IEC 60446

From Wikipedia, the free encyclopedia

International standard IEC 60446 defines basic safety principles for identifying electrical conductors by colours or numerals, for example in electricity distribution wiring.

Contents 1 Permitted colours 2 Use of colours 2.1 Neutral or mid-point conductor 2.2 AC phase conductors 2.3 Protective conductor 2.4 PEN conductor 2.5 United States, Canada and Japan 2.6 United Kingdom 3 Numbering 4 References

[edit] Permitted colours

The standard permits the following colours for identifying conductors:

black, brown, red, orange, yellow, green, blue, violet, grey, white, pink, 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.)

[edit] Use of colours

[edit] Neutral or mid-point conductor

If a circuit includes a neutral or mid-point conductor, then it should be identified by a blue colour (preferably light blue). Light blue must not be used for any other type of conductor.

[edit] AC phase conductors

The preferred colours for AC phase conductors are black and brown.

[edit] 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.

[edit] PEN conductor

Insulated PEN conductors 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.

[edit] 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 grey for mid-wire or neutral conductor (instead of light blue)
• green for the protective conductor (instead of green-and-yellow)

[edit] 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 live 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 in a future revision of IEC 60446.

[edit] Numbering

Where conductors are in addition identified by numbers, then these numbers must be written in Arabic numerals, digits 6 and 9 must be underlined, and green-and-yellow conductors must not be numbered.

[edit] References

• IEC 60446:1999: Basic and safety principles for man-machine interface, marking and identification — Identification of conductors by colours or numerals. International Electrotechnical Commission, Geneva.

• Paul Cook: Harmonised colours and alphanumeric marking. IEE Wiring Matters, Spring 2006.