Sel SEL-421 - Flashover Protection Logic Diagram; Circuit Breaker Failure Trip Logic Diagram

R.1.125
Date Code 20111215 Reference Manual SEL-421 Relay
Protection Functions
Circuit Breaker Failure Protection
Figure 1.80 Flashover Protection Logic Diagram
Figure 1.81 Circuit Breaker Failure Trip Logic Diagram
EFOBFn := Y
50FOAn
52AAn
BLKFOAn
Relay Word bit BLKFOAn asserts if an A-phase
single-pole trip occurs, or if the corresponding
circuit breaker closes.
n = 1 or 2; corresponds to
Circuit Breaker 1 or
Circuit Breaker 2
BnOPHA
50FOn
IABKn
FOBFn
FOAn
FOBn
FOCn
Relay
Word
Bit
Relay
Word
Bit
Relay
Word
Bits
Relay
Word
Bits
5 CYC
0
FOPUn
0
6 CYC
0
SELOGIC
Settings
S
R
Q
—
+
Setting
BFTRIPn
Relay
Word
Bit
TDURTn
Relay
Word
Bit
TRGTR
Relay
Word
Bit
SELOGIC
Settings
TDUR3D
0
TAR R
Serial Port
Command
Target Reset
Front Panel
BFULTRn
BFTRn
RSTTRGT