6–102
345 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION
CHAPTER 6: SETPOINTS
Figure 30: Neutral Timed Overcurrent Protection logic diagram
SE
TP
OINTS
RUN
SE
TP
OINT
NTRL
TO
C
FUNCTION
Disabled
=
0
Alarm
NTRL
TO
C
PICK
UP
NTRL
TO
C
CURVE
NTRL
TO
C
TDM
IN
>
PICK
UP
AND
LED:
PICK
UP
Latched
Alarm
OR
Trip
NTRL
TO
C
RESE
T
SE
TP
OINTS
BL
OCK
1
O
ff=0
BL
OCK
2
O
ff=0
BL
OCK
3
O
ff=0
OR
NTRL
TO
C
CT
INPUT
Message
and
Ev
ent
Recor
der
NTRL
TO
C
PKP
LED:
TRIP
OR
AND
SETPOINTS
:
Operate
output
relays
upon
selection
OUTPUT
REL
AY
4
OUTPUT
REL
AY
5
OUTPUT
REL
AY
6
OUTPUT
REL
AY
3
AND
To
Br
eaker
Failur
e
Trip
Message
and
Ev
ent
Recor
der
LED:
AL
ARM
RESE
T
Command
AND
S
R
LA
TC
H
NTRL
TO
C
O
P
SE
TP
OINTS
(configurable
on
ly
if
“TRIP
”
function
select
ed)
Operate
trip
output
relays
upon
selection
RL
Y
1
TRIP
W1
BKR
Neutral
curr
ent
(IN)
CT(W2),
CT(W
2)
neutral
current
computed
by
the
relay
RL
Y
2
TRIP
W2
BKR
897812.cdr