Schweitzer Engineering Laboratories SEL-351A - Figure 9.7 I.E.C. Class B Curve (very Inverse): C2

9.12
SEL-351A Relay Instruction Manual Date Code 20080213
Setting the Relay
Time-Overcurrent Curves
Figure 9.7 I.E.C. Class B Curve (Very Inverse): C2
0.30
0.20
0.10
0.05
1.00
0.90
0.80
0.70
0.60
0.50
0.40
.01
.5 .6 .7 .8 .9 1
.02
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40
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30
70
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80
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100
80
10
2
3
6
4
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8
20
50
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90
Time in Seconds
Multiples of Pickup
Time in Cycles 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)
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