Application....................................................................................... 151
Setting guidelines............................................................................ 152
Equipment protection, such as for motors and generators.........152
Disconnected equipment detection............................................ 152
Power supply quality ..................................................................152
Voltage instability mitigation....................................................... 153
Backup protection for power system faults.................................153
Settings for Two step undervoltage protection........................... 153
Two step overvoltage protection OV2PTOV (59)................................. 154
Identification.................................................................................... 154
Application....................................................................................... 155
Setting guidelines............................................................................ 155
Two step residual overvoltage protection ROV2PTOV (59N)...............158
Identification.................................................................................... 158
Application....................................................................................... 158
Setting guidelines............................................................................ 158
Power supply quality...................................................................159
High impedance grounded systems........................................... 159
Direct grounded system..............................................................160
Settings for Two step residual overvoltage protection................161
Loss of voltage check LOVPTUV (27).................................................. 163
Identification.................................................................................... 163
Application....................................................................................... 163
Setting guidelines............................................................................ 163
Advanced users settings................................................................. 163
Section 8 Frequency protection.........................................................165
Underfrequency protection SAPTUF (81).............................................165
Identification.................................................................................... 165
Application....................................................................................... 165
Setting guidelines............................................................................ 166
Overfrequency protection SAPTOF (81)...............................................166
Identification.................................................................................... 167
Application....................................................................................... 167
Setting guidelines............................................................................ 167
Rate-of-change frequency protection SAPFRC (81)............................ 168
Identification.................................................................................... 168
Application....................................................................................... 168
Setting guidelines............................................................................ 169
Section 9 Secondary system supervision..........................................171
Table of contents
5
Application manual