Page 5-4
FPU-32 Feeder Protection Unit
Rev.
2-A-103014
Protective Functions
CURRENT IN MULTIPLES OF PICKUP SETTING (I
M
)
TIME IN SECONDS (t)
IEC NORMAL INVERSE
1
2
3
4
5
6
7
8
9 10
20
0.1
0.2
0.3
0.4
0.5
0.7
1
2
3
4
5
7
10
20
30
40
50
70
100
1
0.05
0.1
0.2
0.3
0.5
0.7
I
M
> 1.1: t = T
M
x 0.14/(I
M
0.02
- 1)
I
M
> 20: t = t
I
M
=20
I
M
< 0.9: t
reset
= T
M
x 0.14/(1 - I
M
0.02
)
Time
Multiplier
(T
M
)
FIGURE 5.2 IEC Normal Inverse, Curve Type A.