Electrical Wiring Color Codes for AC & DC – NEC & IEC

Wire and Cable Color Codes for AC Single-Phase, Three-Phase, and DC Circuits

Electrical engineers, contractors, traders, manufacturers, and especially electricians worldwide rely on different wiring color codes for wire and cable installations in industrial buildings and residential homes. These color codes are used for electrical distribution systems, and while some are mandatory, others are optional. Using the correct wiring color codes is crucial for identifying line, neutral, and ground wires, which saves time, simplifies maintenance and troubleshooting, and ensures the safety of those working on the system.

Wiring color codes vary by region and are designed to meet local standards and regulations for AC (Alternating Current) single-phase, AC three-phase, and DC (Direct Current) systems. Notable standards include:

This tutorial will discuss the wiring color codes for AC (single-phase and three-phase) and DC power systems based on the NEC and IEC standards. Many countries, including the UK (BS-7671), China, Russia, Hong Kong, Singapore, Ukraine, Belarus, Kazakhstan, Turkey, Israel, South Africa, Argentina, Malaysia, Saudi Arabia (KSA), and the UAE, have adopted the IEC wiring color codes. We will also examine the wiring color codes used in other regions, such as the US, Canada, the EU, Australia, New Zealand, Japan, India, Pakistan, and South Africa.

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Electrical Wiring Color Codes (NEC & IEC) - Single Phase & Three Phase (AC)

NEC Wiring Color Codes for AC – US & Canada

US – NEC (Single & Multi-Phase)

The mandatory colors for power wiring in the National Electrical Code (NEC) are Green, Bare, or Green/Yellow (a yellow stripe or band on green) for the protective ground (PG), and White (or alternatively Gray) for the neutral wire. However, any other colors, except those mentioned above, can be used for live (line or hot) wires. Meanwhile, the following colors are commonly adopted in local practice and used for line, neutral, and ground wires as follows.

Single Phase

120V AC – 1-Phase:

240V AC – 1-Phase:

This is also known as two phase or split phase AC supply but mostly called single phase supply.

*Good to Know: The colors used for hot wires are not explicitly specified in the NEC-2023 or any previous editions. However, they are commonly recommended and widely used by electricians as a general practice for safety and consistency.

Three Phase

Three Phase 208V AC:

Note: 208V Single Phase available between High Leg Line and Neutral / Ground.

Three Phase 277V & 480V (US) & 600V/347V (Canada) AC:

The following i.e. 277V and 480V AC (US) and 600V/347V (in Canada) supplies are used for industrial and high power equipment such as motors and  heaters in factories and production units.

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US AC Wiring Color Codes (NEC) - Single Phase & Three Phase

Canada – CEC (Single & Three-Phase) Wiring Color Codes 

Canadian Electrical Code “CEC” wiring color codes are similar in practice with National Electrical Code “NEC” except that White color is used for Neutral Wire and Green or bare conductor is used for protective ground. In some cases, the 1st and 2nd phase (lines) colors are in an inverse position as compared to NEC.

In short, the fowling wiring color codes are practiced in Canada.

Single Phase AC:

Mostly 120V and 240V (there is a second hot or phase wire in 240V single phase AC system).

Three Phase AC (Mandatory)

Wire colors used for 208V multiphase powers circuits

Three Phase AC (Isolated)

These colors are used for multi-phase 277 & 480V in Canada.

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Canada Wiring Color Codes - 1 & 3 Phase

NEC Wiring Color Codes for DC – US & Canada

There are some differences between AC and DC systems, so the wire color codes for DC differ slightly from those for AC in both NEC and IEC standards. These DC color codes are used for solar power and panels, batteries, vehicles, and other DC-powered equipment, such as computer data centers and wiring installations.

Similar to AC systems, the mandatory colors for grounded neutral wires are White or Gray, and the protective ground wire should be Green, bare conductor, or Green with a Yellow stripe. Any other colors may be used for hot (phase) wires. These codes apply to both AC and DC power circuits.

In the US, local practice typically uses Black for Phase 1 (Hot 1) or Line 1 (L1) and Red for Phase 2 (Hot 2) or Line 2 (L2). Additionally, the following wiring color codes are used in the US and Canada for two-wire grounded, two-wire ungrounded, and three-wire grounded DC power systems.

Two Wire Ungrounded DC Supply

Two Wire Grounded DC Supply

Three Wire Grounded DC Supply

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NEC - US & Canada DC Power Wiring Color Codes

IEC Wiring Color Codes for AC – UK , EU & Other Countries

As mentioned above, most of the Europe Union countries and UK, China, Russia, Hong Kong, Singapore, Ukraine, Belarus, Kazakhstan, Israel, Turkey, Argentina, South Africa, KSA (Saudi Arabia), UAE (United Arab Emirate) and Malaysia are following the IEC “International Electrotechnical Commission” wiring codes based on IEC 60445:2021. Keep in mind that some of the above mentioned countries such as UK, Russia & China etc. were using their own “Old wiring color codes” but now follow the IEC power circuit wire codes.

IEC NEW & OLD AC WIRING COLOR CODES - UK & EU NEW

UK & EU: IEC AC (Single & Three-Phase)

UK New (IEC) Wire Color Codes

Single Phase AC 230V

Three Phase AC 415+ V

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UK & EU AC Wiring Color Codes (IEC) - Single Phase & Three Phase

UK Old Wiring Color Codes

Prior to March 2004, the UK were following their own wiring color codes. These old wiring color codes are still used in the subcontinents including India, Pakistan, UAE and South Africa.

Single Phase AC 230V

Three Phase AC 415+ V

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UK Old & New IEC Wiring Color Codes

China & Russia Wiring Color Codes

China PRC & Russia (Old)

Single Phase AC

Three Phase AC – China

China PRC Wiring Color Codes for Single Phase and Three Phase

Russia New Wiring Color Codes

Russia was following the same wiring color codes as China before but they adapted the IEC with little bit changes i.e. in a three phase system, they may use purple or gray color instead of gray in IEC. As things are little bit changed in Russia, so one must follow the tester before going in the mess.

Single Phase AC

Three Phase AC

Russia Wiring Color Codes - Old & New

Australia & New Zealand Wiring Color Codes

Both Aussies and Kiwis are using the same wiring color codes according to AS/NZS 3000:2018 for single phase and three phase power circuits followed by IEC..

Single Phase AC

Three Phase AC

Australia & New Zealand Wiring Color Codes - Single & Three Phase

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Japan Wiring Color Codes

As the name suggests, Japan always does weird things. The single phase supply is 100V (Line to Neutral) and Three Phase supply is 200V (3 Lines, No Neutral). For wow reaction, Check the common neutral and 3rd Phase colors. They are the same i.e. white (Read the following note after the three phase codes for explanation). For electrical wiring installations, Japanese electricians use the following wiring color codes according AGN 203 – Japanese National Electrical Distribution System:

Single Phase AC

Three Phase AC

Japan Wiring Color Codes for 100 & 200V

Keep in mind that in case of three phase supply, there is no need for neutral wire here in Japan. So don’t panic with the “3rd Line” in three phases and the common Neutral as a White color.

India, Pakistan, UAE, KSA & South Africa

India, Pakistan, and other countries in the subcontinent, as well as the UAE (United Arab Emirates), KSA (Kingdom of Saudi Arabia), and South Africa (also known as the “Proteas”), traditionally followed the old UK wiring color codes. These include RYB (Red, Yellow, and Blue for three-phase systems) and Red and Black for phase and neutral, respectively. Although South Africa and others have now adopted the IEC standard, these older color codes are still in use in many regions.

India & Pakistan Wiring Color Codes - Single Phase & Three Phase

Single Phase 230V AC

Three Phase 415+ AC

South Africa Wiring Color Codes - Single & Three Phase

Israel Wiring Color Code

Some countries adapted the IEC wring codes with little bit modifications. Israel follow the IEC codes with the local practiced wiring are as follow:

Single Phase 230V AC

Three Phase 415+ AC

Indonesia Wiring Color Code

Single Phase AC Supply

Three Phase AC Supply

IEC Wiring Color Codes for DC – UK  & EU

The IEC DC wiring color codes are adopted from IEC AC wiring color codes based on IEC 60445:2021. These rules are applicable in the UK, EU and all other countries who follow the new IEC color codes instead of local and regional codes. The following IEC DC wiring color codes are used for Two-Wire Grounded, Two-Wire ungrounded and Three Wire grounded DC power systems.

IEC - DC POWER WIRING COLOR CODES - UK & EU

Two Wire Ungrounded DC Supply

Two Wire Grounded DC Supply

Three Wire Grounded DC Supply

The following tables shows the comparisons of different wire and cable color codes used in DC power circuits used by IEC and NEC.

NEC & IEC WIRING COLOR CODES FOR DC POWER

DC Wiring Color Codes in Other Countries

Australia & New Zealand

India, Pakistan & South Africa*:

* South Africa now follows IEC rules.

Israel:

Countries like China, Russia, Saudi Arabia (KSA), and the UAE now follow the IEC cable color codes for DC circuits. However, do not rely solely on the cable insulation colors in these regions, as electricians may still use both old and new color codes for AC and DC systems. It’s important to test with a multimeter or voltage tester to confirm the phase, neutral, as well as positive and negative wires.

Final Note: You have now learned the wiring color codes for DC and AC systems (including single-phase and three-phase circuits) as defined by IEC, NEC, and other regional standards. If you come across any unusual wiring color codes or would like to share the standards from your country or region, feel free to mention them in the comments below. We’ll be happy to update this post with your contributions. Thank you!

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