Schweitzer Engineering Laboratories SEL-587Z - Figure 3.19 U.S. very Inverse Curve: U3

3.21
Date Code 20020903 SEL-587Z Instruction Manual
Relay Elements
Overcurrent Protection
Figure 3.19 U.S. Very Inverse Curve: U3.
1
.00
0.50
1
0.00
5.00
3.00
2
.00
1
5.00
.01
.5
.6
.7
.8
.9
1
.0
2
.03
.04
.05
.09
.06
.08
.1
.2
.3
.4
.5
.7
.9
1
4
2
3
5
6
7
8
9
10
40
20
30
70
50
60
80
90
100
1
0
2
3
6
4
5
7
9
8
2
0
50
30
4
0
60
7
0
1
00
90
T
im
e
in
Seco
n
ds
T
ime in C
y
cles 60 Hz (50Hz)
3
(
2.5
)
6
(
5
)
15
(
12.5
)
30
(
25
)
60
(
50
)
600
(
500
)
150
(
125
)
300
(
250
)
1500
(
1250
)
3000
(
2500
)
6000
(
5000
)