Thytronic Pro-N NVA100X-D

354
NVA100X-D - Manual - 02 - 2016
APPENDIX
Directional ground overcurrent 67N(Comp) - Moderately inverse time curve (ANSI/IEEE type MI)—
F_67NC-ANSIMI-Char.ai
1.1
2 3 4 5 6 7 8 9 10 20
0.01
0.1
1
10
100
1000
10000
t [s]
10 s
60 s
5 s
1 s
0.02 s 0.2 s 0.5 s
0.1 s
Note: match of operating and setting time takes place when I
EDH
/I
EDC
>
inv
or I
EDL
/I
EDC
>
inv
= 1.664
I
EDH
/I
EDC
>inv
I
EDL
/I
EDC
>inv
t =
t
EDC
>
inv
·
[(I
EDH
/I
EDC
>
inv
)
0.02
-1]
0.01
+ 0.023
t =
t
EDC
>
inv
t
EDC
>
inv
·
[(I
EDL
/I
EDC
>
inv
)
0.02
-1]
0.01
+ 0.023