In message , Mike Tomlinson
writes:
In article ,
Terry Casey writes

Finally, the sleeving was changed from green to green/yellow ..

IIRC, it was to make it easier for colour-blind people to identify.

Yes - green/red being the commonest form of colourblindness. Though
making one stripy meant anyone could get it. (A physics master - I think
it was - once told me: brown is what you'll go if you touch it, green
and yellow think buttercups on grass i. e. earth.)

Old German (flex - I don't know about house) colours were red, black,
and grey - I can't remember which was which. I have an old globe with
these colours.

There's also been another change: the cores in T&E (=romex) used to be
red and black for phase and neutral, now it's been harmonised with
Europe to brown and blue.

Three-phase wiring has been harmonised from red, blue and yellow for the

Or, a _long_ time ago, red, blue, and white. (I did my apprenticeship
with Reyrolle Switchgear, where Really old came up all the time ...)

phases and black neutral to brown, black, black and blue neutral. Yeah,
I know...

It _does_ seem odd. Not only the change keeping black but for a
different purpose, but also having _two_ of the phases the same colour.
(If that _is_ truly the case and not one of them grey, as some have
claimed in this thread.)

Though on the subject of motors turning the wrong way etc.: is it
definitely true that you always get the same phase relationship between
red, blue, and yellow? (And what happens at star-delta or delta-star
transformers: are the outputs still coloured red, blue, and yellow?)
--
J. P. Gilliver. UMRA: 1960/1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf

The love that dared not speak its name, has become the love that won't shut
up. - Simon Fanshawe (article on Gay Comedy), Radio Times 25 Sept-1 Oct 2010