Backup Distance - GE G60 Instruction Manual

SETTINGS
Since this element coordinates with system protections, a timed reset is chosen. The element must be blocked for a VT fuse
failure. The neutral source is chosen. Make the following changes in the EnerVista software or the front panel
GROUPED ELEMENTS  SETTING GROUP 1  PHASE CURRENT  PHASE TOC1

8.2.9 Backup distance

This function provides time-delayed protection for system faults that have not been cleared by system protections and
provides backup protection for stator faults.
The "Line" source is used in this example to permit the application of a forward and reverse zone. The memory duration is
to be left at the default setting (10 cycles).
Zone 1 looks forward and covers the generator step-up (GSU) transformer and the transmission line leaving the station.
Zone 3 looks in the reverse direction and covers the stator winding. Zone 2 is not used in this example. Both the VTs and the
CTs are located on the low voltage side of the GSU transformer. The sample transformer diagram (first figure in this
chapter) shows this transformer to be Yd1. Consequently, due to the location of instrument transformers, Dy11 is chosen
for both the
XFMR VOL CONNECTION
Therefore "None" is chosen for both of the zone 3 transformer connection settings. Set the reach of the zone 1 element at
120% of impedance of the GSU transformer and the transmission line. In the instance that there are multiple lines and/or
multiple generators, the zone 1 reach must be increased to compensate for the infeed effect.
8
8-8
and settings. There are no transformers in the reverse direction.
XFMR CUR CONNECTION
CHAPTER 8: APPLICATION OF SETTINGS
menu.
G60 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
SETTINGS 
Eq. 8-25
Eq. 8-26
Eq. 8-27