GE Multilin 345 - Page 209

CHAPTER 6: SETPOINTS S4 CONTROLS
345 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 6–93
Figure 6-38: 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)
Alarm
OR
OR
Trip
Phase Currents
AND
Ia > PICKUP
OR
AND
SETPOINT
BF EXT INITIATE Off = 0
Range: Contact Input, Virtual Input, Remote Input, Logic Element
From Protection operation
OR
BF TIME DELAY 1
SETPOINT
t
PKP
RUN
BF TIME DELAY 2
SETPOINT
t
PKP
RUN
LED: ALARM
RESET
Command
AND
S R
LATCH
SETPOINTS
Do Not Operate, Operate
OUTPUT RELAY X
Message and Event Recorder
W1(W2) Breaker Failure
Ib > PICKUP Ic > PICKUP
897814A1.CDR