GE 889 - Page 321

CHAPTER 4: SETPOINTS PROTECTION
889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL 4–191
Figure 4-67: Ground Directional Overcurrent Protection logic diagram
894157A1.cdr
FLEXLOGIC OPERAND
FLEXLOGIC OPERAND
SETTING SETTING SETTING SETTING
SETTINGS SETTING SETTING
GROUND FUNCTION :
DIR OC
GROUND VOLT :
DIR OC POL
GROUND POLARIZING :
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 Voltage Calculated V _0
}
}
Current Ground Crt (Ig) K1-CT Crt (Ipol) Dual
NOTE: CURRENT POLARIZING IS POSSIBLE ONLY IN RELAYS WITH THE GROUND CURRENT INPUTS CONNECTED TO AN ADEQUATE CURRENT POLARIZING SOURCE
Off=0 Enabled=1
AND
AND AND
AND
AND
AND
AND
OR OR
OR OR
Ipol 0.05xCT
Ig PICKUP
Ig PICKUP
Voltage Polarization
Current Polarization
-3V_0
3I_0
FWD
FWD FWD
REV REV
REV
RUN RUN RUN RUN
1.25 cy
1.5 cy
TO GROUND TOC AND
IOC ELEMENTS
TO GROUND TOC AND
IOC ELEMENTS
AND
SETPOINTS
SIGNAL INPUT :
CT Bank 1 - J1
USED ONLY IN 845 and 889
894157A1.cdr