Electrical code: Difference between revisions

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{{Short description|Set of electrical building wiring regulations}}

{{Electrical Wiring Sidebar}}

An '''electrical code''' is a term for a set of regulations for the design and installation of [[electrical wiring]] in a building. The intention of such regulations is to provide standards to ensure electrical wiring systems are safe for people and property, protecting them from [[Electrical injury|electrical shock]] and fire hazards. They are usually based on a model code (with or without local amendments) produced by a national or international standards organisation.

Such wiring is subject to rigorous safety standards for design and installation. [[Wire]]s and [[electrical cable]]s are specified according to the circuit operating [[voltage]] and [[electric current]] capability, with further restrictions on the environmental conditions, such as ambient temperature range, moisture levels, and exposure to sunlight and chemicals. Associated circuit protection, control and distribution devices within a building's wiring system are subject to voltage, current and functional specification. To ensure both wiring and associated devices are designed, selected and installed so that they are safe for use, they are subject to wiring safety codes or regulations, which vary by locality, country or region.

The [[International Electrotechnical Commission]] (IEC) is attempting to harmonise wiring standards amongst member countries, but large variations in design and installation requirements still exist.

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{{Main|Electrical wiring in the United Kingdom}}

In the United Kingdom, wiring installations are regulated by the [[British Standard]] known as [[BS 7671]] ''Requirements for Electrical Installations: IET Wiring Regulations'', which are harmonised with IEC 60364. The first edition was published in 1882. BS 7671 is an industry standard and as such is not itself statutory, however legislation in the form of [[building regulations in the United Kingdom|UK Building Regulations]] requires that domestic installations conform to a safe standard, and official guidance accompanying this statutory regulation points to following BS 7671 as one way to comply.

BS 7671 is also used as a national standard by [[Mauritius]], [[St Lucia]], [[Saint Vincent and the Grenadines]], [[Sierra Leone]], [[Singapore]], [[Sri Lanka]], [[Trinidad and Tobago]], [[Uganda]] and [[Cyprus]].

===North America===

{{Main|Electrical wiring in North America}}

The first electrical codes in the United States originated in [[New York (state)|New York]] in 1881 to regulate installations of electric lighting. Since 1897 the US [[National Fire Protection Association]], a private non-profit association formed by insurance companies, has published the ''[[National Electrical Code (US)|National Electrical Code]]'' (NEC). States, counties or cities often include the NEC in their local building codes by reference along with local differences. The NEC is modified every three years. It is a consensus code considering suggestions from interested parties. The proposals are studied by committees of [[engineers]], [[tradesmen]], manufacturer representatives, fire fighters, and other invitees.

Since 1927, the [[Canadian Standards Association]] (CSA) has produced the Canadian ''Safety Standard for Electrical Installations'', which is the basis for provincial electrical codes. The CSA also produces the [[Canadian Electrical Code]], the 2006 edition of which references [[IEC 60364]] (''Electrical Installations for Buildings'') and states that the code addresses the fundamental principles of electrical protection in Section 131. The Canadian code reprints Chapter 13 of IEC 60364, but there are no numerical criteria listed in that chapter to assess the adequacy of any electrical installation.

Although the US and Canadian national standards deal with the same physical phenomena and broadly similar objectives, they differ occasionally in technical detail. As part of the [[North American Free Trade Agreement]] (NAFTA) program, US and Canadian standards are slowly converging toward each other, in a process known as harmonisation.

Mexico and Costa Rica follow the US [[National Electrical Code]].

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Venezuela and Colombia follow the US [[National Electrical Code]].

===India===

India is regulated by the so-called [[Central Electricity Authority Regulations]] (CEAR).

==Colour coding of wiring by region==

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===Europe===

From 1970 European countries started a process of harmonising their wiring colours, as several countries had chosen the same colour to denote different wires. The new harmonised colours were chosen mainly because no country had used them. Colours like pink, orange and turquoise were not available as they were deemed to be too close to other colours. Even so, there were unavoidable clashes. Blue was a phase conductor in the United Kingdom and Ireland, which delayed the adoption of the new colours for several decades. But flexible cable was changed pretty much instantly following pressure from manufacturers of appliances.<ref name="historyUK">{{Cite web |title=The history of colour identification of conductors |url=https://electrical.theiet.org/wiring-matters/years/2021/84-march-2021/the-history-of-colour-identification-of-conductors/|access-date=2024-07-10}}</ref><ref name="muckusmc">{{Cite web|url=https://forums.mikeholt.com/threads/wire-colour-coding-abroad.84611/ |title= Wire colour coding abroad|date= 25 February 2011}}</ref>

====Pre-harmonised European colours====

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| [[File:Color wire green.svg|80px|Green]] <br> [[File:Color wire yellow.svg|80px|Yellow]]

| [[File:Color wire grey.svg|80px|Grey]] <br> [[File:Color wire white.svg|80px|White]]

| [[File:Color wire red.svg|80px|Red]] <br> [[File:Color wire black.svg|80px|Black]]

|-

| {{NED}}

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| [[File:Color wire red yellow.svg|80px|Red/Yellow]]

|-

| {{POL}}<ref>{{cite tech report |author= Centralny Ośrodek Badawczo-Rozwojowy „Elektromontaż” |date= 1980-05-19 |title= Urządzenia elektroenergetyczne. Zasady doboru barw. Wymagania i badania. |url= https://bcpw.bg.pw.edu.pl/Content/11536/download/ |trans-title= Power electrical equipment. Colour selection rules. Requirements and testing. |type= Norma Branżowa [Industry Standard] |language=pl |id= BN-80/3008-03 |url-status=live |archive-url= http://web.archive.org/web/20250730141717/https://bcpw.bg.pw.edu.pl/Content/11536/download/ |archive-date= 2025-07-30|access-date= 2025-07-30 }}</ref>

| {{POL}}<ref>{{cite web |

| [[File:Color wire yellow.svg|80px|Yellow]]<br />[[File:Color wire green.svg|80px|Green]]<br />[[File:Color wire violett.svg|80px|Violet]]

url=https://ise.pl/phpbb3/viewtopic.php?t=13032|title=Dawne oraz pozaunijne oznaczenia przewodów, systemy sieci|access-date=17 July 2024}}</ref>

| [[File:Color wire orangeblue.svg|80px|Orange]] <br />[[File:Color wire white.svg|80px|WhiteBlue]]

| [[File:Color wire blackgreen.svg|80px|BlackLight green]]<br />[[File:Color wire yellow.svg|80px|Yellow]]

| [[File:Color wire green.svg|80px|Green]]

|-

| {{ITA}}<ref name="historyUK" />

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[[File:CENELEC.svg|thumb|CENELEC affiliated countries]]

As of March 2011, the European Committee for Electrotechnical Standardization (CENELEC) requires the use of green/yellow strippedstriped cables as protective conductors, blue as neutral conductors and brown as [[Single-phase electric power|single-phase]] conductors.<ref>{{cite web |title=New Cable Colour Code for Electrical Installations |url=https://elise.ema.gov.sg/safety/about.html#2 |publisher=Energy Market Authority |access-date=4 January 2016}}</ref>

{| class="wikitable" style="font-size:90%; width:auto; margin:0 0 1em;"

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|}

The use of strippedstriped green/yellow for earth conductors was adopted for its distinctive appearance to reduce the likelihood of dangerous confusion of safety earthing (grounding) wires with other electrical functions, especially by persons affected by red–green [[colour blindness]].

==== Sweden ====

In Sweden there is a notable exception for blue, where while the colour normally is used for neutral, it may be used as connecting wire between switches and between switch and fixture, as well as phase wire in a two-phase circuit, all under the condition that no neutral wire is used in the particular circuit.<ref>[https://www.sis.se/produkter/elektroteknik-24c2329a/allmant/ss4364000elektronisktformat/ SS-436 40 000 section 514.3. (Swedish)]</ref><ref>[https://www.elinstallatoren.se/2020/03/far-jag-anvanda-bla-ledare-som-tandtrad/ Cecilia Axelsson (Swedish)]</ref>

====United Kingdom====

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* Australia and New Zealand{{efn|name=iecasnzs|Australian and New Zealand wiring standards allow both Australian and European color codes.}}

* Italy

| [[File:Color wire brown.svg|80px|Brown]] [[File:Color wire black.svg|80px|Black]] [[File:Color wire grey.svg|80px|Grey]]<ref>Switzerland before 2005 also red and white for phases.</ref>
'''Prohibited:''' [[File:Color wire green yellow prohibited.svg|80px|Green/Yellow]]

| [[File:Color wire light blue.svg|80px|Light Blue]]{{efn|Sweden allow the use of blue for other purposes in circuits without a neutral, for instance two-phase with ground.}}

[[File:Color wire blue.svg|80px|Dark Blue]]<ref>Switzerland blue or light&nbsp;blue for neutral conductors</ref>

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== See also ==

* [[Electrical wiring]]

==References==

{{reflist}}

[[Category:Electrical safety]]