color standarts for 3 phase AC

In Europe (EN 60446, HD 308S2):

Phase R - brown Phase Y - black Phase B - grey Neutral - blue PE - green-and-yellow

In UK (BS 7671), till 31.3.2004 (overlap till 31.3.2006):

Phase R - red Phase Y - yellow Phase B - blue Neutral - black PE - green-and-yellow

From 1.4.2004 (overlap till 31.3.2006, compulsory from 1.4.2006:

same as Europe

See my posting of Mon, 14 Jul 2003 21:46:51 +0100 (BST)

The IEE has established a "Cable colour changes" website at

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which includes links to guidance documents and the draft amendment to BS7671 Identification by Colours.

Reply to
Bill Lyons
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The US (NEC) does not really specify other than that the ground shall be green or green/yellow and the neutral shall be white or grey. The unofficial convention is black/red/blue for 208/240v and Brown/Orange/Yellow for 480v.

277v L/N loads on 480v wye are usually Violet with grey neutrals. The high leg on a centertapped deltas SHALL be orange. This may cause confusion where there are 240 CT delta and 480 present so the "BOY" convention can't be used there.

I suppose we need an international standard but we can't even agree on how we mark our thermometers and rulers.

Reply to


Does anybody know what the IEC (which number of standart?) color standards are for 3 phase mains (for Europe, for US, for UK)?

For information, in Russia use - L1-yellow L2-green L3-red N-blue PE-yellow-green PEN - blue-yellow-green


Reply to
Igor Nikanov

For the USA electricians tried to make Brown, Orange, Yellow the color code for 3-phase 480 volts in the 1987 NEC. They submitted over 500 proposals to change the NEC, based on many personal near misses and actual electrical shocks. One Code making panel member that represented NECA, the National Electrical Contractors Association, voted against the change and won. His argument was that the change would require too many reels of wire to be carried on trucks and that NECA would comply, but others would not. So today we have a watered down version of for identifying circuits in Section

210.4 Multiwire Branch Circuits: D) Identification of Ungrounded Conductors. Where more than one nominal voltage system exists in a building, each ungrounded conductor of a multiwire branch circuit, where accessible, shall be identified by phase and system. This means of identification shall be permitted to be by separate color coding, marking tape, tagging, or other approved means and shall be permanently posted at each branch-circuit panelboard.
Reply to
Gerald Newton

what is EN 60446 and HD 308S2 ?

what is R Y B ?


Reply to
Igor Nikanov

As an interesting side note Motorola uses Black Red Blue for 277-480 and Brown Yellow Orange for 120-208

Reply to

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