Schweitzer Engineering Laboratories SEL-421-4 - Figure 5.86 IEC Short-Time Inverse-C5

5.112
SEL-421 Relay Instruction Manual Date Code 20171021
Protection Functions
Inverse-Time Overcurrent Elements
Figure 5.86 IEC Short-Time Inverse—C5
10
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60
70
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90
100
1
2
3
4
5
6
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9
.1
.2
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.5
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.01
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100
123456789.5 .6 .7 .8 .9
90
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10
Time in Seconds
Time in Cycles 60 Hz (50 Hz)
6000 (5000)
3000 (2500)
1500 (1250)
600 (500)
300 (250)
150 (125)
60 (50)
30 (25)
15 (12.5)
6 (5)
3 (2.5)
Multiples of Pickup
0.05
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00