What are the Wire Color Codes by Country/Region?

Electrical wiring color codes are a standardized system used to identify and distinguish the different wires in an electrical circuit. Knowing these color codes is essential for ensuring safe and efficient electrical installations and maintenance. However, these color codes can vary depending on the country or region. In this article, we will examine how wiring color practices differ across various countries and regions.

It’s important to note that wiring color codes are specified according to different power distribution branch circuits. Therefore, to aid understanding, all the mentioned color code for electrical wiring is to transmit 3-phase AC current from the mains, which is closely related to the operation of 3-phase induction motors. In three-phase power systems, circuits will use five wires: 3 phase wires (L1, L2, L3), neutral wire (N), and earth/protective grounding (PE) wire.

European Three Phase Wire Color Codes

Most of Europe abides by IEC (International Electrotechnical Commission) wiring color codes for AC branch circuits. As per IEC, the wiring color codes for a three-phase five-wire system are defined as follows:

• Phase 1 or Line (L1): Brown
• Phase 2 or Line 2 (L2): Black
• Phase 3 or Line 3 (L3): Gray
• Neutral (N): Light Blue
• Protective Earth (PE) conductor: Green with Yellow stripe

Brown is used for the first phase (L1). The second phase (L2) is represented with black color, and gray is used for the third phase (L3) in some countries. In European wiring, blue is universally used to denote the neutral conductor (N). This wire completes the circuit and carries the return current. Throughout Europe, green with a yellow stripe is used for the protective conductor, commonly known as the earth or grounding wire (PE). This wire provides protection against electrical faults and ensures safety.

UK AC Power Circuit Wiring Color Codes

The UK’s current wiring color codes are harmonized with Europe’s power cable color coding, namely the IEC. According to this standard, the AC wiring color codes are as follows:

• Phase 1 or Line (L1): Brown
• Phase 2 or Line 2 (L2): Black
• Phase 3 or Line 3 (L3): Gray
• Neutral (N): Light Blue
• Protective Earth (PE) conductor: Green with Yellow stripe

Brown wires are used for live or phase conductors, black live wires can be found as line 2 in three-phase wiring, the grey live wire is the line 3 live wire, blue wires indicate neutral conductors, and green-and-yellow striped wires are employed for protective earthing or grounding.

US AC Power Circuit Wiring Color Codes

In North American countries, the wire color scheme is different from their European counterparts. In the United States, the standard wiring color code is established by the National Electrical Code (NEC). The color codes for AC power wires are as follows.

Typically, there are two electrical application settings to be considered in the US AC power circuit wiring color codes. In home and office environments, AC power systems commonly operate at voltages of 120, 208, or 240 volts. The following color codes are typically used in these settings:

U.S. Wire Color Code for 120V, 208V and 240V

• Phase 1: Black wire
• Phase 2: Red wire
• Phase 3: Blue wire (used in 208V three-phase systems)
• Neutral: White wire
• Ground: Green, green with a yellow stripe, or bare wire

Black wires are typically used for phase 1 live or hot conductors, the red wire is a phase 2 hot wire, the blue wire is a phase 3 hot wire, white wires indicate neutral conductors, and green, green with a yellow stripe or bare copper wires are employed for protective earthing or grounding.

U.S. Wire Color Code for 277V or 480V

Higher voltages such as 277 or 480 volts are commonly used in industrial settings to power heavy machinery and equipment. The color codes for AC power in industrial applications are as follows:

• Phase 1: Brown wire
• Phase 2: Orange wire
• Phase 3: Yellow wire
• Neutral: Gray wire
• Ground: Green, green with yellow stripe, or bare wire

In industrial three phase power supply, the combination of brown, orange and yellow wires are used as power conductors, gray wires are for neutral wires and green, green with yellow stripe or bare copper for ground wires.

Canada AC Power Circuit Wiring Color Codes

In Canada, the wire color coding follows the Canadian Electrical Code (CEC). The color code for AC power wiring is similar to the NEC in the United States.

• Phase 1: Red
• Phase 2: Black
• Phase 3: Blue
• Neutral: White or Gray
• Ground: Green or Green with Yellow Stripe

The three-phase lines from L1 to L3 are red, black and blue. The neutral is white. The protective ground is green or green with yellow stripe.

Electrical Wiring Colors in Asia

In Asia, wiring color codes can also vary significantly from one country to another.  The various countries have their own wiring color standards for electrical circuits. Here are some examples of wiring codes in Asian countries.

India AC Power Circuit Wiring Color Codes

In India, the standard for electrical wiring color code is based on the Indian Electricity Rules and the Indian Standard IS 694. In case of a three-phase power supply, the wire color codes include red for phase 1, yellow for phase 2, blue for phase 3, black for neutral conductor and green or green-and-yellow striped wires for protective earthing or grounding.

• Phase 1: Red
• Phase 2: Yellow
• Phase 3: Blue
• Neutral: Black
• Ground: Green or Green with Yellow Stripe

Russia AC Power Circuit Wiring Color Codes

In Russia, the electrical wiring colors for AC 3-phase systems adhere to specific standards to ensure safety and consistency in electrical installations. The preferred wiring color codes for a three-phase, five-wire system in Russia are:

• Phase 1 or Line (L1): Brown
• Phase 2 or Line 2 (L2): Black
• Phase 3 or Line 3 (L3): Gray
• Neutral (N): Light Blue
• Protective Earth (PE) conductor: Green with Yellow stripe

Brown wires are used for phase 1, black wires for phase 2, gray wire for phase 3, light blue wires for neutral connections and green with yellow stripe indicates protective earth conductors.

China AC Power Circuit Wiring Color Codes

The following wiring color codes are used in China for three-phase AC supplies:

• Phase 1 or Line (L1): Yellow
• Phase 2 or Line 2 (L2): Green
• Phase 3 or Line 3 (L3): Red
• Neutral (N): Light Blue or Black
• Protective Earth (PE) conductor: Green with Yellow stripe

In China, typical wire colors used in 3-phase wiring are yellow for Line 1, green for Line 2, Red for Line 3, light blue or black for neutral and green with yellow stripe for ground wires.

This is the ATO online store’s general guide to the electrical wire colour codes implemented in some major countries and regions. And again, all these color codes involved are standardized to differentiate between the different phases as well as neutral and grounding wires in a 3-phase electrical system.

It's important to note that these are general guidelines, and specific applications or local regulations may introduce additional colors or modifications, so it's essential to consult with local codes and standards when working with electrical wiring. If necessary, you can watch the following video to further understand.