GE 850 - Page 314

6–46 850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
CURRENT ELEMENTS CHAPTER 6: PROTECTION SETPOINTS
Figure 6-16: Sensitive Ground Instantaneous Overcurrent Protection logic diagram
894040A2.cdr
SETPOINTS
Sensitive Ground current (Isg)
RUN
SETPOINTS
BLOCK: Off = 0
PICKUP:
Isg > PICKUP
OR
AND
Operate Output Relay 1 (TRIP)
LED: TRIP
OR
OR
From Cold Load Pickup
From Sensitive Ground CT
AND AND
SETPOINT
FUNCTION: Disabled = 0
Trip Alarm
Latched Alarm
PICKUP DELAY:
SETPOINTS
t
PKP
From Autoreclose
(per shot settings)
LED: ALARM
RESET
Command
AND
S R
LATCH
LED: PICKUP
SETPOINTS
Do Not Operate, Operate OUTPUT RELAYS 3 to 7
DIRECTION:
DROPOUT DELAY:
t
RST
Configurable
SGnd IOC 1 PKP
FLEXLOGIC OPERANDS
SGnd IOC 1 OP
FLEXLOGIC OPERANDS
Direction (from Sens Ground
Directional OC element)
Set
Dominant
From Manual Close
Blocking