Schweitzer Engineering Laboratories SEL-421-4 - Figure 5.81 U.S. Short-Time Inverse-U5

5.107
Date Code 20171021 Instruction Manual SEL-421 Relay
Protection Functions
Inverse-Time Overcurrent Elements
Figure 5.81 U.S. Short-Time Inverse—U5
0.50
1.00
2.00
6.00
3.00
4.00
5.00
10.00
8.00
12.00
15.00
.01
.5 .6 .7 .8 1.9
.02
.03
.04
.05
.06
.07
.1
.08
.09
.2
.3
.4
.5
.6
1
.7
.8
.9
2345678
10
9
20
30
50
40
60
100
90
70
80
80
9
2
3
4
5
6
7
8
10
20
30
40
50
60
70
90
100
Time in Seconds
Multiples of Pickup
Time in Cycles 60 Hz (50 Hz)
3 (2.5)
6 (5)
15 (12.5)
60 (50)
30 (25)
150 (125)
300 (250)
1500 (1250)
600 (500)
3000 (2500)
6000 (5000)