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  • wire colors?

    WE all know here that black, White, and green are the accepted/standard colors for a 120VAC power cord or house wiring.
    Black is "hot", White is "neutral", and Green is "Ground".

    Red is often found as the "leader" in three way switches etc.etc.

    SO....... Outside the USA looking at European 120VAC power cords shipped here you have different colors: Brown is "hot", Blue is "neutral", and green with a yellow stripe is "ground".

    Why were these colors selected for the various potentials [blk=hot etc.]
    Why are the color codes not the same [yet similar] in other countries?
    How did red get selected for the leader wire and not, say "yellow or orange"?

    I understand some folks are color blind and that may play a role in the wire color code hierarchy.

    Anyone with some historical insight to how these colors came to be?

    Oh, and just to confuse the conversation..DC uses a different color code where Red is + and black is - and green is ground! I can't tell you how many folks confuse the AC wire color code and the DC color code!!!!!

    Cactus Man

  • #2
    Re: wire colors?

    Hi Cactus, This answers some of your questions but not all:

    (http://www.en.wikipedia.org/wiki/Ele...(United_States)

    Red is often used as the "traveler" in a three-way switch circuit, but just because it is red, do not assume it is a switch leg traveler. Red is the second color used in AC home wiring for a hot, and any other color (orange, purple, blue, etc.,) is also a hot. You'll find this a lot when pulling THHN into conduit. The green with yellow stripe is also a universal ground color, along with solid green and bare copper wire which sparkies will refer to as the "green" wire even though it is not sheathed.
    Here (http://www.repeater-builder.com/tech...ower-info.html) is another pretty good treatise on wire colors. The only thing I'd differ with in this article is he says to tape your marrets after you make them up. Most inspectors do NOT want your marrets taped because that can hide whether the splice is made up correctly inside of it. They want to be able to pull on one wire to see if it will come out or not. Just because a wire is green, do not assume it is the ground. Same goes for whites and colored wires. Test them first with a meter and see if green is ground, white neutral and black hot. Also make use of a tick tracer to first check to make sure power is off. Then double check with your meter before sticking your fingers inside the J-box. Hope this helps. Will keep looking for more historical perspective.
    Jim Don

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    • #3
      Re: wire colors?

      To really make people scratch their heads, I hear that over in China it's common practice that white is hot and black is neutral. (power cords) I did read about backwards connected portable generators made in China making it to the USA resulting in some disasters, and yet they are still being sold as best I can tell. Such is not acceptable in my book. We the people of the USA must demand better.

      There really needs to be worldwide standards but I doubt I'll live long enough to see them implemented.

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      • #4
        Re: wire colors?

        Unless I am mistaken, I believe Europe uses a diffrent color scheme because of the diffent voltages and frequency they operate on over there. I have wired up several tanning beds from Europe and as soon as I pull the control covers I can identify that it was made in Europe by the color codeing and know to look to see what voltage ratings it has and whether it can run on 60 hz as is. I prefer that Europe keep a diffrent set of colors, It would be chaos in my opinion if they used the same colors for a diffrent system.

        Jeff

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        • #5
          Re: wire colors?

          Originally posted by piette View Post
          I prefer that Europe keep a different set of colors, It would be chaos in my opinion if they used the same colors for a different system. Jeff
          Very good idea, but anything shipped to the USA for our use needs to be to our standards regardless of where it was made. Other areas need their standards but please let's work on worldwide standards as well.

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          • #6
            Re: wire colors?

            Originally posted by Woussko View Post
            Very good idea, but anything shipped to the USA for our use needs to be to our standards regardless of where it was made. Other areas need their standards but please let's work on worldwide standards as well.
            I understand what you are saying, but the fact is that products come to this country from Europe and are designed for European electrical systems. I would hate to see the day that a machine designed for a different voltage and frequency comes wired using our color system and the guy wiring it doesn't realize what he is wiring. We can't simply require that the rest of the world change to using 120 volt 60 hhz electrical systems. That would be an enormous undertaking to replace everything around the world to be our system. By the same standards, why then does Europe not require us to change to meet their standards?


            Jeff

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            • #7
              Re: wire colors?

              Not sure you understand me.

              I have in mind that anything from anywhere that's made for use here and to our standards would need to be made so it meets all of them. (Our standards if for sale in the USA)

              If we make a product to export then it needs to be made totally to the standards for where's it will be sold regardless of where that might be.

              The idea is for there to be zero confusion and no having to deal with special requirements for items either exported or imported.

              Examples: If something is for sale here then no matter where made, it has to be made to our standards. If made here for sale in say Germany then we have to comply with their standards.

              Time I go back to sleep in The Woussko Hut
              Last edited by Woussko; 03-10-2008, 05:24 AM.

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              • #8
                Re: wire colors?

                The european standard of blue/brown is quite recent. Until before around 2004 neutral was black and hot was red.

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                • #9
                  Re: wire colors?

                  That is right, the UK is now changing to the newer EU codes.
                  I have in one country in the past year that uses green/yellow as a phase when using 3 phase.

                  Scott

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                  • #10
                    Re: wire colors?

                    Originally posted by scsmith View Post
                    That is right, the UK is now changing to the newer EU codes.
                    I have in one country in the past year that uses green/yellow as a phase when using 3 phase.

                    Scott
                    It all ready old news they did change that about 5 years ago and i am oringally from France so i know their crazy system.

                    the green/yellow stripe is always earth never used as phase conductor at all.

                    [ this is the http://www.electrical-contractor.net...e/1#Post148731 { copy and paste this } international wire colours codes ]

                    some of oddball colurs will supried you if not carefull.

                    Merci, Marc

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                    • #11
                      Re: wire colors?

                      So, um, why not take a giant leap towards world harmony and safety and move the US to the European wire colour standard just as the UK has done? Don't bother answering, its sort of a rhetorical question.

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                      • #12
                        Re: wire colors?

                        Originally posted by ToolGirl View Post
                        So, um, why not take a giant leap towards world harmony and safety and move the US to the European wire colour standard just as the UK has done? Don't bother answering, its sort of a rhetorical question.
                        Proabably for the same reasons that we don't move toward the metric system, old dogs refuseing to learn new tricks.

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                        • #13
                          Re: wire colors?

                          I believe Jeff Piette has answered this rhetorical question back on the first page of this thread. And I agree with him. Need to keep them separate.
                          Jim Don

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                          • #14
                            Re: wire colors?

                            Trying to get every major country to agree on any international standard for about anything truly takes an act of God and especially if this means having to make changes from how something has been done for many years.

                            I do feel that anything made for a given use area should be required to meet their code standards or that it should not be allowed to be sold in that area.

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                            • #15
                              Re: wire colors?

                              If you don't travel that often... it would not pose any problem...



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