Long-distance transmission of electrical power can result in voltage drops due to several factors, including resistance in transmission lines, inductive reactance, and the skin effect.
To mitigate voltage drops in long-distance transmission, several strategies can be employed, such as:
Regular maintenance and monitoring of transmission lines, as well as ongoing upgrades to infrastructure and technology, are essential to ensuring the reliable and efficient transmission of electrical power over long distances.
To calculate the voltage drop, input the current, length, material, AWG, and type of circuit. The calculator will use the appropriate formula to determine the voltage drop.
For AC Single-phase and DC circuits:
$$ V_{drop} = \frac{2 \times I \times \rho \times L}{A} $$
For Three-phase circuits:
$$ V_{drop} = \frac{\sqrt{3} \times I \times \rho \times L}{A} $$
Let's calculate the voltage drop for a copper wire (AWG 10) with a current of 15 A, a length of 50 meters, and a single-phase AC circuit.
Given:
Using the formula for AC Single-phase:
$$ V_{drop} = \frac{2 \times 15 \times 1.68 \times 10^{-8} \times 50}{5.261 \times 10^{-6}} $$
Calculating the voltage drop:
$$ V_{drop} = \frac{2 \times 15 \times 1.68 \times 10^{-8} \times 50}{5.261 \times 10^{-6}} = 4.9 \text{ V} $$
Use the table below to find the cross-sectional area and resistance for different AWG sizes:
AWG | Cross-Sectional Area (mm²) | Resistance (Ohms per 1000m) |
---|---|---|
0000 (4/0) | 107.22 | 0.1608 |
000 (3/0) | 85.029 | 0.2028 |
00 (2/0) | 67.431 | 0.2557 |
0 (1/0) | 53.475 | 0.3224 |
1 | 42.408 | 0.4066 |
2 | 33.631 | 0.5127 |
3 | 26.67 | 0.6464 |
4 | 21.151 | 0.8152 |
5 | 16.773 | 1.028 |
6 | 13.302 | 1.296 |
7 | 10.549 | 1.634 |
8 | 8.366 | 2.061 |
9 | 6.634 | 2.599 |
10 | 5.261 | 3.277 |
11 | 4.172 | 4.132 |
12 | 3.309 | 5.211 |
13 | 2.624 | 6.571 |
14 | 2.081 | 8.285 |
15 | 1.65 | 10.448 |
16 | 1.309 | 13.174 |
17 | 1.038 | 16.612 |
18 | 0.823 | 20.948 |
19 | 0.6527 | 26.415 |
20 | 0.5176 | 33.308 |
21 | 0.4105 | 42.001 |
22 | 0.3255 | 52.962 |
23 | 0.2582 | 66.784 |
24 | 0.2047 | 84.213 |
25 | 0.1624 | 106.19 |
26 | 0.1288 | 133.9 |
27 | 0.1021 | 168.85 |
28 | 0.081 | 212.92 |
29 | 0.0642 | 268.48 |
30 | 0.0509 | 338.55 |
31 | 0.0404 | 426.9 |
32 | 0.032 | 538.32 |
33 | 0.0254 | 678.8 |
34 | 0.0201 | 855.96 |
35 | 0.016 | 1,079.3 |
36 | 0.0127 | 1,361 |
37 | 0.01 | 1,716.2 |
38 | 0.007967 | 2,164.1 |
39 | 0.006318 | 2,728.9 |
40 | 0.00501 | 3,441.1 |
Material | Conductivity, σ (Ω⋅m)⁻¹ | Resistivity, ρ (Ω⋅m) | Temperature Coefficient, α (°C)⁻¹ |
---|---|---|---|
Silver | 6.29×10⁷ | 1.59×10⁻⁸ | 0.0038 |
Copper | 5.95×10⁷ | 1.72×10⁻⁸ | 0.0039 |
Gold | 4.10×10⁷ | 2.44×10⁻⁸ | 0.0034 |
Aluminum | 3.77×10⁷ | 2.65×10⁻⁸ | 0.0039 |
Tungsten | 1.79×10⁷ | 5.60×10⁻⁸ | 0.0045 |
Iron | 1.03×10⁷ | 9.71×10⁻⁸ | 0.0065 |
Platinum | 0.94×10⁷ | 10.60×10⁻⁸ | 0.0039 |
Steel | 0.50×10⁷ | 20.00×10⁻⁸ | 0.006 |
Wire Gauge | 5W (0.2 A) | 10W (0.42 A) | 20W (0.83 A) | 30W (1.3 A) | 40W (1.7 A) | 50W (2.1 A) | 60W (2.5 A) | 70W (2.9 A) | 80W (3.3 A) | 90W (3.75 A) | 100W (4.2 A) |
---|---|---|---|---|---|---|---|---|---|---|---|
22 AWG | 107 ft. | 52 ft. | 27 ft. | 17 ft. | 13 ft. | 10.5 ft. | 9 ft. | 7.5 ft. | 6.8 ft. | 6 ft. | 5.3 ft. |
20 AWG | 170 ft. | 85 ft. | 43 ft. | 27 ft. | 21 ft. | 17 ft. | 14 ft. | 12 ft. | 11 ft. | 9 ft. | 8 ft. |
18 AWG | 270 ft. | 134 ft. | 68 ft. | 45 ft. | 33 ft. | 27 ft. | 22 ft. | 19 ft. | 17 ft. | 15 ft. | 14 ft. |
16 AWG | 430 ft. | 215 ft. | 109 ft. | 72 ft. | 54 ft. | 43 ft. | 36 ft. | 31 ft. | 27 ft. | 24 ft. | 22 ft. |
14 AWG | 680 ft. | 345 ft. | 174 ft. | 115 ft. | 86 ft. | 69 ft. | 57 ft. | 49 ft. | 43 ft. | 39 ft. | 36 ft. |
12 AWG | 1090 ft. | 539 ft. | 272 ft. | 181 ft. | 135 ft. | 108 ft. | 90 ft. | 77 ft. | 68 ft. | 61 ft. | 56 ft. |
10 AWG | 1730 ft. | 784 ft. | 397 ft. | 263 ft. | 197 ft. | 158 ft. | 131 ft. | 112 ft. | 98 ft. | 97 ft. | 82 ft. |
Wire Gauge | 5W (0.42 A) | 10W (0.83 A) | 20W (1.7 A) | 30W (2.5 A) | 40W (3.3 A) | 50W (4.16 A) | 60W (5 A) |
---|---|---|---|---|---|---|---|
22 AWG | 27 ft. | 14 ft. | 7 ft. | 4.5 ft. | 3.5 ft. | 2.8 ft. | 2.2 ft. |
20 AWG | 43 ft. | 18 ft. | 9 ft. | 6 ft. | 5 ft. | 4 ft. | 3 ft. |
18 AWG | 68 ft. | 34 ft. | 17 ft. | 11 ft. | 8 ft. | 6 ft. | 5 ft. |
16 AWG | 110 ft. | 54 ft. | 27 ft. | 18 ft. | 13 ft. | 10 ft. | 9 ft. |
14 AWG | 170 ft. | 86 ft. | 43 ft. | 29 ft. | 21 ft. | 17 ft. | 14 ft. |
12 AWG | 275 ft. | 134 ft. | 68 ft. | 45 ft. | 34 ft. | 27 ft. | 22 ft. |
10 AWG | 430 ft. | 199 ft. | 99 ft. | 66 ft. | 49 ft. | 39 ft. | 33 ft. |
This condition causes the load to work harder with less voltage pushing the current. The National Electrical Code recommends limiting the voltage drop from the breaker box to the farthest outlet for power, heating, or lighting to 3 percent of the circuit voltage.
The acceptable voltage drop is typically within 5%, but it can vary based on electrical system requirements, load conditions, cable types, length, and national/regional electrical standards.