05
Figure 1 Thermal relay operation time – current characteristic curve
S
1
2
4
6
8
10
20
40
1
2
4
6
8
10
20
40
60
80
100
120
0.8
1 1
.
2
1
.
5
2
3
4
5
6 7 8 9 10
min
heat state
3 phase
2 phase
cold state
2 phase
3 phase
Amplification factor of setting current