3.75
Date Code 20170601
Instruction Manual
SEL-387-0, -5, -6 Relay
Differential, Restricted Earth Fault, Thermal, and Overcurrent Elements
Time-Overcurrent Curves
Figure 3.36
IEC 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
.1
.9
.8
1
.4
.2
.3
.5
.6
.8
.7
.9
1
2
3
4
5
7
6
4
2
3
7
6
5
10
9
8
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)
Summary of Contents for SEL-387-0
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