Usage of the ungrounded system is discouraged for safety. He makes no recommendation for ungrounded power system colors. The recommendations in the Table below are by Wiles. However, common practice (per local electrical inspectors) is for the first hot (live or active) wire to be black and the second hot to be red. Hot (active) wires may be any other colors except these.

The protective ground must be bare, green, or green-yellow striped. US DC power: The US National Electrical Code (for both AC and DC) mandates that the grounded neutral conductor of a power system be white or grey. The IEC color standard for DC power cables is listed in Table below, adapted from Table 2, Cook. IEC, DC: DC power installations, for example, solar power and computer data centers, use color-coding which follows the AC standards. Three-phase lines are red, black, and blue. The neutral is white, the hot (live or active) single-phase wires are black, and red in the case of a second active. The protective ground is green or green with a yellow stripe. Conductors larger than #6 AWG are only available in black and are color taped at the ends.Ĭanada: Canadian wiring is governed by the CEC (Canadian Electric Code). Black, red, and blue are used for 208 VAC three-phase brown, orange, and yellow are used for 480 VAC. The colors adopted as a local practice are shown in the Table below. In principle, any other colors except these may be used for the power conductors. US, AC: The US National Electrical Code only mandates white (or grey) for the neutral power conductor and bare copper, green, or green with a yellow stripe for the protective ground. For adding new colored wiring to existing old colored wiring see Cook. The Table below lists these along with the obsolete domestic color codes. UK, AC: The United Kingdom now follows the IEC AC wiring color codes. The protective ground wire (listed as green-yellow) is green with a yellow stripe. The older color codes in the table reflect the previous style which did not account for proper phase rotation.

IEC, AC: Most of Europe abides by IEC (International Electrotechnical Commission) wiring color codes for AC branch circuits. In that case, local custom dictates the “optional” wire colors. In other jurisdictions, only a few conductor colors are so codified.

In some jurisdictions, all wire colors are specified in legal documents. Wiring for AC and DC power distribution branch circuits are color-coded for the identification of individual wires.

Old power transformer wire color code