IEC 60446

From HandWiki

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 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 The standard has been withdrawn; the fourth edition (IEC 60446:2007) was merged in 2010 into the fifth edition of IEC 60445 along with the fourth edition, IEC 60445:2006.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 Color wire light blue.svg 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: Color wire brown.svg brown
  • L2: Color wire black.svg black
  • L3: Color wire grey.svg grey

For a single AC phase: Color wire brown.svg brown[1]

Protective conductor

The colour combination Color wire green yellow.svg 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 Color wire green yellow.svg green/yellow along their entire length with light blue markings at their ends,
  • or Color wire light blue.svg 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:

  • Color wire white.svg white or 50px natural gray for mid-wire or neutral conductor (instead of Color wire light blue.svg light blue)
  • Color wire green.svg green for the protective conductor (instead of Color wire green yellow.svg 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 Color wire gray.svg 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

External links