GE Multilin 850, Instruction Manual

Page: 319 / 664

CHAPTER 6: PROTECTION SETPOINTS CURRENT ELEMENTS
850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL 6–51
Figure 6-18: Sensitive Ground Directional Overcurrent Protection logic diagram
FLEXLOGIC OPERAND
FLEXLOGIC OPERAND
SETTING SETTING SETTING SETTING
SETTINGS SETTING SETTING
SENS GND FUNCTION:
DIR OC
SENS GND VOL
T
:
DIR OC POL
SENS GND POLARIZING:
DIR OC
BLOCK:
SENS GND LIMIT
ANGLE:
DIR OC FWD
SENS GND ECA:
DIR OC FWD
SENS GND LIMIT
ANGLE:
DIR OC REV
SENS GND PICKUP:
DIR OC FWD
SENS GND PICKUP:
DIR OC REV
S Gnd Dir OC FWD
S Gnd Dir OC REV
Disabled=0 Measured VX V
oltage
Calculated V_0
}
}
Current Ground Crt (Ig) Sens Gnd Crt (Isg) Dual
NOTE: CURRENT
POLARIZING IS POSSIBLE ONL
Y
IN RELA
YS WITH
THE GROUND CURRENT
INPUTS CONNECTED
T
O
AN
ADEQUA
TE CURRENT
POLARIZING SOURCE
Of
f=0
Enabled=1
AND
AND AND
AND
AND
AND
AND
OR OR
OR OR
Ig 0.05xCT
Isg PICKUP
Isg PICKUP
V
oltage Polarization
Current Polarization
-3V_0
3I_0
FWD
FWD FWD
REV REV
REV
RUN RUN RUN RUN
1.25 cy
1.5 cy
892782A2.cdr
T
O
SENS GND T
O
C
AND
IOC ELEMENTS
T
O
SENS GND T
O
C
AND
IOC ELEMENTS
AND
SETPOINTS
P
O
L
ARIZING V
O
L
SUP
V
:
lV
_
0I I
ʅ
0
.005
x V
T
IVxI
ʅ
0.
005
x V
T
USED ONL
Y
IN 850