Guide to Building Electrical Wiring Color Codes

ELECTRICAL WIRING COLOR CODES - Electrical Wiring Color Codes & Conventions for 120V or 240V A/C Circuits in Buildings - Tables of Electrical wiring color code conventions for 120V & 240V AC circuits in buildings in the U.S., Canada, the U.K. & the I.E.C.
ELECTRICAL OUTLET, HOW TO ADD & WIRE - separate article
ELECTRICAL SPLICES, how to make - separate article
Questions & Answers about Electrical Wiring Color Codes & Conventions for 120V or 240V A/C Circuits in Buildings
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This article describes the electrical wiring color code conventions for 120V or 240V AC circuit wiring in buildings in Canada, the U.S., the U.K. and the I.E.C. Quoting from authoritative codes & standards for each region we provide a table summarizing the current and prior wiring color code conventions used by electricians in building wiring. For each color code table we include authority citations and links to sources of codes, books, standards and wiring guidelines. We point out with photo-examples that while wire color code theory is nice and all that, in the real world of working on existing buildings, wires are not always reliably color-coded and colors may in fact be impossible to discern. Some of the wire color images here were adapted from data provided by the Malta Resources Authority's excellent document on Harmonisation of Wiring Colour Codes - cited below.

Building Electrical Wiring Color Codes & Conventions for 120V or 240V A/C Circuits

This new type NM-B 14-3 electrical wire has color coded conductors that are easy to spot and understand:

Black - use for line voltage or "hot" wire
Red - a second line voltage or "hot" wire
White - neutral
Bare - protective ground

But as we illustrate below, on some older buildings spotting any color at all in the wiring insulation or jacket can be difficult or even impossible.

120V / 240V A/C Electrical Wiring Color Codes & Conventions: U.S.
Wire Insulation Color	Alternative Wire Colors	Label	Function	Comments
Black		L	Line voltage, single phase
Black	Brown	L1	Line voltage, 3-phase
Red		L	Line voltage, single phase, second "hot" wire	Often used to indicate switched power
Red	Orange	L2	Line voltage, 3-phase
White	Gray	N	Neutral	In wiring a switch the electrician may use the white wire as a second hot conductor and will mark each end of the wire with black electrical tape - shown below.
Blue	Yellow	L3	Line voltage, 3-phase
Green		PG		Protective ground wire
Green + Yellow		PG		Protective ground wire
Bare		PG		Protective ground wire, no insulation
Orange	Yellow	L		"Excepted voltage", these wires may be hot when main disconnect is switched off"
Notes & wiring color code standard sources: 1. National Electrical Code 2011 (NEC) - see http://www.nfpa.org/ (adopted in all 50 U.S. states) 2. UL508A, Section 66.5.3 & 66.9 3. NFPA 79, Chapter 13 - see http://www.nfpa.org/ Some sources include red with white tracer line = switched neutral

Antique wiring color coded in jackeing or insulation (C) Daniel Friedman

On older wiring such as this rubber and fabric-jacketed household wiring from a U.S. home, figuring out what the heck the wire colors are can itself be a challenge.

Look closely at the fabric covering of the two wiring strands in our photo.

The upper wire is the "white" or neutral wire.

The lower wire, whose fabric insulation is black with red and white tracer threads is the "black" or hot wire.

But sometimes there is no clear color distinction between the two wires: you'll need to trace the wiring and use a DMM or VOM to figure out which wire is "hot" and which is neutral or ground.

120V / 240V A/C Electrical Wiring Color Codes & Conventions: Canada
Wire Insulation Color	Alternative Wire Colors	Label	Function	Comments
Black		L	Line voltage, single phase
Red		L	Line voltage, single phase, second "hot" wire
White		N	Neutral
Black		L1	Line voltage, 3-phase
Red		L2	Line voltage, 3-phase
Blue		L3	Line voltage, 3-phase
Green		PG		Protective ground wire
Green + Yellow stripe		PG		Protective ground wire
Bare		PG		Protective ground wire
Notes: 1. 2012 Canadian Electrical Code (CEC) - see http://shop.csa.ca Mississauga Office 5060 Spectrum Way, Suite 100 Mississauga, Ontario Canada, L4W 5N6 Toll-Free: (800) 463-6727 Tel: (416) 747-4000 Fax: (416) 747-2473 Edmonton Office 1707-94 Street North West Edmonton, Alberta Canada, T6N 1E6 Main: (780) 450-2111 Sales: (780) 490-2007 Fax: (780) 490-2059

This knob-and-tube electrical wiring photo has useful information for the electrician or building inspector.

First we can see that if we're in luck, the fabric portion of the wiring insulation may be intact and may clearly show that one conductor is white (neutral) and the other black (hot). With age the white insulation may have become tan or even brownish in color.

Second I'm a bit nervous about how that white wire is stripped back and is in contact with the hot black wire (arrow).

Finally, of course there is no protective ground on this circuit - we've got just two wires with which to contend.

120V / 240V A/C Electrical Wiring Color Codes & Conventions: U.K. United Kingdom
Wire Insulation Color	Alternative or Older-Usage Wire Colours	Label	Function	Comments
Brown	Red	L	Line voltage, single phase
Blue	Black	N	Neutral
Brown	Red	L1	Line voltage, 3-phase
Black	Yellow	L2	Line voltage, 3-phase
Gray	Blue	L3	Line voltage, 3-phase
Green + Yellow stripe		PE		Protective earth conductor
Cream		PE		Functioning earth conductor
Notes: new wiring colour codes replaced existing red & black phase & neutral conductors (left) with brown and blue (right) beginning in 2005. Where extensions or new work can result in mixed wiring colours, a warning must be fixed near the distribution board stating: CAUTION: this installation has wiring colours to two versions of BS 7671. Great care should be taken before undertaking extension, alteration or repair that all conductors are correctly identified. Regulating authority, IEC AC I.E.E. Regulations (UK Standard BS 7671:2001) Requirements for Electrical Installations, IEE Wiring Regulations, Sixteenth Edition Amendment No. 2: AMD 14905, March 2004 "New Fixed Wiring Colours - A Practical Guide", www.nicelc.org.uk "The IEE, ELectrician's Guide to the building regulations, including Approved Document P: Electrical Safety in Dwellings, Chapter 11" Malta Resources Authority, "Harmonisation of Wiring Colour Codes, Practical Guidelines", http://mra.org.mt www.i.e.e.org/cablecolours Three phase wiring colour codes & color changes are shown just below:

This wiring ... well don't even think about figuring this out by color codes. Someone has just grabbed a piece of yellow wire and a blue wire, left an open splice, and jury-rigged something (not shown in our photo).

But when you see obviously amateur electrical--wiring like this it's a red flag to watch out, asking "what else did this fellow wire in this building?"

120V / 240V A/C Electrical Wiring Color Codes & Conventions: Europe - IEC
Wire Insulation Color	Alternative Wire Colors	Label	Function	Comments
Brown	Black	L	Line voltage, single phase
Blue	Blue	N	Neutral
Brown	Black	L1	Line voltage, 3-phase
Black	Brown	L2	Line voltage, 3-phase
Gray	Brown Black	L3	Line voltage, 3-phase
Green + Yellow stripe		PE		Protective Earth wire
Notes: Regulating authority, IEC AC

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Technical Reviewers & References

Related Topics, found near the top of this page suggest articles closely related to this one.

The 2008 NEC National Electrical Code (ISBN 978-0877657903) Online Access LINK (you'll need to sign in as a professional or as a visitor)
The 2008 Residential Wiring Code, a subset of the 2008 NEC, can be understood through Mastering the NEC at http://www.2008nec.com/shopping/pgm-more_information.php?id=18
NFPA - the National Fire Protection Association can be found online at www.nfpa.org
[2] N. Srinivasan, MSEE, is a senior member of IEEE with 30 years experience in the electrical industry. Mr. Srinivasan is in Vienna VA.
[3] Louis P. Babin generously contributed technical editing about the effects of doubling ampacity in an electrical circuit (September 2007)
[4] Digisnap DSA-500 snap-around digital multimeter, A.W. Sperry Instruments Inc., 2150 Joshua's Path, Suite 202, Hauppage NY 11788, Tel: 800-645-5398, Email: cat@awsperry.com, Website: www.awsperry.com
[5] Fluke Corporation, 6920 Seaway Blvd, Everett, WA 98203, USA, PO Box 9090 Everett, Washington 98206, Tel: +1(425) 347-6100, Technical support: 1(800) 44-FLUKE (1(800) 443-5853), Website: www.fluke.com,
Fluke Europe B.V, PO Box 1186 Eindhoven, The Netherlands, Tel: +31 (0)40 2 675 200 +31 (0)40 2 675 222, Website: www.fluke.eu
- Fluke India: TTL India Pvt. Ltd. (A Fluke Company), Deodhar Center, 424, Marol Maroshi Road, Andheri (E), Mumbai, 400076, Tel: 1 800 209 9110, Email: info.india@fluke.com, Website: http://www.fluke.com/fluke/inen/products/Digital-Multimeters.htm
- Digital 287/289 Digital Multimeter, Users Manual, retrieved 9/5/21, original source: http://assets.fluke.com/manuals/287_289_umeng0200.pdf, [copy on file as Fluke_287_289_umeng0200.pdf]
[6] Simpson Electric, P.O. Box 99, 520 Simpson Avenue, Lac du Flambeau, WI 54538-0099 Tel: 715-588-3311, customer service: 715-588-3947, Email: support@simpsonelectric.com, Website: www.simpsonelectric.com/
- Simpson 260® Series 6XLM Volt-Ohm-Milliammeter Instruction Manual, retrieved 9/5/2012, original source: http://www.simpsonelectric.com/uploads/File/datasheets/260-6xlm.pdf, [copy on file as Simpson_260-6xlm.pdf]
[7] tif 300cc Tic Tracer voltage detector, Tif Instruments Inc., 9101 NW 7th Avenue, Miami, Florida 33150
[8] Greenlee® GT-16 adjustable voltage detector, Greenlee Textron Inc., Website: greenlee.com, Tel: 800-435-0786 , Email: echsupport@greenlee.textron.com,
[9] Jensen VOMs, no longer available
[10] Mastech VOMs and DMMs (made in China), Shanghai Hihua V&A Instrument Company, 881 Ye Cheng Road Jia Ding District, Shanghai 201821, China, Email: mastech@vip.sina.com, Tel: +86 21 69523164　+86 21 69523225, Website: http://www.mastech.com.cn/
[11] Equus Multimeters by Innova, Equus Products, Inc., 17352 Von Karman Ave., Irvine, CA 92614, U.S.A., Tel: 714-241-6800, Website: http://www.equus.com/
[12] Actron DMMs & VOMs, Website: http://www.actron.com/
[13] ExTech DMMs & VOMs, ExTech Corp. a FLIR company, Extech Instruments Corporation, 9 Townsend West, Nashua, NH 03063, U.S.A., Email: support@extech.com, Tel: 877-239-8324 Option 3, Website: http://www.extech.com
[15] Dr. Jess Aronstein, consulting engineer, Poughkeepsie NY, 1991 protune@aol.com
[16] Rex Cauldwell, master electrician and contributor to the Journal of Light Construction on electrical topics
[17] New York State Central Hudson Gas and Electric Company, G&E/1-2/85 consumer safety pamphlet
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Building Electrical Wiring Color Codes & Conventions for 120V or 240V A/C Circuits

120V / 240V A/C Electrical Wiring Color Codes & Conventions: U.S.

120V / 240V A/C Electrical Wiring Color Codes & Conventions: Canada

120V / 240V A/C Electrical Wiring Color Codes & Conventions: U.K. United Kingdom

120V / 240V A/C Electrical Wiring Color Codes & Conventions: Europe - IEC

Frequently Asked Questions (FAQs) about color code conventions for building electrical wiring

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Technical Reviewers & References

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

Guide to Building Electrical Wiring Color Codes