Wall light 3 core cable with no earth

[SUNRAY]

It is not that long ago that 5 core flex sold here (probably with the European market in mind though) had Brown, Blue, G/Y for E, and two blacks originally for phase 2 and phase 3 in some countries.

So if used like that rather than the two blacks being for control purposes for stats or overrun etc then I was always conscious of European 3 phase conductors having say 415/400V between them. I thought our (at that time) Red/Yellow/Blue for phases to be more idea lor even B rown Black Grey although I have never liked Brown Black Grey so give me RYB or even the older R W B anyday.

And of course red, yellow and blue are primary colours and black is lack of any colour/lack of any voltage so very logical.

However the subject of core colours has been done to death a few times. example: https://www.diynot.com/diy/threads/brown-blue-black-and-g-y-flex.528547/

 

[ebee]

And of course red, yellow and blue are primary colours and black is lack of any colour/lack of any voltage so very logical.

Well said that man!
Agreed yes three of the six common used primary colours, to me they stand out pretty well ands that`s why I like `em.
The "New" Killer colours I do not like, I think wishy washy and do not stand out.
Folks I`ve asked (including colour blind and not colour blind) seem to feel the same in my opinion, others may disagree and I`d like to hear from those in order to get the full picture.
Anyway, those in charge decided, understandably it was done not unduly favour any one country or group but it seems that without that consideration then quite a few countries feel that ours was among the best (Now they tell us!)

 

[FrodoOne]

black is lack of any colour/lack of any voltage so very logical.

However, in North America, "Black" is the Line Wire (120 V) insulation (Red is the "other" 120 V "Line" Wire insulation, when 240V is used.)
and
"White" is the Neutral insulation- unless also "sleeved" with "Black", to indicate a "Switched Line".

And of course red, yellow and blue are primary colours

But, NOT the "Three Primary Colours".

The Three Subtractive Primary Colours" are Yellow, Magenta and Cyan and,
together with Black (designated by "K")
are used in "Four Colour Printing"
(See https://en.wikipedia.org/wiki/CMYK_color_model
If you change the order to YMCK, it may be easier to sing !)

(Your Primary School teacher was wrong when they told you that the Three Primary Colours are Red , Yellow and Blue..)

The "Three Additive Primary Colours" are Red, Green and Blue - as used on the screen which you are now viewing.

(See https://en.wikipedia.org/wiki/Primary_color
https://science.howstuffworks.com/primary-colors.htm )

 

[ebee]

Correct, that is the normal set of 2 off 3 primary colours.
However there are other, far less common, combinations that may be used as primary colours too.
Therefore our beloved "old colours" are made with 2 primary colours from one set and 1 of the other set.

PS - at school for art, which were you taught as the three primary colours for paints? Was it actually correct?

 

[RandomGrinch]

When I removed the two light fittings I found each one is supplied by a 3 core cable with the following wires. One red, one black and one black with a red sleeve.

Two pages now, and what no-one yet has seemed to have asked...

Assuming the wall lights worked (probable, given there is no pendant in the room), how were the existing wall lights connected up - was it to the black and 'black' oversleeved in red?

And given...

All wiring is buried in the wall in metal conduits.

Were the old light fittings attached to a metal back box connected to this conduit?

As suggested here...

I think you'd best post a picture

 

[robinbanks]

PS - at school for art, which were you taught as the three primary colours for paints?

For most people this is RYB alas

Was it actually correct?

It depends. Correct as in "a result a 5 year old would be happy with" or as in "a result a lithographer would be happy with" ?

 

[RandomGrinch]

It depends. Correct as in "a result a 5 year old would be happy with"

And physicists are usually happy enough using RGB additive models for Grassmann's law, etc.

Also, has anyone wondered if brown is actually a colour at all, when in RGB, it is just a dark orange?

 

[Adam_151]

Also, has anyone wondered if brown is actually a colour at all, when in RGB, it is just a dark orange?

Nah, too busy thinking wondering about CFL lamps, vintage photography processes and the amount of relay logic that old jukeboxes and pinball machines had....

 

[ebee]

Aye, quite a lot of control logic got done by relays years ago

 

[SUNRAY]

Aye, quite a lot of control logic got done by relays years ago

and a fair bit of new still does.

 

[Harry Bloomfield]

The "New" Killer colours I do not like, I think wishy washy and do not stand out.
Folks I`ve asked (including colour blind and not colour blind) seem to feel the same in my opinion, others may disagree and I`d like to hear from those in order to get the full picture.

I never agreed with the confusing new colours, either.

 

[FrodoOne]

Aye, quite a lot of control logic got done by relays years ago

Like in Telephone Exchanges !

See http://www.coxhill.com/trlhistory/m...ublications/Telephony 3. (reissued). 1951.pdf
starting at about Page 69 in this document.

While the equipment described in this Australian document is (US) "Strowger", BPO (British Post Office) equipment (also used in Australia) has many "similarities", plus improvements.

 

[Jurassicspark]

Wow, this thread is really informative for the OP.

 

[SUNRAY]

Wow, this thread is really informative for the OP.

Yep absolutely, but the way I see it; we can only kick a can around until OP comes back with useful information.

 

[Ragnar_AT]

Wire colours are arbitrary decisions without any absolute rationale behind them. The only rational arguments are to use a colour combination for earth that can be recognised even by people with any known type of colour blindness and not to use colours that can be confused easily in poor lighting conditions for very different purposes (e.g. L and N).

The current UK colours are the result of over five decades of international negotiation and used throughout Europe as well as in a number of countries outside Europe but there's nothing inherently good or bad about them other than what I mentioned above.