Page 5-10
FPU-32 Feeder Protection Unit
Rev.
2-A-103014
Protective Functions
CURRENT IN MULTIPLES OF PICKUP SETTING (I
M
)
TIME IN SECONDS (t)
IEEE VERY INVERSE
1
2
3
4
5
6
7
8
9 10
20
0.05
0.07
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
200
300
400
500
0.05
0.1
0.2
0.3
0.5
0.7
1.0
I
M
> 1.1: t = T
M
x 3 x (19.61/(I
M
2
- 1) + 0.491)
I
M
> 20: t = t
I
M
=20
I
M
< 0.9: t
reset
= T
M
x 3 x 21.6/(1 - I
M
2
)
Time
Multiplier
(T
M
)
FIGURE 5.8 IEEE Very Inverse Curves.
