CHAPTER 6: SETPOINTS
S3 PROTECTION
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–67
Figure 17: Phase instantaneous overcurrent protection logic diagram
SETPOINT
Phase
A
current
(IA)
RUN
SETPOINT
PH
IOC
FUNCTION:
Disabled
=
0
Latched
Alarm
PH
IOC
PICKUP:
PH
IOC
PKP
DELA
Y
:
AND
Phase
B
current
(IB)
Phase
C
current
(IC)
RUN
RUN
Operate
Output
Relay
1
(TRIP)
Event
Recorder
T
ransient
Recorder
LED:
PICKUP
LED:
TRIP
Event
Recorder
T
ransient
Recorder
Alarm
OR
OR
Cold
Load
PKP
Autoreclose
(per
shot
settings)
Phase
Currents
Block
Inputs
AND
SETPOINT
:
Operate
output
relays
upon
selection
OUTPUT
RELA
Y
4
OUTPUT
RELA
Y
5
OUTPUT
RELA
Y
6
OUTPUT
RELA
Y
3
Tr
ip
AND
SETPOINT
BLOCK
1:
O
ff=0
BLOCK
2:
O
ff=0
BLOCK
3:
O
ff=0
OR
Message
Phase
IOC
OP
IB
>
PICKUP
IA
>
PICKUP
IC
>
PICKUP
SETPOINT
Phase
IOC
AO
P
Phase
IOC
BO
P
Phase
IOC
CO
P
Phase
IOC
A
PKP
Phase
IOC
B
PKP
Phase
IOC
C
PKP
Phase
IOC
PKP
Message
t
PKP
0
t
PKP
0
t
PKP
0
OR
OR
Tr
ip
(T
o
Breaker
Failure)
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
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