| Controls
Amperage Selector |
Heater
KW |
Heating Load Amperage |
| Single Phase |
Three Phase |
| 120V |
208V |
240V |
480V |
208V |
240V |
480V |
600V |
| 0.5 |
4.2 |
2.4 |
2.1 |
1.1 |
1.4 |
1.2 |
0.6 |
0.5 |
| 1.0 |
8.4 |
4.8 |
4.2 |
2.1 |
2.8 |
2.5 |
1.2 |
1.0 |
| 2.0 |
16.7 |
9.7 |
8.4 |
4.2 |
5.6 |
4.9 |
2.5 |
1.9 |
| 3.0 |
25.0 |
14.5 |
12.5 |
6.3 |
8.4 |
7.3 |
3.7 |
2.9 |
| 4.0 |
33.4 |
19.3 |
16.7 |
8.4 |
11.2 |
9.7 |
4.9 |
3.9 |
| 5.0 |
41.7 |
24.0 |
20.8 |
10.4 |
14.0 |
12.1 |
6.0 |
4.8 |
| 6.0 |
50.0 |
28.9 |
25.0 |
12.5 |
16.7 |
14.5 |
7.3 |
5.8 |
| 7.0 |
58.3 |
33.7 |
29.2 |
14.6 |
19.5 |
16.9 |
8.4 |
6.7 |
| 8.0 |
66.7 |
38.5 |
33.4 |
16.7 |
22.3 |
19.3 |
9.7 |
7.7 |
| 9.0 |
75.0 |
43.3 |
37.5 |
18.8 |
25.1 |
21.7 |
10.9 |
8.7 |
| 10.0 |
83.3 |
48.1 |
41.7 |
20.9 |
27.8 |
24.1 |
12.0 |
9.6 |
| 12.0 |
100.0 |
57.7 |
50.0 |
25.0 |
33.4 |
29.0 |
14.5 |
11.6 |
| 15.0 |
125.0 |
72.1 |
62.5 |
31.2 |
41.7 |
36.1 |
18.1 |
14.5 |
| 18.0 |
150.0 |
88.6 |
75.0 |
37.5 |
50.1 |
43.4 |
21.7 |
17.3 |
| 21.0 |
175.0 |
101.0 |
87.5 |
43.8 |
58.3 |
50.6 |
25.3 |
20.5 |
| 24.0 |
200.0 |
115.4 |
100.0 |
50.0 |
66.7 |
57.8 |
28.9 |
23.0 |
| 27.0 |
225.0 |
129.9 |
112.5 |
56.3 |
75.1 |
65.1 |
32.6 |
26.0 |
| 30.0 |
250.0 |
144.2 |
125.0 |
62.5 |
83.3 |
72.3 |
36.1 |
28.9 |
| 36.0 |
300.0 |
173.1 |
150.0 |
75.0 |
100.1 |
86.8 |
43.4 |
34.7 |
Controls are determined by finding the amperage
per line and multiplying by 1.25 factor.
How To Calculate Control Amperage
For single phase or two wire power supplies to heaters:
| Formula: |
Total Capacity (Watts)
Line Voltage |
= AMP Rating Per Role |
| Example: |
4000 (Watts)
240 Volts
|
= 16.67 Amps |
For three phase or three wire power supplied (Delta or Wye
connections) to heaters using a three-pole contactor:
| Formula: |
Total Capacity (Watts)
Line Voltage x 1.73 |
= AMP Rating Per Role |
| Example: |
4000 (Watts)
240 Volts x 1.73
|
= 9.63 Amps |
Try our automatic heater sizing programs.
|
