 Impedance protection........................................................195
Full-scheme distance measuring, Mho characteristic ZMHPDIS (21).. 195
Identification.................................................................................... 195
Application....................................................................................... 195
Generator underimpedance protection application.....................195
Setting guidelines............................................................................ 195
Configuration.............................................................................. 195
Settings.......................................................................................196
High speed distance protection ZMFPDIS (21).................................... 199
Identification.................................................................................... 199
Application....................................................................................... 200
System grounding.......................................................................200
Fault infeed from remote end..................................................... 203
Table of contents
4 Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062
Application manual