6–136
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
S4 CONTROLS
CHAPTER 6: SETPOINTS
Figure 6-59: Breaker failure logic diagram
SETPOINT
Phase
A current (Ia)
SETPOINT
BF FUNCTION:
Disabled = 0
Latched
Alarm
BF CURRENT
:
Phase B current (Ib)
Phase C current (Ic)
Event Recorder
Transient Recorder
Alarm
OR
OR
T
rip
Phase Currents
AND
SETPOINT
Do Not Operate, Operate
OUTPUT
RELA
Y X
Ib
>
PICKUP
Ia
>
PICKUP
Ic
>
PICKUP
OR
AND
SETPOINT
BF EXT
INITIA
TE
Off = 0
Range: Contact Input,
V
irtual Input, Remote Input,
Logic Element
From Protection operation
OR
BF
TIME DELA
Y 1
SETPOINT
t
PKP
RUN
BF
TIME DELA
Y 2
SETPOINT
t
PKP
RUN
Breaker Failure
Message
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
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