Schweitzer Engineering Laboratories SEL-351 - Page 348

9-6 Setting the Relay Date Code 20001006
SEL-351 Instruction Manual
Figure 9.8: I.E.C. Class C Curve (Extremely
Inverse): C3
Figure 9.9: I.E.C. Long-Time Inverse
Curve: C4
10
20
30
40
50
60
70
80
90
100
1
2
3
4
5
6
7
8
9
.1
.2
.3
.4
.5
.6
.7
.8
.9
.01
.02
.03
.04
.05
.06
.07
.08
.09
100
1 2 3 4 5 6 7 8 9.5 .6 .7 .8 .9
90 80 70 60 50 40 30 20 10
Time in Seconds
Time in Cycles 60 Hz (50Hz)
6000 (5000)
3000 (2500)
1500 (1250)
600 (500)
300 (250)
150 (125)
60 (50)
30 (25)
15 (12.5)
6 (5)
3 (2.5)
DWG. M300G153
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
Figure 9.10: I.E.C. Short-Time Inverse
Curve: C5
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