Woodward highprotec MRI4, User Manual

Page: 422 / 727

Protective Elements
IEC Long Time Inverse
Various reset modes are available:
Resetting via characteristic, delayed and instantaneous.
Remark: For
I > 20⋅I
>
, the curve stops decreasing, the t-values are kept constant at the value for
I = 20⋅I
>
.
422 MRI4 DOK-HB-MRI4-2E
0.01 0.1
1 10 100
0.1
1
10
100
1000
0.05
0.1
0.2
0.5
1
1.5
t [s]
I / I> (multiples of pickup)
tchar =
P
d
o
c_
Z
0
3
Reset Trip
»Char« = IEC LINV
≤ 20
t
− 1
120
=
I
I>
If:
I
I>
1 <
tchar t
1−
120
=
I
I>
2
If: < 1
I
I>
tchar