CHAPTER 6: SETPOINTS
S3 PROTECTION
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–109
Figure 37: Overfrequency logic diagram
Phase
V
oltage
Inputs
(associated
setpoints)
SETPOINT
Va
b
SETPOINT
OVERFREQ
FUNCTN:
Disabled
=
0
Latched
Alarm
OVERFREQ
PKP:
Vbc
Vca
Operate
Output
Relay
1
(TRIP)
Event
Recorder
T
ransient
Recorder
LED:
TRIP
Alarm
OR
OR
AND
SETPOINTS
Operate
output
relays
upon
selection
OUTPUT
RELA
Y
4
OUTPUT
RELA
Y
5
OUTPUT
RELA
Y
6
OUTPUT
RELA
Y
3
T
rip
AND
T
rip
(T
o
B
reaker
Failure)
SETPOINTS
BLOCK
1:
Of
f
=
0
BLOCK
2:
Of
f
=
0
BLOCK
3:
Of
f
=
0
OR
RUN
Va
n
Vbn
Vcn
AND
Delta
Wy
e
LED:
PICKUP
Event
Recorder
T
ransient
Recorder
Overfrequency1(2)
Message
f
>
PICKUP
Frequency
Measurement
f
(
V
a)
-
frequency
OVERFREQ
DELA
Y:
SETPOINT
t
PKP
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
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V
a<0
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T
