The breaking category of DC load becomes far more severe in comparison with AC load. However, electromagnetic contactor can be applied as shown in Table 4.
Type of load | Time constant L/R (ms) | Voltage DC (V) | NO. of series contacts | Frame and rated operational current (A) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
8C, 10C, 11 | 20 | 25 | 35 | 50 | 65C | 80C | 100C 125C |
150C | 200C 250C |
300C 400C |
600C | ||||
Resistance load | Less than 1 | 24 | 1 | 15 | 25 | 30 | 50 | 60 | 70 | 90 | 120 | 170 | 200 | 300 | 600 |
48 | 1 | 15 | 25 | 30 | 50 | 60 | 70 | 90 | 120 | 170 | 200 | 300 | 600 | ||
2 | 15 | 25 | 30 | 50 | 60 | 70 | 90 | 120 | 170 | 200 | 300 | 600 | |||
110 | 2 | 15 | 25 | 30 | 50 | 60 | 70 | 90 | 120 | 170 | 200 | 300 | 600 | ||
3 | 15 | 25 | 30 | 50 | 60 | 70 | 90 | 120 | 170 | 200 | 300 | 600 | |||
220 | 3 | 15 | 25 | 30 | 50 | 60 | 70 | 90 | 120 | 170 | 200 | 300 | 600 | ||
DC motor | Less than 15 | 24 | 1 | 6 | 10 | 10 | 20 | 20 | 25 | 35 | 40 | 60 | 100 | 150 | 300 |
48 | 2 | 6 | 15 | 15 | 20 | 20 | 25 | 50 | 60 | 80 | 120 | 150 | 300 | ||
3 | 10 | 20 | 20 | 30 | 30 | 35 | 80 | 90 | 120 | 180 | 200 | 300 | |||
110 | 2 | 4 | 8 | 8 | 10 | 10 | 15 | 30 | 40 | 60 | 100 | 150 | 300 | ||
3 | 8 | 15 | 15 | 20 | 20 | 30 | 60 | 80 | 100 | 150 | 200 | 300 | |||
220 | 3 | 4 | 8 | 8 | 10 | 10 | 12 | 30 | 40 | 60 | 80 | 100 | 200 | ||
Coil load | Less than 40 | 24 | 1 | 3 | 5 | 5 | 7 | 7 | 10 | 20 | 20 | ||||
48 | 1 | 3 | 5 | 5 | 7 | 7 | 10 | 20 | 20 | ||||||
2 | 5 | 15 | 15 | 20 | 20 | 25 | 50 | 60 | |||||||
110 | 2 | 3 | 5 | 5 | 7 | 7 | 10 | 20 | 20 | ||||||
3 | 7 | 15 | 15 | 20 | 20 | 25 | 50 | 60 | |||||||
220 | 3 | 3 | 4 | 4 | 5 | 5 | 5 | 7 | 7 | ||||||
Less than 100 | 24 | 1 | 2 | 3 | 3 | 5 | 5 | 7 | 10 | 10 | |||||
48 | 1 | 2 | 3 | 3 | 5 | 5 | 7 | 10 | 10 | ||||||
2 | 5 | 7 | 10 | 15 | 15 | 15 | 30 | 35 | |||||||
110 | 2 | 2 | 3 | 3 | 5 | 5 | 7 | 10 | 10 | ||||||
3 | 5 | 7 | 10 | 15 | 15 | 15 | 30 | 35 | |||||||
220 | 3 | 2 | 3 | — | — | — | — | — | — |
Note