GE Multilin 850, Instruction Manual

Page: 316 / 664

6–48 850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
CURRENT ELEMENTS CHAPTER 6: PROTECTION SETPOINTS
Figure 6-17: Sensitive Ground Directional Voltage-polarized Characteristics
Path :
Setpoints > Protection > Group 1(6) > Current > Sens Ground Directional OC 1(X)
FUNCTION
Range: Disabled, Enabled
Default: Disabled
POLARIZING MODE
Range: Voltage, Current, Dual
Default: Voltage
This setting selects the polarizing mode for the directional unit.
• If Voltage polarizing mode is selected, the element uses the zero-sequence voltage
angle for polarization. Select either the zero-sequence voltage V_0, calculated from
the phase voltages, or the zero-sequence voltage supplied externally as the auxiliary
voltage V_X.
The calculated V_0 can be used as polarizing voltage only if the voltage transformers
are connected in Wye. The auxiliary voltage can be used as the polarizing voltage if
the auxiliary voltage is connected to a zero-sequence voltage source (such as the
open delta connected secondary of VTs).
827805Y1.CDR
VAG
(reference)
VBG
VCG
-Isg line
Isg line
ECA line
-ECA line
LA
LA
LA
LA
ECA
FWD LA
line
FWD Operating
Region
REV Operating
Region
FWD LA
line
REV LA
line
REV LA
line
-3V_0 line
3V_0 line