Sel SEL-421 - OOS Logic Relay Settings

R.1.45
Date Code 20111215 Reference Manual SEL-421 Relay
Protection Functions
Out-of-Step Logic
➤ Setting R1R6 must be set less than R1R7.
➤ Setting R1L6 must be set greater than R1L7.
➤ Setting X1T6 must be set less than X1T7.
➤ Setting X1B6 must be set greater than X1B7.
➤ The minimum separation between settings R1R6 and R1R7 is
0.25/I
nom
.
➤ The minimum separation between settings R1L6 and R1L7 is
0.25/I
nom
.
➤ The minimum separation between settings X1T6 and X1T7 is
0.25/I
nom
.
➤ The minimum separation between settings X1B6 and X1B7 is
0.25/I
nom
.
➤ Setting OSBD must be greater than OSTD by a minimum of
0.5 cycle.
Table 1.40 OOS Logic Relay Settings
Name Description Range
Default
(5 A)
EOOS Out-of-Step Y, N N
OOSB1 Block Zone 1 Y, N Y
OOSB2 Block Zone 2 Y, N Y
OOSB3 Block Zone 3 Y, N Y
OOSB4 Block Zone 4 Y, N N
OOSB5 Block Zone 5 Y, N N
OSBD Out-of-Step Block Time Delay (cycles) 0.500–8000 2.000
OSBLTCH Latch Out-of-Step Blocking
a
a
The OSB (Out-of-Step Blocking) logic resets automatically after it asserts for more than
2 seconds. You can latch OSB if the power swing moves outside of Zone 6 before the two-second
timer expires.
Y, N N
EOOST Out-of-Step Trip Delay
b
b
Option I enables tripping on the way into Zone 6; option O enables tripping on the way out of
Zone 6; option N disabled OST (Out-of-Step Trip).
N, I, O N
OSTD Out-of-Step Trip Delay (cycles) 0.500–8000 0.500
X1T7 Zone 7 Reactance
—Top () (0.25–480)/I
nom
23.00
X1T6 Zone 6 Reactance
—Top () (0.25–480)/I
nom
21.00
R1R7 Zone 7 Resistance
—Right () (0.25–350)/I
nom
23.00
R1R6 Zone 6 Resistance
—Right () (0.25–350)/I
nom
21.00
X1B7
c
c
Advanced Setting if EADVS := Y. If the Advanced Settings are not enabled (setting EADVS := N),
the relay hides the setting.
Zone 7 Reactance—Bottom () (–0.25–480)/I
nom
–23.00
X1B6
c
Zone 6 Reactance—Bottom () (–0.25–480)/I
nom
–21.00
R1L7
c
Zone 7 Resistance—Left () (–0.25–350)/I
nom
–23.00
R1L6
c
Zone 6 Resistance—Left () (–0.25–350)/I
nom
–21.00
50ABCP
c
Pos.-Seq. Current Supervision (A) (0.20–20) • I
nom
1.00
50QUBP
c
Neg.-Seq. Current Supervision (A) (OFF, 0.10–20) • I
nom
OFF
UBD
c
Neg.-Seq. Current Unblock Delay (cycles) 0.500–120 0.500
UBOSBF
c
Out-of-Step Angle Unblock Rate 1–10 4