Sel SEL-421 - OOS Override Logic; OOS Positive-Sequence Measurements

R.1.47
Date Code 20111215 Reference Manual SEL-421 Relay
Protection Functions
Out-of-Step Logic
Figure 1.31 OOS Positive-Sequence Measurements
Figure 1.32 OOS Override Logic
UBOSBD
D
0
(
Internal Function
)
U
B
OSB
3
φ
U
n
b
l
ock
X
1
X
1
X
1
R
1
R
1
R
1
Z
o
n
e
6
Z
o
n
e
7
1
1
Rela
y
W
o
r
d
Bi
ts
50
AB
C
50
AB
CP
3PO
ILOP
X7AB
C
X
6
AB
C
V
1
I
1L
|I1L|
+
—
Relay
Word
Bits
Setting
UBD
0
CYC
67QUBF
Relay
Word
Bits
UBD
0
CYC
67QUBR
Relay
Word
Bit
Relay
Word
Bit
32QF
Setting
3I2L
50QUBP
32QR
—
+