Normally Inverse Time-Delay Trip Curve (Ni) For Overcurrent Protection - ABB PR521 Operator's Manual

10.2. Curva di intervento a tempo normalmente
inverso (NI) per protezione da sovracorrente
t [s]
100
10
1
0.1
0.01
32/40 - 647008/002 - 2000/05 it-en
1.3 2 3 4 5
t= K x
10.2. Normally inverse time-delay trip curve (NI)
for overcurrent protection
IEC 255-3
Normal Inverse Curve
6 8 10 20
7 9
0.14
0.02
[ ] I
-1
I>
I>
30 40 60
I/I>
50