Feed and switch wire at an intermediate...

[TJC1]

Evening all

Try to rack my brain about whether this would work.....

Customer on a job wants to add a 3rd switch on a lighting circuit, however it is near impossible to get from the 2way switch but easy to get from the first switch

Will having the intermediate switch where the feed and switch wire work.....

Cheers

T

 

[goasis]

Yup,So instead of joining the 3rd cores together at the inter, feed in joined to go to common one of the 2 way switches, light feed joined to go off to common on the other 2 way, strappers as per usual on the inter.

 

[TJC1]

Amazing! Cant quite follow that but Im sure I can make it work ?

 

[goasis]

Ha! Someone may explain it better or if you're lucky, draw a pretty picture!

So using your colours of choice:

L1 brown, l2 grey black common at the 2 ways

At the intermediate: brown and greys into L1 and L2 as normal.
Join one black to permanent live in
Join others black to switched live to light

 

[littlespark]

Or join the 2 blacks… live onto L1 with the brown, switchwire off L2 with the greys.

 

[timhoward]

Don't know if this helps. Orange is a switch.
Middle one is intermediate, either as shown, or crossed over.

 

[timhoward]

I suppose the easiest way of thinking about it is to take the normal basic 2 way switch setup with 2 strappers between L1 to L1 and L2 to L2. Then the feed to the common on one switch, and the load from the common on the other switch.
All you are doing is extending each common to the middle using the 3rd core.

The intermediate switch is just swapping the two strappers over and could be at any point on the circuit, or not be there at all.

 

[Lucien Nunes]

To sum up:
Either of the two normal configurations will work just fine.
@timhoward shows the 'conventional' option above.
@littlespark describes the 'conversion' option. In this case, where all three terminals of both 2-ways are connected together with L & SL paralleled to L1 and L2, it doesn't matter where in the run of strappers they tap in provided they are both on the same side of the intermediate switch.

 

[theshaniqua]

The intermediate switch is just swapping the two strappers over and could be at any point on the circuit, or not be there at all.

So it is possible to have this 3 way set up without an intermediate?

 

[loz2754]

So it is possible to have this 3 way set up without an intermediate?

No

 

[timhoward]

So it is possible to have this 3 way set up without an intermediate?

If you want 3 or more switches the ones in the middle need to be intermediates.
The switch wire can be at any of them.

A completely alternative strategy is to look at Quinetics wireless switches.

 

[theshaniqua]

Had to read this thread a few times, but I think I got it.

So my understanding is that these are the two options described above - please correct me if I am wrong (and forgive my crude PowerPoint drawings)

and

 

[telectrix]

option 2 is wrong. the black should link the 2 commons of Sw! and SW2 but go straight through intermediate with no connections to the switch itself.

 

[cliffed]

option 2 is wrong. the black should link the 2 commons of Sw! and SW2 but go straight through intermediate with no connections to the switch itself.

Option 2 would still work I do believe ?

 

[littlespark]

Option 2 would still work I do believe ?

No, it wouldn’t. Draw in the lines, and you’ll see. Changing any switch has no effect as the same cables are paralleled at another switch.

The black in the commons just gets linked through the intermediate.

 

[timhoward]

@theshaniqua crude edit....

 

[theshaniqua]

That's very helpful, thank you all for your patience!

 

[Lucien Nunes]

It's still wrong. PL and SL must tap into the brown and grey of the same strapper cable. Imagine they were paralelled at one of the 2-ways, and then just transferred to the other end of the same strapper cable.

 

[theshaniqua]

@Lucien Nunes like this?

 

[Lucien Nunes]

Yes. I think manufacturers are inconsistent with labelleling L1 and L2 on intermediates. Traditionally I recall it being L1 for both 'brown' terminals and L2 for both 'grey', but have seen drawings as per yours with L1 for both terminals facing one 2-way and L2 for both facing the other. Perhaps someone could confirm? I don't usually install light switches so it's ages sinnce I looked at one.

 

[telectrix]

perm L into L1, SWL into L2. no use putting both in L1.

 

[goasis]

Yes. I think manufacturers are inconsistent with labelleling L1 and L2 on intermediates. Traditionally I recall it being L1 for both 'brown' terminals and L2 for both 'grey', but have seen drawings as per yours with L1 for both terminals facing one 2-way and L2 for both facing the other. Perhaps someone could confirm? I don't usually install light switches so it's ages sinnce I looked at one.

You're right, they do vary from manufacturer

 

[Avo Mk8]

You're right, they do vary from manufacturer

They certainly do. More or less any combination you like ?
The common theme seems to be a terminal at the top gets connected to one or other at the bottom ?
(as you might imagine from the construction of the thing). Amongst others Schneider go for L1, L2, L3, L4

 

[timhoward]

It's still wrong. PL and SL must tap into the brown and grey of the same strapper cable. Imagine they were paralelled at one of the 2-ways, and then just transferred to the other end of the same strapper cable.

My bad I didn't notice that

 

[johntheo]

Is this correct?.

 

[cliffed]

No, it wouldn’t. Draw in the lines, and you’ll see. Changing any switch has no effect as the same cables are paralleled at another switch.

The black in the commons just gets linked through the intermediate.

Missed that well spotted ?