Thytronic Pro-N NVA100X-D

APPENDIX
337
NVA100X-D - Manual - 02 - 2016
Ground directional overcurrent - 67N - Extremely inverse time curve (IEC 60255-3/BS142 type C)—
F_67N-IECC-Char.ai
1.1
2 3 4 5 6 7 8 9 10 20
I
ED
/I
ED
>inv
I
ED
/I
ED
>>inv
0.01
0.1
1
10
100
1000
10000
100000
t [s]
t
ED
>
inv
= 10 s
t
ED
>
inv
= 10 s
t
ED
>
inv
= 60 s
t
ED
>>
inv
= 60 s
t
ED
>
inv
= 5 s
t
ED
>
inv
= 5 s
t
ED
>
inv
= 1 s
t
ED
>
inv
= 1 s
t
ED
>
inv
= 0.5 s
t
ED
>>
inv
= 0.5 s
t
ED
>
inv
= 0.2 s
t
ED
>>
inv
= 0.2 s
t
ED
>
inv
= 0.02 s
t
ED
>>
inv
= 0.02 s
t
ED
>
inv
= 0.1 s
t
ED
>>
inv
= 0.1 s
Note: match of operating and setting time takes place when I
ED
/I
ED
>
inv
= 9 o I
ED
/I
ED
>>
inv
= 9
t =
t
ED
>>
inv
·
[(I
ED
/I
ED
>>
inv
)
2
-1]
80
t =
t
ED
>
inv
·
[(I
ED
/I
ED
>
inv
)
2
-1]
80