6–108
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION
CHAPTER 6: SETPOINTS
Figure 6-48: Positive sequence undervoltage logic diagram
Positive Sequence
V
oltage
(computed
)
SETPOINTS
SETPOINT
POS SEQ UV FUNCTION
:
Disabled
=
0
Latched
Alarm
POS SEQ UV PKP
:
POS SEQ UV CUR
VE
:
POS SEQ UV DELA
Y:
AND
Operate Output Relay
1
(TRIP
)
Event Recorder
Transient Recorder
LED
:ALARM
LED
:TRIP
Alarm
OR
OR
AND
AND
RESET
Command
SETPOINTS
Do Not Operate, Operate
OUTPUT
RELA
Y
X
Trip
AND
Trip (T
o Breaker Failure
)
OR
SETPOINTS
BLOCK
1
Of
f=
0
BLOCK
2:
Of
f=
0
BLOCK
3:
Of
f=
0
OR
RUN
V_
1
PICKUP
V_
1
>
Minimum
POS SEQ UV MIN V
:
SETPOINT
AND
LED
:PICKUP
Event Recorder
Transient Recorder
Pos Seq Undervoltage
Message
898853A1.cdr