Thytronic Pro-N NVA100X-D - Phase overcurrent 50;51 side H and side L - Extremely inverse time curve (IEC 60255-3;BS142 type C)

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NVA100X-D - Manual - 02 - 2016
APPENDIX
Phase overcurrent 50/51 side H and side L - Extremely inverse time curve (IEC 60255-3/BS142 type C)—
F_51-IECC-Char.ai
1.1
2 3 4 5 6 7 8 9 10 20
I /I
(H)
>inv
I /I
(L)
>inv
0.01
0.1
1
10
100
1000
10000
100000
t [s]
10 s
60 s
5 s
1 s
0.5 s0.2 s0.02 s 0.1 s
t =
t
(H)
>
inv
t
(H)
>
inv
t
(L)
>
inv
·
[(I/I
(H)
>
inv
)
2
-1]
80
t =
t
(L)
>
inv
·
[(I/I
(L)
>
inv
)
2
-1]
80
Nota: il tempo d’intervento impostato è riferito ad un valore di corrente pari a I/I
(H)
>
inv
o I/I
(L)
>
inv
= 9