GE 350-A9

CHAPTER 6: SETPOINTS S3 PROTECTION
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL 6–63
Figure 6-26: Negative Sequence Timed Overcurrent logic diagram
Calculated Negative
Sequence Current
SETPOINT
NEG SEQ TOC FUNCTN: Disabled = 0
Latched Alarm
AND
LED: TRIP
Alarm
OR
OR
AND
SETPOINTS
Do Not Operate, Operate
OUTPUT RELAY X
Trip
AND
To Breaker Failure
Trip
SETPOINTS
BLOCK 1: Off = 0 BLOCK 2: Off = 0 BLOCK 3: Off = 0
OR
LED:
PICKUP
Event Recorder
Event Recorder
I_2
LED: ALARM
RESET
Command
AND
S R
LATCH
SETPOINTS
RUN NEG SEQ TOC PICKUP NEG SEQ TOC CURVE NEG SEQ TOC TDM
I_2 > PICKUP
Adjust PKP
NEG SEQ TOC RESET
I_2 x t =
Transient Recorder
897807A1.cdr
Operate Output Relay 1
Transient Recorder