Schweitzer Engineering Laboratories SEL-351A - Figure 9.6 I.E.C. Class a Curve (Standard Inverse): C1

9.11
Date Code 20080213 Instruction Manual SEL-351A Relay
Setting the Relay
Time-Overcurrent Curves
Figure 9.6 I.E.C. Class A Curve (Standard Inverse): C1
0.60
0.05
0.50
0.40
0.30
0.20
0.10
1.00
0.90
0.80
0.70
.01
.5 .6 .7 .8 .9 1
.02
.03
.04
.05
.09
.07
.06
.08
.1
.2
.3
.4
.5
.7
.6
.9
.8
1
423 56789
10
40
20
30
70
50
60
80
90
100
80
10
2
3
6
4
5
7
9
8
20
50
30
40
60
70
100
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)
Courtesy of NationalSwitchgear.com