I think i've flipped up
I was under the impression we use the Brown Blue and Green/Yellow help with colour blindness (most common green and red)
I know it's to bring UK in line with EU. But why did EU use them colours.
Because I understand green earth (CPC)
Red Live (line) [hot colour]
(Forgive any misspellings Dyslexic and hard to see , also miss out works as forget to type them)
The electrons do not care - but we do as it makes it easier to remember what is going on. (*)
Well, colours have changed many times in the past, and may well do so again. In the UK green was earth after the war (earth was black pre-war, if it was there at all, and green was 3rd phase, so live in some installations of that era) and earth became stripy in 1970 - and this was coordinated across the EC as it was then - previous there were many national standards - as an example of the problem, in Germany black was a live colour, and red was reserved for earth, as earth is a really important safety thing, to them making it red seemed like a good idea.
Actually Red for earth was also used in Switzerland and parts of the soviet block as well.
But stripy looked like nothing else and was accepted almost immediately. There is also an advantage for colour-blindness, that the stripes of something light and something dark are still unique.
The UK 'red for live' and the German red for earth meant that sensibly red had to go. So brown - a bit like the German black, and a bit like the English red, but not easily confused with either became the new live on single phase flexibles.
However, in the UK fixed wiring stayed with red and black until 2004 - arguably as it does not get moved around like portable gear and is unlikely to be opened by someone unfamiliar with local regs it was not seen as a priority.
Now (post 2004) we have got used to the flex colours and the fixed cable colours being the same
Live 1 brown
Live2 Black
Live 3 light grey
Neutral blue
stripy green yellow earth.
Mike,
* well not always. sometimes you find things like 3 phases, with a live on brown, a live on blue and a live on green yellow. At this point a multi meter and some nerve is needed to sort out what is happening.
And our idea of standard colours is by no means universally accepted - look at the pics in this thread to worry yourself about practices in Baku, Azerbaijan here
Later edit actually the pics have not survived the forum re-shuffle , so here is one. Note the use of green and yellow for a 3 phase supply, as well as for earth/neutral , and blue for the meter wires as well... oh and the open live terminals at the bottom.
The electrons do not care - but we do as it makes it easier to remember what is going on. (*)
Well, colours have changed many times in the past, and may well do so again. In the UK green was earth after the war (earth was black pre-war, if it was there at all, and green was 3rd phase, so live in some installations of that era) and earth became stripy in 1970 - and this was coordinated across the EC as it was then - previous there were many national standards - as an example of the problem, in Germany black was a live colour, and red was reserved for earth, as earth is a really important safety thing, to them making it red seemed like a good idea.
Actually Red for earth was also used in Switzerland and parts of the soviet block as well.
But stripy looked like nothing else and was accepted almost immediately. There is also an advantage for colour-blindness, that the stripes of something light and something dark are still unique.
The UK 'red for live' and the German red for earth meant that sensibly red had to go. So brown - a bit like the German black, and a bit like the English red, but not easily confused with either became the new live on single phase flexibles.
However, in the UK fixed wiring stayed with red and black until 2004 - arguably as it does not get moved around like portable gear and is unlikely to be opened by someone unfamiliar with local regs it was not seen as a priority.
Now (post 2004) we have got used to the flex colours and the fixed cable colours being the same
Live 1 brown
Live2 Black
Live 3 light grey
Neutral blue
stripy green yellow earth.
Mike,
* well not always. sometimes you find things like 3 phases, with a live on brown, a live on blue and a live on green yellow. At this point a multi meter and some nerve is needed to sort out what is happening.
And our idea of standard colours is by no means universally accepted - look at the pics in this thread to worry yourself about practices in Baku, Azerbaijan here
Later edit actually the pics have not survived the forum re-shuffle , so here is one. Note the use of green and yellow for a 3 phase supply, as well as for earth/neutral , and blue for the meter wires as well... oh and the open live terminals at the bottom.
