GE Multilin g60 Instruction Manual page 512

10.1 SETTING EXAMPLE
The time delay should be longer than the longest normal clearing time for faults outside the generator zone. If the phase
VTs are wye-connected then this element should also be coordinated with VT secondary fuses to prevent false operations
for VT secondary ground faults. For the sample system a time delay of 1 second will be used. Make the following changes
in EnerVista UR Setup or through the
menu:
AUXILIARY OV1
b) 100% STATOR GROUND
The auxiliary voltage input is required for both the 100% stator ground and the third harmonic neutral undervoltage ele-
ments. Therefore the NEUTRL source will be assigned for these elements. Make the following changes in the

GROUPED ELEMENTS
STATOR GROUND SOURCE:
This 100% stator ground element provides ground fault protection for the neutral end of the stator winding. The element
has two stages. In this application, stage 1 is used to trip the machine and stage 2 is used for alarm purposes. Set the
pickup to 0.15 for both stages to provide adequate overlap with the auxiliary overvoltage element. Set stage 1 to 0.375 V
secondary (this value may be increased for security in particularly noisy environments). Stage 2 is typically set at 0.3 V sec-
ondary. The supervision settings are expressed in per unit of the
settings are 5 seconds and 1 second for the Stage 1 and Stage 2 elements respectively.
STG1 SUPV
Make the following changes in EnerVista UR Setup or through the

1 STATOR GROUND
10
10-8

SETTINGS
 
SETTING GROUP 1 STATOR GROUND
"SRC 2" (the "NEUTRL" source)
0.375 V
-------------------- - 0.0057 pu
= =
66 V
 menu:
100% STATOR GROUND
G60 Generator Protection System

GROUPED ELEMENTS SETTING GROUP 1
menu
NOMINAL PHASE VT SECONDARY
0.300 V
STG2 SUPV -------------------- -
,
=
66 V

SETTINGS GROUPED ELEMENTS
10 APPLICATION OF SETTINGS

VOLTAGE ELEMENTS
setting. The time delay
0.0045 pu
=

SETTING GROUP
GE Multilin

SETTINGS
(EQ 10.30)