6–80
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION
CHAPTER 6: SETPOINTS
Figure 22: Neutral Timed Overcurrent Protection: Logic Diagram
SETPOINTS
Neutral
current
(IN)
RUN
SETPOINTS
BLOCK
1:
O
ff=0
NTRL
T
O
C
PICKUP:
NTRL
T
O
C
CUR
VE:
NTRL
T
O
C
TDM:
IN
>
PICKUP
BLOCK
2:
O
ff=0
BLOCK
3:
O
ff=0
OR
AND
Operate
Output
Relay
1
(TRIP)
Event
Recorder
T
ransient
Recorder
NTRL
T
O
C
PKP
LED:
TRIP
Event
Recorder
T
ransient
Recorder
OR
OR
NTRL
T
O
C
O
P
Adjust
PKP
Cold
Load
PKP
Computed
by
the
relay
Adjust
Neutral
T
OC
PKP
AND
SETPOINTS:
Operate
output
relays
upon
selection
OUTPUT
RELA
Y
4
OUTPUT
RELA
Y
5
OUTPUT
RELA
Y
6
OUTPUT
RELA
Y
3
AND
T
rip
(T
o
Breaker
Failure)
NTRL
T
O
C
RESET
:
SETPOINTS
NTRL
T
O
C
DIRECTION:
Forward
Disabled
Reverse
SETPOINT
NTRL
T
O
C
FUNCTION:
Disabled
=
0
Latched
Alarm
Alarm
T
rip
AND
AND
Current
in
Reverse
From
NEUTRAL
DIRECTIONAL
Current
OK
Autoreclose
(per
shot
settings)
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
LED:
PICKUP
Message:
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