CHAPTER 6: SETPOINTS
S3 PROTECTION
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–87
Figure 25: Neutral directional logic diagram
Zero
Sequence
V
oltage
(-V0)
SETPOINT
NTRL
DIR
FUNCTION
Disabled
=
0
Latched
Alarm
SETPOINTS
BLOCK
1
Of
f
=
0
BLOCK
2
Of
f
=
0
BLOCK
3
Of
f
=
0
OR
NTRL
DIR
REVERSE
(T
o
Neutral
TO
C
and
Neutral
IOC
)
Alarm
OR
OR
REVERSE
(Message)
AND
SETPOINT
:
Operate
Output
Relays
Upon
Selection
OUTPUT
RELA
Y
4
OUTPUT
RELA
Y
5
OUTPUT
RELA
Y
6
OUTPUT
RELA
Y
3
Control
Neutral
Current
(In)
Ground
current
(Ig)
V
oltage
Polarization
-3V_0
3I_0
FWD
REV
REV
RUN
SETPOINT
NTRL
DIR
MT
A
Current
Polarization
REV
RUN
SETPOINT
NTRL
DIR
POLARIZING:
Current
Dual
V
oltage
OR
OR
SETPOINT
MIN
POL
VOL
T
AGE
|V0|
>
MINIMUM
AND
Ig>0
.0
5xC
T
AND
In>0
.0
5xC
T
AND
OR
XOR
AND
NAND
AND
Ntrl
Dir
Reverse
(Event
Recorder
,
T
ransient
Recorder)
Direction
OK
LED:
ALARM
RESET
Command
898017A1.cdr
AND
LA
TCH
S
R
