View source for IEC 60446

{{1r|date=March 2017}}{{Use British (Oxford) English|date=January 2012}}
The international standard '''IEC 60446'''  ''Basic and safety principles for man-machine interface, marking and identification - Identification of equipment terminals, conductor terminations and conductors'' was a standard published by the [[Organization:International Electrotechnical Commission|International Electrotechnical Commission]] (IEC) that defined basic safety principles for identifying electrical conductors by colours or numerals, for example in electricity distribution wiring.  The standard has been withdrawn; the fourth edition (IEC 60446:2007) was merged in 2010 into the fifth edition of [[IEC 60445]] along with the fourth edition, IEC 60445:2006.

== Permitted colours ==
The standard permits the following colours for identifying conductors:

: black, brown, red, orange, yellow, green, blue, violet, grey, white, pink, and turquoise.

(The colours green and yellow on their own are only permitted where confusion with the colouring of the green/yellow protective conductor is unlikely. Combinations of the above colours are permitted, but green and yellow should not be used in any of these combinations other than as green/yellow for the protective conductor.)

== Use of colours ==

=== Neutral or mid-point conductor ===
If a circuit includes a neutral or midpoint conductor, then it should be identified by a [[Image:Color wire light blue.svg|50px]] <span style="color:#4444ff;">'''blue'''</span> colour (preferably light blue). Light blue is the color used to identify intrinsically safe conductors, and must not be used for any other type of conductor.

=== AC phase conductors ===
The preferred colours for AC phase conductors are:
* L1: [[Image:Color wire brown.svg|50px]] <span style="color:brown;">'''brown'''</span>
* L2: [[Image:Color wire black.svg|50px]] <span style="color:black;">'''black'''</span>
* L3: [[Image:Color wire grey.svg|50px]] <span style="color:grey;">'''grey'''</span>
For a single AC phase: [[Image:Color wire brown.svg|50px]] <span style="color:brown;">'''brown'''</span><ref>{{cite web |url=http://www.sourceiec.com/Catalogs/Chapter%2013%20EX%20Wiring%20Methods.pdf |title=Archived copy |access-date=2016-01-25 |url-status=bot: unknown |archive-url=https://web.archive.org/web/20170412062322/http://www.sourceiec.com/Catalogs/Chapter%2013%20EX%20Wiring%20Methods.pdf |archive-date=12 April 2017 }}</ref>

=== Protective conductor ===
The colour combination [[Image:Color wire green yellow.svg|50px]] '''<span style="color:green;">green</span>'''/'''<span style="color:#cccc00;">yellow</span>''' is always and exclusively used to identify the protective conductor. On any 15&nbsp;mm length of the conductor, one of these two colours should cover between 30% and 70% of the area and the other the remaining area.

=== Protective earth and neutral (PEN) conductor ===
Insulated PEN conductors (combined protective earth + neutral in [[Engineering:Earthing system#Types of TN networks|TN–C systems]]) should be marked:
* either [[Image:Color wire green yellow.svg|50px]] '''<span style="color:green;">green</span>'''/'''<span style="color:#cccc00;">yellow</span>''' along their entire length with <span style="color:#4444ff;">'''light blue'''</span> markings at their ends,
* or [[Image:Color wire light blue.svg|50px]] <span style="color:#4444ff;">'''light blue'''</span> along their entire length with '''<span style="color:green;">green</span>'''/'''<span style="color:#cccc00;">yellow</span>''' markings at the ends.
The cable must have a cross section of 16&nbsp;mm{{sup|2}} (5&nbsp;AWG) or greater.

=== United States, Canada and Japan ===
The three countries United States, Canada and Japan are mentioned in a note in the standard for using different colours:
* [[Image:Color wire white.svg|50px]] '''white''' or 50px '''<span style="color:#808080;">natural gray</span>''' for mid-wire or neutral conductor (instead of [[Image:Color wire light blue.svg|50px]] <span style="color:#4444ff;">'''light blue'''</span>)
* [[Image:Color wire green.svg|50px]] '''<span style="color:green;">green</span>''' for the protective conductor (instead of [[Image:Color wire green yellow.svg|50px]] '''<span style="color:green;">green</span>'''/'''<span style="color:#cccc00;">yellow</span>''')

=== United Kingdom ===
British Standard [[Engineering:BS 7671|BS 7671]]:2001 Amendment No 2:2004 adopted the IEC 60446 colours for fixed wiring in the United Kingdom [https://web.archive.org/web/20060502232823/http://www.iee.org/Publish/Wireregs/cablecol.cfm], with the extension that [[Image:Color wire gray.svg|50px]] <span style="color:#808080;">'''grey'''</span> can also be used for line conductors, such that three colours are available for three-phase installations. This extension is expected to be adopted across Europe and may even find its way into a future revision of IEC 60446.

== Marking ==
Where conductors are in addition identified by letters and numbers, then:
* letters to be used come from Latin character set,
* numbers must be written in Arabic numerals, digits 6 and 9 must be underlined ({{Underline|6}} and {{Underline|9}}),
* and a few symbols like + and − can be used.
Green-and-yellow conductors must not be marked.

Examples: L1, L2, L3, N, L+, L−, M, 35, 1{{Underline|6}}

== References ==
{{Reflist}}
== External links ==
* [https://webstore.iec.ch/publication/16226 IEC 60446:2007]: ''Basic and safety principles for man-machine interface, marking and identification – Identification of conductors by colours or numerals'', [[Organization:International Electrotechnical Commission|International Electrotechnical Commission]], Geneva.
* [https://webstore.iec.ch/publication/2156 IEC 60445:2010]: ''Basic and safety principles for man-machine interface, marking and identification - Identification of equipment terminals, conductor terminations and conductors'', International Electrotechnical Commission, Geneva.
* Paul Cook: [https://web.archive.org/web/20081227124949/http://www.theiet.org/publishing/wiring-regulations/colour/col-harm.cfm Harmonised colours and alphanumeric marking]. IEE Wiring Matters, Spring 2006.
* {{IEC|60446}}
{{List of IEC standards}}
[[Category:IEC standards|#60446]]
[[Category:Electrical wiring]]

{{Sourceattribution|IEC 60446}}