Schweitzer Engineering Laboratories SEL-351A - Figure 9.9 I.E.C. Long-Time Inverse Curve: C4

9.14
SEL-351A Relay Instruction Manual Date Code 20080213
Setting the Relay
Time-Overcurrent Curves
Figure 9.9 I.E.C. Long-Time Inverse Curve: C4
0.20
0.10
0.05
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
.7.6.5
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.9.8 1
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423 765
10
98
40
20
30
70
50
60
80
90
100
50
9
8
10
20
30
40
300
200
100
80
60
70
90
1000
900
800
700
600
500
400
Time in Seconds
Multiples of Pickup
Time in Cycles 60 Hz (50Hz)
30 (25)
60 (50)
150 (125)
300 (250)
3000 (2500)
600 (500)
1500 (1250)
6000 (5000)
15000 (12500)
30000 (25000)
60000 (50000)
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