Thytronic Pro-N NVA100X-D - Ground Directional Overcurrent 67 N - Electromechanical Inverse Curves (EM)

APPENDIX
365
NVA100X-D - Manual - 02 - 2016
Ground directional overcurrent 67N - Electromechanical inverse curves (EM)—
F_67N-EM-Char.ai
1.1
2 345678910 20
0.01
0.1
1
10
100
1000
10000
t [s]
I
ED
/I
ED
>inv
I
ED
/I
ED
>>inv
0.1 s
0.02 s
10 s
5 s
1 s
0.5 s
0.2 s
60 s
t
ED
>
inv
t
ED
>>
inv
Note: match of operating and setting time takes place when I
ED
/I
ED
>
inv
= 4 or I
ED
/I
ED
>>
inv
= 4
t =
t
ED
>
inv
·
[-0.236 · (I
ED
/I
ED
>
inv
)
-1
+ 0.339]
0.28
t =
t
ED
>>
inv
·
[-0.236 · (I
ED
/I
ED
>>
inv
)
-1
+ 0.339]
0.28