Schweitzer Engineering SEL-387-0 - Figure 3.32 U.S. Short-Time Inverse Curve: U5

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Date Code 20170601 Instruction Manual SEL-387-0, -5, -6 Relay
Differential, Restricted Earth Fault, Thermal, and Overcurrent Elements
Time-Overcurrent Curves
Figure 3.32 U.S. Short-Time Inverse Curve: U5
.01
.5 .6 .7 .8 1.9
.02
.03
.04
.05
.06
.07
.1
.08
.09
.2
.3
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.5
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1
.7
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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)
0.50
1.00
2.00
6.00
3.00
4.00
5.00
10.00
8.00
12.00
15.00