6–72
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION
CHAPTER 6: SETPOINTS
Figure 6-30: Negative sequence instantaneous overcurrent protection logic diagram
Calculated Negative
Sequence Current
SETPOINTS
SETPOINT
NEG SEQ IOC FUNCTN
:
Disabled
=
0
Latched
Alarm
NEG SEQ IOC PICKUP
:
AND
Operate Output Relay 1
(TRIP)
Event Recorder
Transient Recorder
LED:
TRIP
Alarm
OR
OR
AND
SETPOINTS
Do Not Operate, Operate
OUTPUT
RELA
Y
X
Trip
AND
To
Breaker Failure
Trip
SETPOINTS
BLOCK
1:
Of
f=
0
BLOCK
2:
Of
f=
0
BLOCK
3:
Of
f=
0
OR
RUN
LED:
PICKUP
Event Recorder
Transient Recorder
NegSeq IOC
Message
I_2
>
PICKUP
NEG SEQ IOC DELA
Y
:
SETPOINT
t
PKP
I_2
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
0
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