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:
- The NEC (National Electrical Code) in the United States.
- The CEC (Canadian Electrical Code) in Canada.
- The IEC (International Electrotechnical Commission) standard, followed in the UK (including BS 7671), most European countries, and other nations such as Argentina.
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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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:
- BLACK = Phase , Hot or Line “L“
- WHITE = Neutral “N”
- GREEN, BARE or GREEN / YELLOW = Ground Conductor (Protective Ground) “PG“
240V AC – 1-Phase:
This is also known as two phase or split phase AC supply but mostly called single phase supply.
- BLACK = Phase 1 , Hot 1 or Line 1 “L1”
- RED = Phase 2 , Hot 2 or Line 2, “L2”
- WHITE = Neutral “N”
- GREEN, BARE or GREEN / YELLOW = Ground “PG”
*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:
- BLUE = Phase 1 , Hot 1 or Line 1 “L1”
- ORANGE = Phase 2 , Hot 2 or Line 2 “L2” (Orange color used for High Leg or Power Leg Delta)
- BLACK = Phase 3 , Hot 3 or Line 3 “L3”
- WHITE = Neutral “N”
- GREEN, BARE or GREEN / YELLOW = Ground “PG”
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.
- BROWN = Phase 1 , Hot 1 or Line 1 “L1”
- ORANGE = Phase 2 , Hot 2 or Line 2 “L2”
- YELLOW = Phase 3 , Hot 3 or Line 3 “L3”
- GRAY = Neutral “N”
- GREEN, BARE or GREEN / YELLOW = Ground “PG”
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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).
- RED or BLACK= Phase , Hot or Line, (In case of two lines) “L1 or L2”
- WHITE = Neutral “N”
- GREEN, BARE or GREEN / YELLOW = Ground Conductor “PG”
Three Phase AC (Mandatory)
Wire colors used for 208V multiphase powers circuits
- RED = Phase 1 or Line 1, “L1”
- BLACK = Phase 2 or Line 2 “L2”
- BLUE = Phase 3 or Line 3 “L3”
- WHITE or GRAY = Neutral “N”
- GREEN, BARE or GREEN / YELLOW = Ground “PG”
Three Phase AC (Isolated)
These colors are used for multi-phase 277 & 480V in Canada.
- ORANGE = Phase 1 or Line 1 “L1”
- BROWN = Phase 2 or Line 2 “L2”
- YELLOW = Phase 3 or Line 3 “L3”
- WHITE or GRAY = Neutral “N”
- GREEN, BARE or GREEN / YELLOW = Ground “PG”
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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
- RED = +Ve (L+)
- BLACK = -Ve (L-)
- GREEN, BARE CONDUCTOR or GREEN / YELLOW = Protective Ground “PG”.
Two Wire Grounded DC Supply
- RED = +Ve of a -Ve Grounded Circuit (L+)
- WHITE = -Ve of a -Ve Grounded Circuit (N)
- WHITE = +Ve of a +Ve Grounded Circuit (N)
- BLACK = -Ve of a +Ve Grounded Circuit (L-)
- GREEN, BARE CONDUCTOR or GREEN / YELLOW = Protective Ground “PG”.
Three Wire Grounded DC Supply
- RED = +Ve (L+)
- WHITE = Mid-Wire as Center Tapped (N)
- BLACK = -Ve (L-)
- GREEN, BARE CONDUCTOR or GREEN / YELLOW = Protective Ground “PG”.
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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.
UK & EU: IEC AC (Single & Three-Phase)
UK New (IEC) Wire Color Codes
Single Phase AC 230V
- BROWN = Phase , Hot or Line, (L)
- BLUE = Neutral (N)
- GREEN / YELLOW = Earth Conductor “Protective earth” (PE)
Three Phase AC 415+ V
- BROWN = Phase 1 or Line, (L1)
- BLACK= Phase 2 or Line 2, (L2)
- GRAY= Phase 3 or Line 3, (L3)
- BLUE = Neutral (N)
- GREEN / YELLOW = Earth Conductor “Protective earth” (PE).
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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
- RED = Phase , Hot or Line, (L)
- BLACK = Neutral (N)
- GREEN / YELLOW = Earth Conductor “Protective earth” (PE)
Three Phase AC 415+ V
- RED = Phase 1 or Line, (L1)
- YELLOW = Phase 2 or Line 2, (L2)
- BLUE = Phase 3 or Line 3, (L3)
- BLACK = Neutral (N)
- GREEN / YELLOW = Earth Conductor “Protective earth” (PE)
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China & Russia Wiring Color Codes
China PRC & Russia (Old)
Single Phase AC
- YELLOW = Phase , Hot or Line, (L)
- SKY BLUE or BLACK = Neutral (N)
- GREEN / YELLOW = Earth Conductor “Protective earth” (PE)
Three Phase AC – China
- YELLOW = Phase 1 or Line, (L1)
- GREEN = Phase 2 or Line 2, (L2)
- RED = Phase 3 or Line 3, (L3)
- LIGHT BLUE or BLACK = Neutral (N)
- GREEN / YELLOW = Earth Conductor “Protective earth” (PE)
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
- BROWN = Phase , Hot or Line, (L)
- BLACK = Neutral (N)
- GREEN / YELLOW = Earth Conductor “Protective earth” (PE)
Three Phase AC
- BROWN = Phase 1 or Line, (L1)
- BLACK = Phase 2 or Line 2, (L2)
- GRAY or PURPLE = Phase 3 or Line 3, (L3)
- LIGHT BLUE = Neutral (N)
- GREEN / YELLOW = Earth Conductor “Protective earth” (PE)
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
- RED or BROWN = Phase , Hot or Line, (L)
- BLACK or SKY BLUE = Neutral (N)
- GREEN or GREEN / YELLOW = Earth Conductor “Protective earth” (PE)
Three Phase AC
- RED or BROWN = Phase 1 or Line, (L1)
- WHITE = Phase 2 or Line 2, (L2)
- BLUE = Phase 3 or Line 3, (L3)
- BLACK or LIGHT BLUE = Neutral (N)
- GREEN or GREEN / YELLOW = Earth Conductor “Protective earth” (PE).
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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
- BLACK or RED = Phase , Hot or Line, (L)
- WHITE = Neutral (N)
- GREEN = Earth Conductor “Protective earth” (PE)
Three Phase AC
- BLACK = Phase 1 or Line, (L1)
- RED = Phase 2 or Line 2, (L2)
- WHITE = Phase 3 or Line 3, (L3)
- WHITE = Common Neutral (N) (Used in Two Lines System Only)
- GREEN = Earth Conductor “Protective earth” (PE)
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.
Single Phase 230V AC
- RED = Phase , Hot or Line, (L)
- BLACK = Neutral (N)
- YELLOW / GREEN = Earth Conductor “Protective earth” (PE)
Three Phase 415+ AC
- RED = Phase 1 or Line, (L1)
- YELLOW = Phase 2 or Line 2, (L2)
- BLUE = Phase 3 or Line 3, (L3)
- BLACK = Common Neutral (N) (Used in Two Lines System Only)
- YELLOW / GREEN = Earth Conductor “Protective earth” (PE)
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
- BROWN = Phase , Hot or Line, (L)
- BLUE = Neutral (N)
- YELLOW / GREEN = Earth Conductor “Protective earth” (PE)
Three Phase 415+ AC
- BROWN (Or L1 Marking Sleeve) = Phase 1 or Line, (L1)
- BROWN (ORANGE STRIP) (Or L2 Marking Sleeve) = Phase 2 or Line 2, (L2) (Or L2 Marking Sleeve)
- BROWN (BLACK STRIP) (Or L3 Marking Sleeve) = Phase 3 or Line 3, (L3)
- BLUE = Common Neutral (N)
- YELLOW / GREEN = Earth Conductor “Protective Earth” (PE)
Indonesia Wiring Color Code
Single Phase AC Supply
- RED or BLACK = Phase , Hot or Line, (L)
- BLUE = Neutral (N)
- YELLOW / GREEN = Earth Conductor “Protective earth” (PE)
Three Phase AC Supply
- RED = Phase 1 or Line, (L1 or R)
- YELLOW = Phase 2 or Line 2, (L2 or S)
- BLACK = Phase 3 or Line 3, (L3 or T)
- BLUE = Common Neutral (N)
- YELLOW / GREEN = Earth Conductor “Protective Earth” (PE)
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.
Two Wire Ungrounded DC Supply
- BROWN = +Ve (L+)
- GRAY = -Ve (L-)
- GREEN / YELLOW = Protective Earth “PE”.
Two Wire Grounded DC Supply
- BROWN = +Ve of a -Ve Grounded Circuit (L+)
- BLUE = -Ve of a -Ve Grounded Circuit (M)
- BLUE = +Ve of a +Ve Grounded Circuit (M)
- GRAY = -Ve of a +Ve Grounded Circuit (L-)
- GREEN / YELLOW = Protective Earth “PE”.
Three Wire Grounded DC Supply
- BROWN = +Ve (L+)
- BLUE = Mid-Wire as Center Tapped (N)
- GRAY = -Ve (L-)
- GREEN / YELLOW = Protective Earth “PE”.
The following tables shows the comparisons of different wire and cable color codes used in DC power circuits used by IEC and NEC.
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DC Wiring Color Codes in Other Countries
Australia & New Zealand
- RED or BROWN = +Ve (L+)
- BLACK or Light BLUE = -Ve (L-)
- GREEN or GREEN / YELLOW = Protective Earth “PE”.
India, Pakistan & South Africa*:
- RED = +Ve (L+)
- BLACK = -Ve (L-)
- GREEN / YELLOW = Protective Earth “PE”.
* South Africa now follows IEC rules.
Israel:
- BROWN = +Ve (L+)
- BLUE = -Ve (L-)
- GREEN / YELLOW = Protective Earth “PE”.
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!
Resources
- How to Find the Proper Size of Wire & Cable Based on NEC and IEC?
- How to Wire 120V & 240V Main Panel? Breaker Box Installation
- How to Determine the Right Size Capacity of a Subpanel?
- How to Wire a Subpanel? Main Lug Installation for 120V/240V
- How to Size a Load Center, Panelboards and Distribution Board?
- How to Wire Single-Phase, 230V Consumer Unit with RCD? IEC, UK & EU
- How to Wire 1-Phase Split Load Consumer Unit? – RCD+RCBO
- How to Wire Combo of 3 & 1-Φ, 400V/230V Distribution Board?
- How to Wire a Three Phase, 400V Distribution Board? IEC & UK
- How to Wire a Garage Consumer Unit?
- How to Wire a UK 3-Pin Plug? Wiring a BS1363 Plug
- How to Wire a UK 3-Pin Socket Outlet? Wiring a BS1363 Socket
- Wiring of the Distribution Board with RCD – Single Phase Home Supply
- SMD Resistor Codes: How to Find the Value of SMD Resistors
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