Wire Conventions
In many cases, the color of a wire's insulation determines it's function. The specifics tend to differ from country to country, though many things stay consistent, such as the color of ground wires.
The table below shows the colors for AC power in Canada. [2]
| Function | Label | Color |
|---|---|---|
| Protective Ground | PG | Green/green-yellow |
| Neutral | N | White |
| Line, single phase | L | Black or Red |
| Line 1 | L1 | Red |
| Line 2 | L2 | Black |
| Line 3 | L3 | Blue |
| A green-yellow ground wire [1] |
|---|
|
Wire gauge refers to the diameter of a wire. A wider gauge leads to a higher current capacity, also referred to as ampacity, which allows it to carry more current before overheating [4]. For alternating current, the effects of skin effect also increase as the gauge increases in size, which leads to greater attenuation of the signal [5]. There are multiple standards for wire gauge used. In Canada, you will run into American wire gauge, sometimes referred to as Browne and Sharpe gauge and abbreviated as AWG. In AWG, increase in gauge number represents a decrease of around 12% of the wire's diameter and around 26% in it's area. The largest gauge is 0000, followed by 000, 00 and 0. These are sometimes denoted 4/0, 3/0 2/0 and 1/0 respectively. From there on it counts up from 1 to 40, 40 being the smallest. All sizes are measured in inches. There also exist the Standard wire gauge, Circular Mil area and Birmingham wire gauge. Standard wire gauge is used in Britain and is similar to American wire gauge. The largest size is 7/0, which counts down to 1/0. From there on out, it goes from 1 to 50, 50 being the smallest size. [6]
Below is a table with some of the values for AWG [6]
| American wire gauge | Diameter (inches) | Diameter (millimeters) | Area (mm2) | Ampacity for copper wire (A) | Max Frequency for 100% skin depth on copper wire (Hz) |
|---|---|---|---|---|---|
| 0000 or 4/0 | 0.46 | 11.684 | 107 | 302 | 125 |
| 000 or 3/0 | 0.4096 | 10.40384 | 85 | 239 | 160 |
| 00 or 2/0 | 0.3648 | 9.26592 | 67.4 | 190 | 200 |
| 0 or 1/0 | 0.3249 | 8.25246 | 53.5 | 150 | 250 |
| 1 | 0.2893 | 7.34822 | 42.4 | 119 | 325 |
| 2 | 0.2576 | 6.54304 | 33.6 | 94 | 410 |
| 3 | 0.2294 | 5.82676 | 26.7 | 75 | 500 |
| 4 | 0.2043 | 5.18922 | 21.2 | 60 | 650 |
| 5 | 0.1819 | 4.62026 | 16.8 | 47 | 810 |
| 6 | 0.1620 | 4.1148 | 13.3 | 37 | 1100 |
| 7 | 0.1443 | 3.66522 | 10.5 | 30 | 1300 |
| 8 | 0.1285 | 3.2639 | 8.37 | 24 | 1650 |
| 9 | 0.1144 | 2.90576 | 6.63 | 19 | 2050 |
| 10 | 0.1019 | 2.58826 | 5.26 | 15 | 2600 |
| 15 | 0.0571 | 1.45034 | 1.65 | 4.7 | 8250 |
| 20 | 0.0320 | 0.8128 | 0.518 | 1.5 | 27000 |
| 25 | 0.0179 | 0.45466 | 0.162 | 0.457 | 85000 |
| 30 | 0.010 | 0.254 | 0.0509 | 0.142 | 270000 |
| 35 | 0.0056 | 0.14224 | 0.016 | 0.044 | 870000 |
| 40 | 0.0031 | 0.07874 | 0.00501 | 0.0137 | 2900000 |
| American wire gauge [3] |
|---|
|
References
| [1] | A. K, Home Earth Australia Rod. Wikimedia, 2006. |
| [2] | “Wiring color codes,” All About Circuits. [Online]. Available: https://www.allaboutcircuits.com/textbook/reference/chpt-2/wiring-color-codes/. [Accessed: 19-Oct-2021]. |
| [3] | WIRE GAUGE AMERCAIN STD 0-36. Grainger. |
| [4] | R. Regole, “What is wire ampacity and why its calculation is critical,” Iconn Systems, 29-Aug-2016. [Online]. Available: https://www.iconnsystems.com/blog/ampacity. [Accessed: 16-Nov-2021]. |
| [5] | R. Hranac, “Skin effect and skin depth,” Broadband Library, 22-May-2020. [Online]. Available: https://broadbandlibrary.com/skin-effect-and-skin-depth/. [Accessed: 16-Nov-2021]. |
| [6] | “American wire gauge conductor size table” Solaris shop. [Online]. Available: https://www.solaris-shop.com/content/American%20Wire%20Gauge%20Conductor%20Size%20Table.pdf. [Accessed: 24-Oct-2021]. |