Interesting three way conversion to two way and swap for time lag.

[The Ghost]

If your bored or like a challenge I thought (maybe wrongly) this might be interesting to trainees and maybe others. As the title convert three way switching to two way (Sw 2 + 3)

danlers time lag (Master and slave) using switch 2 and 3. Assume you cannot find the junction box. Can it be done? Note we have L in at switch 1, no accessible switch return. I included a couple of photos to give the ---- drawing some context. The switch return (green) is pure conjecture on my part, but it must be something along those lines. There is no switch return wire at any switch.

 

[The Ghost]

Oh sorry the first picture was meant to be intermediate switch like this:

 

[buzzlightyear]

the plan you are using will not work ,

 

[The Ghost]

will not work

You've given the game away. This is the existing wiring not the plan. The plan is what to do with it to get to Master and Slave on 1 and 2. I will tell you what I actually did before too long.

 

[buzzlightyear]

was that how it was wired ? and if saw you have two opposing current .switch 3 to switch 1.!

 

[telectrix]

question is... do to need to run the cable in mid-air over the neighbour's garden? if so to need a catenary wire as well as them strappers.

 

[Leesparkykent]

Looks like a standard 2-way to me. Feed in and feed out in the common of Sw1, strappers through intermediate switch and yellow from Sw3 is the SL to the light. If your getting rid of Sw1 you could connect the live through to sw2 and connect the SL and L through in parallel to switch 3. Or am I missing something?

 

[The Ghost]

Sorry did not label it but from the photos and diagram you should see the live comes into sw 1 common-to either L1 or L2 on red cables to the intermediate L1 and L2 (Sw 2) correspondingly (all belled out by the way) then from the intermediate top, to the three core R-Y-B two way switch (Sw 3) again belled out from intermediate L1 L2 top to L1 L2 on sw 3 hope that's clear. There is no switch return that I can make out. Or am I missing something?

 

[The Ghost]

Bear in mind the junction box is assumed as there is no other way the lights can switch on which they do by the way. I have had no sight of the junction box, could be in the wall joined to old MICC (quite common in this building) or JB in loft 20 foot up with a 2 foot by 2 foot hatch leading to a sargasso sea of cables dust an inch thick and billions of data cables just thrown over the loft and so on.

 

[Flanders]

Where is the light in your drawing , is the yellow cable the switch wire to the light via your hidden junction box?

 

[The Ghost]

was that how it was wired

The JB is just conjecture I could not bell out those wires conclusively. So no not necessarily.

 

[Leesparkykent]

Where is the light in your drawing , is the yellow cable the switch wire to the light via your hidden junction box?

That was my assumption.

 

[The Ghost]

Where is the light in your drawing

There are two lights on the stairs. If the yellow cable is the switch return where does the common go to at switch 1 if not the yellow cable at switch 3?

 

[Leesparkykent]

There are two lights on the stairs. If the yellow cable is the switch return where does the common go to at switch 1 if not the yellow cable at switch 3?

sw 1 common perm live, strippers through to int, other side of int to junction box, strappers connected to sw3 and Yellow from common sw 3 is SL to lights.

 

[The Ghost]

Feed in and feed out in the common

Eh? of switch 1 there is only 1 L feed into sw 1 there is no feed out and the rest of the cables look like an ordinary three way switching arrangement apart from on thing, there is no visible sw. return.

 

[Leesparkykent]

sw 1 common perm live, strippers through to int, other side of int to junction box, strapped connected to sw3 and Yellow from common sw 3 is SL to lights.

 

[The Ghost]

Yellow from common sw 3 is SL to lights.

Agreed, now you can't (for the sake of argument and practicalities) get to the junction box. So I want to convert this to two way master and slave time lag switch. So usually L and Sw return to master and use two of the strappers for the slave. But the L is at switch one which is being gotten rid of. The answer is a nothing to do with this problem I might add. It is just a mind bender for trainees really, and hopefully they might think it can't be done will have to do something else which I did.

 

[The Ghost]

@Leesparkykent you are missing the two wires in sw 1, look at the grid switch with a borrowed live from the adjacent grid switch you can see two wires in the common.

 

[buzzlightyear]

what a head scratcher, now let me think about it ,not the wiser .

 

[Leesparkykent]

Eh? of switch 1 there is only 1 L feed into sw 1 there is no feed out and the rest of the cables look like an ordinary three way switching arrangement apart from on thing, there is no visible sw. return.

looks like two reds in common to me.

 

[buzzlightyear]

I think I have got it .its gone now.

 

[The Ghost]

Where is the light in your drawing

Just assume there is a light and the L and N go to it. Just concerned with the three way lighting and how it pops the sw. return out.

 

[Leesparkykent]

@Leesparkykent you are missing the two wires in sw 1, look at the grid switch with a borrowed live from the adjacent grid switch you can see two wires in the common.

Yeah I see that, that's where it's picking its feed up from.

 

[The Ghost]

looks like two reds in common to me

Yep that's what I said, so one is the L what do you think the other one is?

 

[The Ghost]

So any trainees out there care to chime in?

 

[buzzlightyear]

So any trainees out there care to chime in?

you could do with a old timer on this one .

 

[The Ghost]

you could do with a old timer

Nah the problem is sorted just thought I'd throw it out there for a bit of light entertainment. Lets just say it's thinking outside the box, or cutting the gordian knot. I just thought it might be good for trainees to have a think about as it's the sort of thing we come across all the time and have to think it through.

 

[buzzlightyear]

Nah the problem is sorted just thought I'd throw it out there for a bit of light entertainment. Lets just say it's thinking outside the box, or cutting the gordian knot.

and I just put the pop corn in the mic/wave .

 

[The Ghost]

I assume it is something like this.

 

[Leesparkykent]

View attachment 42377 I assume it is something like this.

That would of never worked.

 

[buzzlightyear]

I assume it is something like this.

That would of never worked

try again ,Vort.

 

[The Ghost]

Well maybe not.

Ok if I go with the idea the yellow is the sw. return which was my first thought. Where does the mystery wire go? Maybe it is another feed to another light. But anyway the thing is, is it possible to do away with the first switch and run a master/slave time lag. And by the way at the light fitting it is a red cable as the sw. return. I know this is all a bit silly as I said just a bit of fun.

 

[buzzlightyear]

keep trying ,Vort ,it will come to you ,god loves a trier .

 

[AJshep]

It's late and I've had a few birthday beers tonight, but my thoughts are to run 2 masters rather than master and a slave.

Doesn't look like you have enough wires otherwise.

Does the live out (red) go to an Em light ?

 

[The Ghost]

Does the live out (red) go to an Em light

Sw 1 picks up its L from the adjacent grid switch, which is a fish key switch for the emergency lights with a separate supply to the emergency lights on the same circuit. If you switch off the fish key switch emergencies and lights on stairs go out together. Any yes it is a bit late to think this through.

 

[The Ghost]

2 masters rather than master and a slave

In order to run anything you would have to have a live and switch return. If I do away with sw. 1 there will be no live at sw. 2 and sw. 3. Anyway I had hoped some trainees would seize on this and lead the way. Shame they have not. I really don't want to make everything too obvious.

 

[The Ghost]

keep trying

Bit of input here @buzzlightyear would be appreciated. Give it to me baby.

 

[Wilko]

I've only got one thing to say ... no, not even one ...

 

[The Ghost]

Anyway I'm done for today can't even spell correctly. Or think, time for a steel bottom I'd say.

 

[The Ghost]

Anyway the two way switching is not the issue and is a complete red herring which I did not want to say but there I've blurted it out now as I'm getting tired. First off the whole of the two way switching would be disposed of. For a master and slave or master and master you only need two cables. Just a clue to the clueless.