IEC 60446
This article relies largely or entirely on a single source. (March 2017) |
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 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 The standard has been withdrawn; the fourth edition (IEC 60446:2007) was merged in 2010 into the fifth edition of IEC 60445 along with the fourth edition, IEC 60445:2006.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 blue 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: brown
- L2: black
- L3: grey
For a single AC phase: brown[1]
Protective conductor[]
The colour combination green/yellow is always and exclusively used to identify the protective conductor. On any 15 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 TN–C systems) should be marked:
- either green/yellow along their entire length with light blue markings at their ends,
- or light blue along their entire length with green/yellow markings at the ends.
The cable must have a cross section of 16 mm2 (5 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:
- white or natural gray for mid-wire or neutral conductor (instead of light blue)
- green for the protective conductor (instead of green/yellow)
United Kingdom[]
British Standard BS 7671:2001 Amendment No 2:2004 adopted the IEC 60446 colours for fixed wiring in the United Kingdom [1], with the extension that grey 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 (6 and 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, 16
References[]
- ^ "Archived copy" (PDF). Archived from the original on 12 April 2017. Retrieved 2016-01-25.CS1 maint: archived copy as title (link) CS1 maint: bot: original URL status unknown (link)
External links[]
- IEC 60446:2007: Basic and safety principles for man-machine interface, marking and identification – Identification of conductors by colours or numerals, International Electrotechnical Commission, Geneva.
- 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: Harmonised colours and alphanumeric marking. IEE Wiring Matters, Spring 2006.
- "IEC 60446" at International Electrotechnical Commission
- IEC standards
- Electrical wiring