Identification.....................................................................................................................................196

7.17.2

Application........................................................................................................................................ 196

7.17.2.1

Base quantities..............................................................................................................................197

7.17.2.2

Application possibilities.............................................................................................................. 197

7.17.2.3

Undervoltage seal-in.....................................................................................................................197

7.17.3

Setting guidelines............................................................................................................................ 198

7.17.3.1

Explanation of the setting parameters.................................................................................... 198

7.17.3.2

Voltage-restrained overcurrent protection for generator and step-up transformer.....199

7.17.3.3

Overcurrent protection with undervoltage seal-in................................................................200

Section 8

Voltage protection.............................................................................................. 201

8.1

Two step undervoltage protection UV2PTUV (27)......................................................................... 201

8.1.1

Identification.....................................................................................................................................201

8.1.2

Application.........................................................................................................................................201

8.1.3

Setting guidelines............................................................................................................................202

8.1.3.1

Equipment protection, such as for motors and generators................................................202

8.1.3.2

Disconnected equipment detection......................................................................................... 202

8.1.3.3

Power supply quality ................................................................................................................... 202

8.1.3.4

Voltage instability mitigation.................................................................................................... 202

8.1.3.5

Backup protection for power system faults........................................................................... 202

8.1.3.6

Settings for Two step undervoltage protection.................................................................... 202

8.2

Two step overvoltage protection OV2PTOV (59).......................................................................... 204

8.2.1

Identification.................................................................................................................................... 204

8.2.2

Application........................................................................................................................................ 204

8.2.3

Setting guidelines............................................................................................................................205

8.2.3.1

Equipment protection, such as for motors, generators, reactors and transformers....205

8.2.3.2

Equipment protection, capacitors............................................................................................206

8.2.3.3

Power supply quality....................................................................................................................206

8.2.3.4

High impedance grounded systems.........................................................................................206

8.2.3.5

The following settings can be done for the two step overvoltage protection................206

8.3

Two step residual overvoltage protection ROV2PTOV (59N)......................................................208

8.3.1

Identification.................................................................................................................................... 208

8.3.2

Application........................................................................................................................................ 208

8.3.3

Setting guidelines............................................................................................................................208

8.3.3.1

Equipment protection, such as for motors, generators, reactors and transformers....209

8.3.3.2

Equipment protection, capacitors............................................................................................209

8.3.3.3

Power supply quality....................................................................................................................209

8.3.3.4

High impedance grounded systems.........................................................................................209

8.3.3.5

Direct grounded system..............................................................................................................210