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WIRING CAPACITY TABLE
MAXIMUM kW LOAD PER CIRCUIT |
AMPERES CAPACITY |
||||||
SINGLE PHASE OR DC |
THREE PHASE BALANCED |
FUSE |
SWITCH |
CIRCUIT |
AWG. |
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120V |
240V |
208V |
240V |
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1.4 |
2.8 |
4.2 |
4.9 |
15 |
30 |
15 |
12 |
3.8 |
5.7 |
6.6 |
20 |
30 |
20 |
12 |
|
5.7 |
8.5 |
9.9 |
30 |
30 |
30 |
10 |
|
7.6 |
11.5 |
13.3 |
40 |
60 |
40 |
8 |
|
9.6 |
14.3 |
16.6 |
50 |
60 |
50 |
6 |
|
11.5 |
17.2 |
19.9 |
60 |
60 |
60 |
6 |
|
13.4 |
20.1 |
23.2 |
70 |
100 |
70 |
4 |
|
15.3 |
23.0 |
26.6 |
80 |
100 |
80 |
4 |
|
17.2 |
25.9 |
29.9 |
90 |
100 |
90 |
2 |
|
19.2 |
28.7 |
33.2 |
100 |
100 |
100 |
2 |
|
21.1 |
31.6 |
36.5 |
110 |
200 |
110 |
2 |
|
24.0 |
35.9 |
41.5 |
125 |
200 |
125 |
1 |
|
28.8 |
43.1 |
49.8 |
150 |
200 |
150 |
0 |
|
ELECTRICAL "PIE CHART" FORMULAS
P=Power(Watts) I=Current(Amps) E=Supply Voltage R=Resistance(Ohms)
If you know any two factors, such as Power/Watts(P) and Voltage(E) you can divide P by E and get I (the current pull. If you know the Current Pull/Amps (I) and the Voltage(E) you can multiply I x E and get the Wattage. Both formula charts work the same, divide the top factor by one of the lower factors or multiply the bottom factors by one another to get the top factor.
THREE PHASE CURRENT PULL
To figure Amps per line of a three phase appliance if you know, or figure the single phase current pull using the pie charts above, then all you have to do is DIVIDE THE SINGLE PHASE CURRENT PULL BY 1.73 and the result will be the CURRENT PULL PER LINE FOR A THREE PHASE UNIT.
The formula would be: WATTS ÷ VOLTAGE = AMPS ÷ 1.73 = CURRENT PULL PER LINE