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NVA100X-D - Manual - 02 - 2016
APPENDIX
Residual overcurrent 50N.1/51N.1, 50N.2/51N.2 and 50N(Comp)/51N(Comp) - Extremely inverse time curve (EI)
—
F_51N-ANSIEI-Char.ai
1.1
2
3
4
5
6
7
8 9 10
20
I
E1
/
I
E1
>inv
I
E2
/
I
E2
>inv
I
EC
/
I
EC
>inv
0.01
0.1
1
10
100
1000
10000
t
[s]
10 s
60 s
5 s
0.5 s
1 s
0.2 s
0.1 s
0.02 s
t
=
t
E1
>
inv
·
[(
I
E1
/
I
E1
>
inv
)
2
-1]
5.64
+ 0.024
t
=
t
E2
>
inv
·
[(
I
E2
/
I
E2
>
inv
)
2
-1]
5.64
+ 0.024
Note: match of operating and setting time takes place when I
E1
/I
E1
>
inv
, I
E2
/I
E2
>
inv
or I
EC
/I
EC
>
inv
= 2.789
t
E1>inv
t
E2>inv
t
EC>inv
t
=
t
EC
>
inv
·
[(
I
EC
/
I
EC
>
inv
)
2
-1]
5.64
+ 0.024