GE Multilin 345 - Page 194

6–78 345 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION CHAPTER 6: SETPOINTS
Figure 6-32: 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
Message and Event Recorder
Message and 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 =
NEG SEQ TOC OP
SETPOINTS
(configurable only if “TRIP”
function selected)
Operate trip output relays upon selection
RLY2 TRIP W2 BKR RLY1 TRIP W1 BKR
NEG SEQ TOC PKP
897807A1.cdr