Editing Three-phase electric power (section)

== Color codes ==
{{See also|Electrical wiring#Colour code}}
Conductors of a three-phase system are usually identified by a color code, to facilitate balanced loading and to assure the correct phase rotation for [[electric motor|motors]]. Colors used may adhere to International Standard [[IEC 60446]] (later [[IEC 60445]]), older standards or to no standard at all and may vary even within a single installation. For example, in the U.S. and Canada, different color codes are used for grounded (earthed) and ungrounded systems.

{| class="wikitable"
! rowspan=2 colspan=2 | Country
! colspan=6 | Phases<ref group="note" name="note9">Many labelling systems exist for phases, some having additional meaning, such as: {{nowrap|H1, H2, H3}}; {{nowrap|A, B, C}}; {{nowrap|R, S, T}}; {{nowrap|U, V, W}}; {{nowrap|R, Y, B}}.</ref>
! rowspan=2 colspan=2 | Neutral, <br/>N<ref group="note" name="note10">Also, grounded conductor.</ref>
! rowspan=2 colspan=3 | Protective earth, <br/>PE<ref group="note" name="note11">Also, earth, or grounding conductor.</ref>
|-
! colspan=2 | L1
! colspan=2 | L2
! colspan=2 | L3
|-
| colspan=2 | Australia and New Zealand (AS/NZS{{nbsp}}3000:2007 Figure{{nbsp}}3.2, or IEC{{nbsp}}60446 as approved by AS:3000)
| style="padding:0.2em 0.6em; background:red;" |      || Red, or brown<ref group="note" name="note1">In Australia and New Zealand, active conductors can be any color except green/yellow, green, yellow, black, or light blue. Yellow is no longer permitted in the 2007 revision of wiring code ASNZS 3000.  European color codes are used for all IEC or flex cables such as extension leads, appliance leads etc. and are equally permitted for use in building wiring per AS/NZS 3000:2007.</ref>
| style="padding:0.2em 0.6em; background:white;" |    || White;<ref group="note" name="note1" /> {{abbr|prev.|previously}} yellow
| style="padding:0.2em 0.6em; background:darkblue;" | || Dark blue, or grey<ref group="note" name="note1" />
| style="padding:0.2em 0.6em; background:black;" |    || Black, or blue<ref group="note" name="note1" />
| style="background:green; padding:0.2em 0.3em;" |    || style="padding:0.2em; background:yellow;" | || Green/yellow-striped (installations prior to 1966: green)
|-
| rowspan=2 | Canada
| Mandatory<ref>{{cite book |date=2015 |title=C22.1-15 – Canadian Electrical Code, Part I: Safety Standard for Electrical Installations |publisher=Canadian Standards Association |edition=23rd |isbn=978-1-77139-718-6 |page=Rule 4–038 |no-pp=y}}</ref>
| style="background:red;" |   || Red<ref group="note" name="note2">In Canada the high leg conductor in a high-leg delta system is always marked red.</ref>
| style="background:black;" | || Black
| style="background:blue;" |  || Blue
| style="background:white;" | || White, or grey
| style="background:green;" | || style="padding:0.2em; background:yellow;" | || Green, perhaps yellow-striped, or uninsulated
|-
| Isolated systems<ref>{{cite book |date=2015 |title=C22.1-15 – Canadian Electrical Code, Part I: Safety Standard for Electrical Installations |publisher=Canadian Standards Association |edition=23rd |isbn=978-1-77139-718-6 |page=Rule 24–208(c) |no-pp=y}}</ref>
| style="background:orange;" |  || Orange
| style="background:#7f462c;" | || Brown
| style="background:yellow;" |  || Yellow
| style="background:white;" |   || White, or grey
| style="background:green;" |   || style="padding:0.2em; background:yellow;" | || Green perhaps yellow-striped
|-
| colspan=2 | European [[CENELEC]] ([[European Union]] and others; since April 2004, [[IEC 60446]], later IEC{{nbsp}}60445-2017), United Kingdom (since 31{{nbsp}}March 2004), Hong Kong (from July 2007), Singapore (from March 2009), Russia (since 2009; GOST{{nbsp}}R{{nbsp}}50462), Argentina, Ukraine, Belarus, Kazakhstan, South Korea (from Jan. 2021)
| style="background:#7f462c;" | || Brown
| style="background:black;" |   || Black
| style="background:gray;" |    || Grey
| style="background:blue;" |    || Blue
| style="background:green;" |   || style="padding:0.2em; background:yellow;" | || Green/yellow-striped<ref group="note" name="note3">The international standard green-yellow marking of protective-earth conductors was introduced to reduce the risk of confusion by [[color blindness|color blind]] installers. About 7% to 10% of men cannot clearly distinguish between red and green, which is a particular concern in older schemes where red marks a live conductor and green marks protective earth or safety ground.</ref>
|-
| colspan=2 | Older European (prior to [[IEC 60446]], varied by country)<ref group="note" name="note4">In Europe, there still exist many installations with older colors but, since the early 1970s, all new installations use green/yellow earth according to [[IEC 60446|IEC{{nbsp}}60446]]. (E.g. phase/neutral & earth, German: black/grey & red; France: green/red & white; Russia: red/grey & black; Switzerland: red/grey & yellow or yellow & red; Denmark: white/black & red.</ref>
|-
| colspan=2 | UK (before April 2006), Hong Kong (before April 2009), South Africa, Malaysia, Singapore (before February 2011)
| style="background:red;" |    || Red
| style="background:yellow;" | || Yellow
| style="background:blue;" |   || Blue
| style="background:black;" |  || Black
| style="background:green;" |  || style="padding:0.2em; background:yellow;" | || Green/yellow-striped (before c. 1970: green)
|-
| colspan=2 | India
| style="background:red;" |    || Red
| style="background:yellow;" | || Yellow
| style="background:blue;" |   || Blue
| style="background:black;" |  || Black
| style="background:green;" |  || style="padding:0.2em; background:yellow;" | || Green, perhaps yellow-striped
|-
| colspan=2 | Chile – NCH 4/2003 
| style="background:blue;" |   || Blue
| style="background:black;" |  || Black
| style="background:red;" |    || Red
| style="background:white;" |  || White
| style="background:green;" |  || style="padding:0.2em; background:yellow;" | || Green, perhaps yellow-striped
|-
| colspan=2 | Former USSR (Russia, Ukraine, Kazakhstan; before 2009), People's Republic of China<ref group="note" name="note8">Note that while China officially uses phase 1: yellow, phase 2: green, phase 3: red, neutral: blue, ground: green/yellow, this is not strongly enforced and there is significant local variation.</ref> (GB{{nbsp}}50303-2002 Section{{nbsp}}15.2.2)
| style="background:yellow;" | || Yellow
| style="background:green;" |  || Green
| style="background:red;" |    || Red
| style="background:#09f;" |   || Sky blue
| style="background:green;" |  || style="padding:0.2em; background:yellow;" | || Green/yellow-striped
|-
| colspan=2 | Norway (before CENELEC adoption)
| style="background:black;" |   || Black
| style="background:white;" |   || White/grey
| style="background:#7f462c;" | || Brown
| style="background:blue;" |    || Blue
| style="background:yellow;" |  || style="padding:0.2em; background:green;" | || Yellow/green-striped; {{abbr|prev.|previously}} yellow or uninsulated
|-
| colspan=2 | Norway <ref group="note" name="note 9">According to the guidance in NEK 400-5-51, Section 514.3 NEK:2022 the recommended order in Norway is L1: BLACK, L2: BROWN, and L3: GRAY. However other order may be used. As for when this was implemented it may have been NEK400:2002. PE shall be GREEN/YELLOW according to 514.3.3</ref>
| style="background:black;" |   || Black
| style="background:#7f462c;" |   || Brown
| style="background:gray" | || Grey
| style="background:blue;" |    || Blue
| style="background:green;" |   || style="padding:0.2em; background:yellow;" | || Green/yellow-striped
|-
| rowspan="5" | United States<ref group="note" name="note6">Since 1975, the U.S. National Electric Code has not specified coloring of phase conductors. It is common practice in many regions to identify 120/208{{nbsp}}V (wye) conductors as black, red, and blue, and 277/480{{nbsp}}V (wye or delta) conductors as brown, orange, yellow. In a 120/240{{nbsp}}V delta system with a 208{{nbsp}}V high leg, the high leg (typically B phase) is always marked orange, commonly A phase is black and C phase is either red or blue. Local regulations may amend the N.E.C. The U.S. National Electric Code has color requirements for grounded conductors, ground, and grounded-delta three-phase systems which result in one ungrounded leg having a higher voltage potential to ground than the other two ungrounded legs.</ref>
| 120, 208, or 240 V
| style="background:black;" | || Black
| style="background:red;" |   || Red
| style="background:blue;" |  || Blue
| style="background:white;" | || White
| colspan=2 style="background:gold;" | || Bare Conductor (no insulation)
|-
| 277 or 480 V
| style="background:#7f462c;" | || Brown
| style="background:orange;" |   || Orange
| style="background:yellow;" |  || Yellow
| style="background:gray;" | || Gray
| colspan=2 style="background:gold;" | || Bare Conductor (no insulation)
|-
| rowspan="3" | Alternate Practices (Delta with tapped winding)
| rowspan="2" style="background:black;" | || rowspan="2" | Black
| rowspan="2" style="background:orange;" | || rowspan="2" | Orange
(High-Leg<ref group="note" name="note12">Must be the high leg, if it is present.</ref>)
| style="background:red;" |  || Red
| rowspan="2" style="background:white;" | || rowspan="2" | White
| rowspan="2" style="background:green;" | || rowspan="2" style="padding:0.2em; background:yellow;" | || rowspan="2" | Green or Yellow/green-striped or no insulation
|-
| style="background:blue;" |  || Blue
|}