Thytronic SME2-IS - First Protection Threshold 50;51 - IEC Extremely Inverse Time Curves (Type C, VIT)

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SME2-IS - Manual - 06 - 2021
APPENDIX
 First protection threshold 50/51 - IEC extremely inverse time curves (type C, VIT)
F_51-IECC-Char.ai
1.1
2 3 4 5 6 7 8 9 10 20
I /I >inv
0.01
0.1
1
10
100
1000
10000
100000
t [s]
10 s
60 s
5 s
1 s
0.5 s0.2 s0.02 s 0.1 s
t =
t>
inv
·
[(I/I>
inv
)
2
-1]
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Note: the set actuation time refers to a ratio /I>
inv
= 9
t>
inv