Two 2way light circuits.

[TonyW2]

I have two separate one way switched lights in a large garage, with switches on opposite walls and intend to convert each to 2way operation for convenience, BUT maintain the separate illuminated areas.
I will need to replace the single way one gang switches with two gang 2way and could use two runs of 3core and earth between the switches as a conventional method.
I believe I could instead use three runs of 2core & earth if I used the brown and blue wires of one of the cable runs for the two separate commons.
Is this acceptable practice? If so what sleeve colours should I use on the interconnecting wires ends?
My only reason for considering this way is just that I have plenty of the 2+ cable and no 3+.
Any comments, please?

 

[ban-all-sheds]

They should all be sleeved brown.

And I strongly advise some letter or number identifiers as well to tell them all apart.

Or, if the rest of the light wiring is easy to get at:

 

[TonyW2]

Thanks for the quick reply. Brown it will be and the identifiers are a wise idea.
Would that circuit diagram, though, be only economically suitable for an "industrial" single wire cable set-up?

 

[sparkwright]

I would say chances are you won't follow the diagram, although the diagram does indicate good use of using 2 core+e, which is why it was posted I suppose.

Possibly more rewiring would be required to obtain something along these lines.

Alternatively stick to the more usual 'modern' methods, though substituting 2 core for 3 core.

Are the lights on the same circuit? If for some reason they aren't, be sure not to mix two circuits within one of your new cables - I'm guessing you would want to run three 2 core+e cables between the switches.

 

[TonyW2]

It's all one circuit, o no chance of borrowed neutrals, thanks. Yes, it would be 3 cables of 2+e and I am OK with the layout, so long as it is an acceptable method.
You are correct, that i have not really understood BAS's diagram, if it is useful for 2+e, so I will study it further as a learning exercise. (I can't get its application to 2+e when the lights are far apart)

 

[EFLImpudence]

How is it wired at the moment?

Does the supply cable go to the switches and then a cable up to the lights or

does the supply cable go to the lights with a cable down to the switches?

 

[sparkwright]

When I said the chances were that you wouldn't follow Ban's diagram, I meant you may not choose to USE it. I didn't mean you wouldn't understand it.

There are other diagrams out there that may suit your wiring better, and therefore give you minimal work. I think all you need is to run three 2 core+e cables between the switches, but as i don't know how your garage is wired there may be options.

 

[ban-all-sheds]

My only reason for considering this way is just that I have plenty of the 2+ cable and no 3+.
Any comments, please?

I'm minded to comment:

"Well, yes, but, for the sake of a few quids worth of 3C&E....."

 

[kentishman]

I'm not a spark, and I stumbled here as I have a similar situation, but... would it be possible to wire it with just two 2C&E between the two switch positions? I'm thinking as switch position "A" already has a line and a switched line (for lamp "A"), and switch position "B" has a line and switched line (for lamp "B"); then could you use the line at switch "A", via a 2W switch and strappers to a 2W switch at "B" to switch lamp "B", and vice-verca?
A rough sketch...

 

[securespark]

As long as the line conductors originate from the same CPD.

 

[EFLImpudence]

Yes, well done Kentishman.

I was just drawing a diagram for looped at rose wiring - the same as yours.
Similar for looped at switch.

 

[sparkwright]

Good drawing, that would make good use of the 2 core+e, and clear diagram for the op, and minimal disruption.

 

[333rocky333]

Would there be any problem though, of an induced voltage at the second set of lights when the first set are on

 

[sparkwright]

I can't help thinking getting some 3 core+e and doing this is the standard conventional manner would be the best method.

 

[bernardgreen]

Very good design by Kentishman, Well done.