CHAPTER 8: APPLICATION OF SETTINGS SETTINGSG60 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL 8-98Set the zone 3 reach at 120% of the generator transient reactance. Compare the time delay of this element to thegenerator decrement curve to verify the adequacy of this setting.Eq. 8-28Eq. 8-29An mho shape has been chosen for this example. Therefore, the quadrilateral settings are left at their default values. Makethe following changes in the EnerVista software or the front panel SETTINGS GROUPED ELEMENTS SETTING GROUP 1 DISTANCE PHASE DISTANCE Z1(3) menus.8.2.10 Stator ground fault8.2.10.1 Auxiliary overvoltageStator ground fault protection is implemented with an overvoltage element connected at the generator neutral resistor.The auxiliary overvoltage element is used in this example. The auxiliary voltage input has been assigned previously to theNEUTRL source. In this example, the element is set to protect 97% of the stator against ground faults.Eq. 8-30Set the time delay longer than the longest normal clearing time for faults outside the generator zone. If the phase VTs arewye-connected, then also coordinate this element with VT secondary fuses to prevent false operations for VT secondaryground faults. For the sample system, a time delay of 1 second is to be used. Make the following changes in the EnerVistasoftware or the front panel SETTINGS GROUPED ELEMENTS SETTING GROUP 1 VOLTAGE ELEMENTS AUXILIARY OV1menu.
