2/3 way switching to follow

[SUNRAY]

Today I've been assisting a colleague over the phone, he is Polish, so a very minor language barrier, and HV registered in UK. I first met him while installing an 11KV sub and main switchgear panel etc in a brand new factory building.

He's stuck on a '3 way lighting system' and to complicate it I was getting a description of '3 3 ways with 8 wires'. He started discussing colours and got the list of 'weird' combinations totalling: Red=6, Black=5, Blue=3, Grey=1, Brown=3, yellow=5, Green=4, total=27. Then he started talking about 'California method' (which I've heard of but no experience or knowledge of) and 'Chicago method'.

The description was all over the place and I can't get to the bottom of it. We've given up for now, I'm meeting him there on BH Monday.

In the meantime I've searched on here and found only these 2 threads;

https://www.diynot.com/diy/threads/is-this-3way-switching-without-an-intermediate.408036/

https://www.diynot.com/diy/threads/lights-will-not-switch-off.18413/page-5#post-110479

Which seems to go with the system where L & N are connected to L1 & L2 of the 2 way switches and the lamp is connected between the com's

Google comes up with a fair bit but Chicago and California, both appear to be the same as our 'Conversion method' a YT describes 'California method' quite well but comes up with the point it cannot include an intermediate:

My initial thought was 'rubbish' but then I realised that pretty much all of the American descriptions show the line feed at one switch and the SL taken from the other, in which case an intermediate cannot be used. Also this sreen shot mentions 3 & 4 way switches as opposed to 2 way and intermediate. I'm really wondering what I'll be looking at now.

 

[bernardgreen]

'Chicago method'.

'California method'

Have a gamble and use the Las Vegas method

 

[JohnW2]

My initial thought was 'rubbish' but then I realised that pretty much all of the American descriptions show the line feed at one switch and the SL taken from the other, in which case an intermediate cannot be used.

Why not? ...

KInd REgards, John

 

[333rocky333]

My initial thought was 'rubbish' but then I realised that pretty much all of the American descriptions show the line feed at one switch and the SL taken from the other, in which case an intermediate cannot be used.

The line feed is at both switches though.
The reason you cannot fit an intermediate is once operated you would need to operate both other switches to turn the light off

Also this screen shot mentions 3 & 4 way switches as opposed to 2 way and intermediate.

Is that not reffering to the amount of switch terminals

 

[sparkwright]

Today I've been assisting a colleague over the phone, he is Polish, so a very minor language barrier, and HV registered in UK. I first met him while installing an 11KV sub and main switchgear panel etc in a brand new factory building.

He's stuck on a '3 way lighting system' and to complicate it I was getting a description of '3 3 ways with 8 wires'. He started discussing colours and got the list of 'weird' combinations totalling: Red=6, Black=5, Blue=3, Grey=1, Brown=3, yellow=5, Green=4, total=27. Then he started talking about 'California method' (which I've heard of but no experience or knowledge of) and 'Chicago method'.

The description was all over the place and I can't get to the bottom of it. We've given up for now, I'm meeting him there on BH Monday.

In the meantime I've searched on here and found only these 2 threads;

https://www.diynot.com/diy/threads/is-this-3way-switching-without-an-intermediate.408036/

https://www.diynot.com/diy/threads/lights-will-not-switch-off.18413/page-5#post-110479

Which seems to go with the system where L & N are connected to L1 & L2 of the 2 way switches and the lamp is connected between the com's

Google comes up with a fair bit but Chicago and California, both appear to be the same as our 'Conversion method' a YT describes 'California method' quite well but comes up with the point it cannot include an intermediate:
View attachment 232099
My initial thought was 'rubbish' but then I realised that pretty much all of the American descriptions show the line feed at one switch and the SL taken from the other, in which case an intermediate cannot be used. Also this sreen shot mentions 3 & 4 way switches as opposed to 2 way and intermediate. I'm really wondering what I'll be looking at now.

I'm struggling with the drawing with the two switches.
I have drawn it out and can't get the 2 way switches to work properly.
Which terminals are supposed to be the commons??

 

[EFLImpudence]

Why not? ...

I did think they do it like that for EMF reasons but that wouldn't work in some configurations, would it?

 

[EFLImpudence]

Which terminals are supposed to be the commons??

The middle ones.

 

[sparkwright]

Ok. Let me have another go...

 

[EFLImpudence]

It would have been easier to see if they had done this:

 

[JohnW2]

I did think they do it like that for EMF reasons but that wouldn't work in some configurations, would it?

There certainly were (and in some cases still are) such potential EMF issues' in some of the 2-way and 3-way switching in my house. However, such issues can be avoided if one runs the N through all of the switches, using 3C+E cables between them.

In any event, SUNRAY seemed to be saying that if L was fed to one switch and S/L taken from the other, then it would be impossible (which I tool to mean 'literally impossible') to use an intermediate switch - and, as my diagram illustrated, that is not true.

Kind Regards, John

 

[sparkwright]

Crazy way of doing it, think I have seen this once on a 70s 2 way conduit system, which I found confusing at first.

I suppose in some cases this way could be advantageous if you are trying to adapt some existing wiring, don't think I'll be bothering doing it this way if I can help it.

 

[JohnW2]

I'm struggling with the drawing with the two switches. I have drawn it out and can't get the 2 way switches to work properly. Which terminals are supposed to be the commons??

It also took me a bit of thinking but I eventually saw that it would work. As EFLI has said, the 'commons' of the switches are the ones nearest to the middle of the diagram.

Kind Regards, John

 

[EFLImpudence]

Yes, I can't see any configuration being better for EMF, so I can't see any point wiring it like that.

 

[JohnW2]

Crazy way of doing it, think I have seen this once on a 70s 2 way conduit system, which I found confusing at first.

As I've just written, so did I, initially! I certainly have not seen that done, but what I depicted in post #3 is the ('traditional'/'old-fashioned') way in which most of the 2-way and 3-way switching in my house has been done (other than bits I've added more recently).

Kind Regards, John

 

[sparkwright]

It would have been easier to see if they had done this:

View attachment 232116

Somehow that does actually help.