Sel SEL-421 - LOP Logic

R.1.26
SEL-421 Relay Reference Manual Date Code 20111215
Protection Functions
Loss-of-Potential Logic
Figure 1.17 LOP Logic
—
Δ
| V
1
| > 10%
| V
0
| / | V
1
| > 10%
3PO
SPO
R
eset has
priority
LOP
ELOP := Y, Y1
ILOP
| V
1
| (last cycle) > 8% V
nom
| V
1
| > 85% V
n
om
| I
G
| > 5% I
n
om
| I
1
| > 5% I
nom
| I
1
| > 2% I
nom
| V
0
| > 15% | V
1
|
| I
G
| > 15% | I
1
|
| V
1
| > 15% V
nom
Δ| I
G
| > 6% I
n
om
Δ| I
1
| > 2% I
nom
| I
G
| (last
cycle) > 5% I
n
om
| I
1
|
(last cycle)
> 5
% I
nom
LOP (last interval)
15
CYC
0
0
CYC
30
3PO
SPO
OOSDET
0
70
C
YC
0
2
C
YC
60
CYC
0
Δ∠
I
1
> 5˚
Δ∠
I
G
> 5˚
3PO
−Δ
| V
1
| > 10%
S
R
Q
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Bits
Setting
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