
9.1.3 Setting guidelines.................................................................................................................. 149
9.1.3.1 Equipment protection, such as for motors and generators....................................150
9.1.3.2 Disconnected equipment detection............................................................................. 150
9.1.3.3 Power supply quality .......................................................................................................150
9.1.3.4 Voltage instability mitigation........................................................................................ 150
9.1.3.5 Backup protection for power system faults............................................................... 150
9.1.3.6 Settings for Two step undervoltage protection........................................................ 150
9.2 Two step overvoltage protection OV2PTOV .......................................................................151
9.2.1 Identification........................................................................................................................... 151
9.2.2 Application...............................................................................................................................152
9.2.3 Setting guidelines.................................................................................................................. 152
9.3 Two step residual overvoltage protection ROV2PTOV..................................................... 154
9.3.1 Identification...........................................................................................................................154
9.3.2 Application...............................................................................................................................154
9.3.3 Setting guidelines.................................................................................................................. 154
9.3.3.1 Equipment protection, such as for motors, generators, reactors and
transformers......................................................................................................................155
9.3.3.2 Power supply quality........................................................................................................ 155
9.3.3.3 High impedance earthed systems.................................................................................155
9.3.3.4 Direct earthed system..................................................................................................... 156
9.3.3.5 Settings for Two step residual overvoltage protection............................................157
9.4 Overexcitation protection OEXPVPH................................................................................... 158
9.4.1 Identification...........................................................................................................................158
9.4.2 Application...............................................................................................................................158
9.4.3 Setting guidelines.................................................................................................................. 159
9.4.3.1 Recommendations for input and output signals....................................................... 159
9.4.3.2 Settings...............................................................................................................................159
9.4.3.3 Service value report..........................................................................................................160
Section 10 Frequency protection.................................................................................161
10.1 Under frequency protection SAPTUF....................................................................................161
10.1.1 Identification........................................................................................................................... 161
10.1.2 Application............................................................................................................................... 161
10.1.3 Setting guidelines...................................................................................................................161
10.2 Over frequency protection SAPTOF......................................................................................162
10.2.1 Identification...........................................................................................................................162
10.2.2 Application...............................................................................................................................162
10.2.3 Setting guidelines.................................................................................................................. 162
10.3 Rate-of-change frequency protection SAPFRC.................................................................. 163
10.3.1 Identification...........................................................................................................................163
10.3.2 Application...............................................................................................................................163
10.3.3 Setting guidelines.................................................................................................................. 164
Section 11 Secondary system supervision.................................................................165
11.1 Breaker close/trip circuit monitoring TCSSCBR................................................................ 165
11.1.1 Identification...........................................................................................................................165
11.1.2 Application...............................................................................................................................165
Table of contents
Transformer protection RET650 5
Application manual
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