Why neutral at other switch?

:) ... I'll be on the lookout for your typos!!
hopefully only the nice ones!
What "it" are you talking about?
Kind Regards, John


I believe number 3 with L&N both appearing at both switches is still practiced in USA if one of the YT videos I saw a little while ago is valid.
It used to be popular for outside lighting between buildings, for example farms, where a light mid way between buildings only required one wire from each end.
 
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I believe number 3 with L&N both appearing at both switches is still practiced in USA if one of the YT videos I saw a little while ago is valid. .... It used to be popular for outside lighting between buildings, for example farms, where a light mid way between buildings only required one wire from each end.
That presumably can only work in the absence of RCDs - since, when there are RCDs, it's unlikely that the supplies in two different buildings would be protected by the same RCD - and it would be rather a self-defeating exercise to ran an L+N cable between buildings to achieve that?

Kind Regards, John
 
That presumably can only work in the absence of RCDs - since, when there are RCDs, it's unlikely that the supplies in two different buildings would be protected by the same RCD - and it would be rather a self-defeating exercise to ran an L+N cable between buildings to achieve that?

Kind Regards, John
Absolutely correct on all counts.
But think further and assume each building has an all points isolator and hence the system can apply power via a lamp bulb to an otherwise isolated building.
Then consider building on different phases, when switched off the light will either have 'N' both sides or 'L' both sides and if 'L' they will be ph to ph voltage or 400V.
 
Absolutely correct on all counts. But think further and assume each building has an all points isolator and hence the system can apply power via a lamp bulb to an otherwise isolated building.
If you're mentioning that as another reason why one should not use that switching method, then I agree ... and ...
Then consider building on different phases, when switched off the light will either have 'N' both sides or 'L' both sides and if 'L' they will be ph to ph voltage or 400V.
... I think we've already agreed that such is yet another potential problem/hazard of such a practice.

Kind Regards, John
 
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If you're mentioning that as another reason why one should not use that switching method, then I agree ... and ...
... I think we've already agreed that such is yet another potential problem/hazard of such a practice.

Kind Regards, John
If used within a relatively small installation without those highlighted points then it is a workable and fairly trouble free method.
The thread I linked to in post #28 had been in use for a while. I don't know if it had been there before the building extention but changing it was out of the question without a fair amount of work. However there was another light wired the same way in the house working trouble free for something like 20 years.

I am agreeing with you and wouldn't install this way, except to admit to doing it to get something working quickly after a problem and then only on a temporary basis.
 
If used within a relatively small installation without those highlighted points then it is a workable and fairly trouble free method.
I suppose one could debate "fairly trouble free" at length, but I would personally never do it.

Kind Regards, John
 
I can't understand this talk of three-core wired 2 way switches being branded "new".

Three core has been around decades.
The first time I remember coming across three core was in a 1950s built house. It was red, white and blue with no CPC.
 
I'm fairly certain it was available in rubber too, again no cpc. The cable I think I have seen was hard to identify core colours as insulation all dried up and crumbling. From memory, we worked out it was from 1952.
 
I can't understand this talk of three-core wired 2 way switches being branded "new". Three core has been around decades. The first time I remember coming across three core was in a 1950s built house. It was red, white and blue with no CPC.
I can't speak for others, but I have never intended to suggest that use of 3-core cable for 2-way switching is in any way 'new'. Several of the 2-way switching circuits I inherited some 35 years ago, and probably all of the 2-way switching I have ever installed, have used 3-core cable, but with the 'old'/'traditional' wiring method (i.e. the 3-core cable carrying the strappers plus a neutral).

In comparison with using 2-core cable for just the strappers, that is better EMC-wise and also considerably lessens the chance of 'a neutral being borrowed'.

Kind Regards, John
 
I can't understand this talk of three-core wired 2 way switches being branded "new".

Three core has been around decades.
The first time I remember coming across three core was in a 1950s built house. It was red, white and blue with no CPC.
I don't think anyone is saying 3C or 3C&E is new, indeed I remember helping my father wire up a 3ph fan on a pig farm. Well I say helping but at the time I was about 4 years old. However my experience (and it seems several others on here) is the so called 'Conversion method' was unheard of in the 50's and well into the 60's I think the first time I encountered I was driving - so well into 70's. The fact the method used then is now called 'conventional method' seems to back that up to some extent.

My mid 60's home still has a piece of R,W,B 3C 3/0.029":
full
Which if one looks is wired for 2 'Convential method' circuits but the routing of the cores is somewhat 'unconventional'. Initially I assumed this was not original but have found almost identical wiring in several neighbouring properties.

I'm still wanting to hear or read someones real time memory of installing 'Conversion method' in those early days
 
I'm still wanting to hear or read someones real time memory of installing 'Conversion method' in those early days
Same here. I wonder when it first started to be used (or, indeed, when it was 'first described' and started being taught and appearing in books)?

It's certainly only 'relatively recently' (probably no more than 20 years ago) that I personally even heard of it - and I recall that 'first time', when I had top do a fir bit of 'scribbling on a fag packet' to convince myself that it would/could actually work!

Kind Regards, John
 
I remember reading about it in a DIY book before I started first working with electrics.

That puts it circa 1982.

But that imperial 3 core with no CPC I found in that 1950s light switch was wired as the conversion method.
 
I remember reading about it in a DIY book before I started first working with electrics. That puts it circa 1982.
Interesting. I would have been reading such books from the early/mid 60s onwards but, as I said, it was probably nearer 2000 when I first became aware of the 'conversion method'.

Kind Regards, John
 
Sadly, I can't find the book.

I may have loaned it out and not got it back, otherwise I would post some pics.
 
Yes by 80's it was very common, I recall reading a letter in a 'Practical Householder' which I purchased occasionally (less than half a dozen total) after I started looking for my first house about 1978, the letter was about having to provide a connecter in the back box while changing a broken switch as there wasn't one and wot working properly after. The reply was probably the first time I'd seen 'conversion method' documented although I don't recall it having that name then, in fact I'll stick my neck out and say I don't remember the title being used until using this forum.
Annoyingly I cleared them out with a load of old Radcom, PE & PW magazines only about 5 years ago.

SS if you've been working in this environment since 80's there is a slim chance something from 50's may have been reconfigured in later works by someone who doesn't know/understand conventional.
 

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