Neutral is a live conductor...
Replacing light - House that jack built!
- Thread starter AnnaA1982
- Start date
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Sorry, line. 
Suppose an unharmonised 3 core+E has to get jointed to a harmonised 3 core+E.
For arguments sake let's say the joint is inaccessible.
Now obviously there may or even may not be coloured sleeving used, but for fault finding and future alterations, wouldn't it be so much easier if the wires were joined in the accepted
red-brown
yellow-black
blue-grey
?
These 'phase' colours are always arranged in this sequence; look at the structure of a 3 core+E cable. Or the layout of a three phase board.
It always goes red, yellow, blue. Or brown, black, grey.
So connecting a junction box with the yellow and blue crossed over with the black and grey doesn't seem electrically right.
For arguments sake let's say the joint is inaccessible.
Now obviously there may or even may not be coloured sleeving used, but for fault finding and future alterations, wouldn't it be so much easier if the wires were joined in the accepted
red-brown
yellow-black
blue-grey
?
These 'phase' colours are always arranged in this sequence; look at the structure of a 3 core+E cable. Or the layout of a three phase board.
It always goes red, yellow, blue. Or brown, black, grey.
So connecting a junction box with the yellow and blue crossed over with the black and grey doesn't seem electrically right.
Yes, that would definitely be sensible in three-phase and probably in single-phase too but if the joint is inaccessible you will still be unsure and have to test.
Also, in single-phase, because of the silly colours used (BBG) and when one of them is neutral you will never be sure unless sleeved blue, will you?
I think this all started because I wrote that when connecting harmonised 3C+E to non-harmonised 2C+E for PL,SL,&N in a fan (or strappers in two-way lighting) I would connect black to black.
I think that is sensible.
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And when you were presented with a red/yellow/blue cable, how could you be sure that blue was neutral unless sleeved black?
On occasion, at a 2 way switch with a red and black switch cable and a harmonised 3 core+E 2 way cable, I HAVE connected the two black wires together - simply because I thought it looked neater.
However, that was years ago.
Because, with the old colours, I always tended to connect the red switch wire to a yellow strapper; and the black switch wire to a blue strapper,
I usually
connect the brown switch wire to a black strapper; and the blue switch wire to grey strapper.
So with that in mind, the situation at the top of this post wouldn't have the two blacks together.
Anyhow, I'm certainly not going to object how 2-way switches are connected.
The individual will have his own quirks on this, and there's always been many variations to choose from.
One thing springs to mind is what colour to use as 'common'. It was usually red, if not, yellow. Rarely blue, for some reason. Not that I feel this is particularly important.
However, that was years ago.
Because, with the old colours, I always tended to connect the red switch wire to a yellow strapper; and the black switch wire to a blue strapper,
I usually
connect the brown switch wire to a black strapper; and the blue switch wire to grey strapper.
So with that in mind, the situation at the top of this post wouldn't have the two blacks together.
Anyhow, I'm certainly not going to object how 2-way switches are connected.
The individual will have his own quirks on this, and there's always been many variations to choose from.
One thing springs to mind is what colour to use as 'common'. It was usually red, if not, yellow. Rarely blue, for some reason. Not that I feel this is particularly important.
That is a possibility but, as above, it was never seen that a yellow would have been used for neutral.
I don't think that alters anything I have written.
Using the modern 2 way switching and old colours I quite like using blue as the common these days. This leaves the red as permeant live
And yellow as switch live, which us all very sensible and therefore you know the wire functions at the remote switch.
And yellow as switch live, which us all very sensible and therefore you know the wire functions at the remote switch.
As you say - quirks - but I would always use the red for the permanent live strapper.
Yes, I think red is logical to be the perm live strapper.
However, I use red as the common, only because that's how I was taught, and how I've always done it.
Red in com was certainly the way I was taught.
Maybe not, but does it call into question how sure you should be?
Even if you have never seen a 3C+E cable where the blue was not used for the neutral, would you trust your life to the assumption that it was?
I think if you saw a yellow in a switch terminal you would assume it was live line.
If you saw a blue going into a block with a load of blacks you would assume it was neutral.
If you saw a blue going into a block with a load of blacks you would assume it was neutral.
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