Thytronic NA011, Manual, Page: 77 / 95

APPENDIX
77 NA011 - Manual - 05 - 2022
‡ Residual overcurrent 50N/51N - 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
E
/ I
E
>>inv
I
E
/ I
E
>inv
0.01
0.1
1
10
100
1000
10000
100000
t [s]
10 s
60 s
t
E>
inv
t
E>>
inv
5 s
1 s
0.5 s 0.2 s 0.02 s 0.1 s
t = t
E
>
inv
·
[( I
E
/ I
E
>
inv
)
2
-1]
80
t = t
E
>>
inv
·
[( I
E
/ I
E
>>
inv
) 2 -1]
80
Note: match of operating and setting time takes place when I
E
/I
E
>
inv
or I
E
/I
E
>>
inv
= 9