Technical data
11/98
©1995 Square D—All Rights Reserved
40
Trip Curves
Ground-fault Protection STR 38S–STR 58U Control Units
06313081
.15
Multiple of Current Sensor (In)
Time in Seconds
I t OFF
Ground-fault Pickup
Ih = 0.1 x In 1200 A Max.
I t ON
1 1.2 1.5 2 3 4.5 .6 .7 .8 .9 5 106 7 8 9 20 30 40 50 60
70
80
90
100
200
300
400
500
600
700
800
900
1000
.4.3.2
.05
.06
.07
.08
.09
.1
.01
.001
.002
.003
.004
.005
.006
.007
.008
.009
.1
.02
.03
.04
.05
.06
.07
.08
.09
1
.2
.3
.4
.5
.6
.7
.8
.9
10
2
3
4
5
6
7
8
9
30
40
20
50
60
70
80
90
100
200
300
400
500
600
700
800
900
1000
.01
.001
.002
.003
.004
.005
.006
.007
.008
.009
.1
.02
.03
.04
.05
.06
.07
.08
.09
1
.2
.3
.4
.5
.6
.7
.8
.9
10
2
3
4
5
6
7
8
9
30
40
20
50
60
70
80
90
100
200
300
400
500
600
700
800
900
1000
.12
.15
1 1.2 1.5 2 3 4.5 .6 .7 .8 .9 5 106789 20
30 40 50 60
70
80
90
100
200
300
400
500
600
700
800
900
1000
.4.3.2
.05
.06
.07
.08
.09
.1
.12
0.1
0.2
0.3
0.4
2
2