CHAPTER 6: SETPOINTS
S4 CONTROLS
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–129
Figure 45: 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
T
ransient
Recorder
Alarm
OR
OR
T
rip
Phase
Currents
AND
SETPOINT
Operate
output
relays
upon
selection
OUTPUT
RELA
Y
4
OUTPUT
RELA
Y
5
OUTPUT
RELA
Y
6
OUTPUT
RELA
Y
3
Ib
>
PICKUP
Ia
>
PICKUP
Ic
>
PICKUP
OR
AND
SETPOINT
BF
EXT
INITIA
TE
O
ff=0
Range:
Contact
Input,
V
irtual
Input,
Remote
Input,
Logic
Element
From
Protection
operation
OR
BF
TIME
DELA
Y1
SETPOINT
t
PKP
RUN
BF
TIME
DELA
Y2
SETPOINT
t
PKP
RUN
Breaker
Failure
Message
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
898001.cdr