Identification.............................................................................. 165Application................................................................................. 165Setting guidelines...................................................................... 167Section 9 Voltage protection........................................................ 173Two step undervoltage protection UV2PTUV ................................173Identification.............................................................................. 173Application................................................................................. 173Setting guidelines...................................................................... 174Equipment protection, such as for motors and generators...174Disconnected equipment detection...................................... 174Power supply quality ........................................................... 174Voltage instability mitigation................................................. 174Backup protection for power system faults...........................174Settings for two step undervoltage protection...................... 175Two step overvoltage protection OV2PTOV ..................................176Identification.............................................................................. 176Application................................................................................. 177Setting guidelines...................................................................... 177Equipment protection, such as for motors, generators,reactors and transformers.................................................... 178Equipment protection, capacitors......................................... 178Power supply quality............................................................ 178High impedance earthed systems........................................ 178The following settings can be done for the two stepovervoltage protection.......................................................... 178Section 10 Frequency protection....................................................181Underfrequency protection SAPTUF ............................................. 181Identification.............................................................................. 181Application................................................................................. 181Setting guidelines...................................................................... 181Overfrequency protection SAPTOF ...............................................182Identification.............................................................................. 182Application................................................................................. 183Setting guidelines...................................................................... 183Rate-of-change of frequency protection SAPFRC .........................184Identification.............................................................................. 184Application................................................................................. 184Setting guidelines...................................................................... 184Frequency time accumulation protection function FTAQFVR........ 185Identification.............................................................................. 185Application................................................................................. 185Setting guidelines...................................................................... 187Table of contents4 Phasor measurement unit RES670 2.2 IECApplication manual
