Sel 751A - Figure 4.12 U.S. Short-Time Inverse Curve: U5

4.21
Date Code 20100129 Instruction Manual SEL-751A Relay
Protection and Logic Functions
Basic Protection
Figure 4.12 U.S. Short-Time Inverse Curve: 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 (50Hz)
3 (2.5)
6 (5)
15 (12.5)
60 (50)
30 (25)
150 (125)
300 (250)
1500 (1250)
600 (500)
3000 (2500)
6000 (5000)