GE 845 - Page 315

CHAPTER 4: SETPOINTS PROTECTION
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 4–187
Figure 4-64: Ground Directional Overcurrent Protection logic diagram
894158A1.cdr
POLARIZING VOLTAGE :
FLEXLOGIC OPERAND
FLEXLOGIC OPERAND
SETPOINT SETPOINT SETPOINT
SETPOINT SETPOINT SETPOINT
GROUND FUNCTION :
DIR OC
BLOCK :
GROUND LIMIT ANGLE :
DIR OC FWD
GROUND ECA:
DIR OC FWD
GROUND LIMIT ANGLE :
DIR OC REV
GROUND DIR OC FWD PICKUP : GROUND PICKUP :
DIR OC REV
Gnd Dir OC FWD
Gnd Dir OC REV
Disabled =0 Measured VX Calculated V _ 0
}
Ground Current (Ig)
Off=0 Enabled =1
AND
AND
AND
AND
AND
Ig PICKUP
Ig PICKUP
Voltage Polarization
-3V_0
Ig
FWD
FWD
REV
REV
RUN RUN RUN
1.25 cy
1.5 cy
TO GROUND TOC AND
IOC ELEMENTS
TO GROUND TOC AND
IOC ELEMENTS
AND
SETPOINT SIGNAL INPUT : CT Bank 1 – J1