Thytronic Pro-N NVA100X-D - Ground Directional Overcurrent 67 N(Comp) - Standard Inverse Time Curve (IEC 60255-3;BS142 Type A)

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NVA100X-D - Manual - 02 - 2016
APPENDIX
Ground directional overcurrent 67N(Comp) - Standard inverse time curve (IEC 60255-3/BS142 type A)—
F_51-IECA-Char.ai
1.1
2 3 4 5 6 7 8 9 10 20
I
ECH
/I
EDC
>
inv
I
ECL
/I
EDC
>
inv
0.01
0.1
1
10
100
1000
10000
t [s]
10 s
60 s
5 s
1 s
0.5 s
0.2 s
0.1 s
0.02 s
t
EDC
>
inv
Note: match of operating and setting time takes place when I
ECL
/I
EDC
>
inv
o I
ECH
/I
EDC
>
inv
= 700
t =
t
EDC
>
inv
·
[(I
ECL
/I
EDC
>
inv
)
0.02
-1]
0.14
t =
t
EDC
>
inv
·
[(I
ECH
/I
EDC
>
inv
)
0.02
-1]
0.14