GE Multilin 350 Series Instruction Manual page 192

S3 PROTECTION
6–76
Courtesy of NationalSwitchgear.com
MIN POL VOLTAGE
Range: 0.05 to 1.25 x VT in steps of 0.01
Default: 0.05 x VT
The minimum zero sequence voltage level must be selected to prevent operation due to
normal system unbalances, or voltage transformer errors. Set the minimum zero
sequence voltage level to 2% of VT for well balanced systems, and 1% of VT accuracy.
For systems with high resistance grounding or floating neutrals, this setting can be as
high as 20%. The default of 5% of VT is appropriate for most solidly grounded systems.
The following table shows the operating current, and the polarizing signals used for
directional control:
Table 9: Ground Directional characteristics
Quantity Operating Current
Ground Ig
OUTPUT RELAY 3 to 6
Range: Do not operate, Operate
Default: Do not operate
Any or all of the output relays 3 to 6 can be selected to operate upon Gnd (S. Gnd)
Directional operation. The selection of relay outputs operation is available no matter
whether Latched Alarm, Alarm, or Trip function is selected.
BLOCK 1/2/3
Range: Off, Contact Input 1 to 10[8], Virtual Input 1 to 32, Remote Input 1 to 32, Logic
Element 1 to 16
Default: Off
Three blocking inputs are provided in the Ground Directional menu. One blocking input
going "high" is enough to block the function. The selection for each block can be Contact
input, Virtual Input, Remote Input, or Logic Element.
Polarizing Voltage
-Vo
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: SETPOINTS