GE 845 - Page 309

CHAPTER 4: SETPOINTS PROTECTION
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 4–181
Figure 4-61: Ground Time Overcurrent Protection logic diagram
894121A2.cdr
SETPOINTS
RUN
SETPOINTS
FUNCTION: Disabled = 0
Trip
PICKUP: CURVE: TDM:
Ig > PICKUP
AND
Operate Output Relay 1 (TRIP)
LED: PICKUP
LED: TRIP
Alarm
OR
OR
Adjust PKP
AND
Latched Alarm
AND
RESET:
Ground current (Ig)
From Ground CT
SETPOINTS
BLOCK: Off = 0
From Autoreclose
(per shot settings)
From Cold Load Pickup
LED: ALARM
RESET
Command
AND
S R
LATCH
SETPOINTS
Do Not Operate, Operate OUTPUT RELAYS
SETPOINTS INPUT: Phasor, RMS
Configurable
Ground TOC1 PKP
FLEXLOGIC OPERANDS
Ground TOC1 OP
FLEXLOGIC OPERANDS
DIRECTION:
Direction (from Ground
Directional OC element)
Set
Dominant
From Manual Close
Blocking
SETPOINTS
SIGNAL INPUT: CT Bank 1 – J1
CONFIGURABLE IN 845
USED ONLY IN 845/889
USED ONLY IN 845