2 way switch (3 wire system) four lights in parallel ?

[W.olly]

Hi all sparky fans, i am trying to get my ehad around this 2 way switch (3 wire system) but to wire in four lights in a 12v system and want it wiring in in parallel.
Any help with the way to wire it up or diagram please.

Using this diagram where would you fit the lights?

Cheers

wolly

 

[skotl]

Where the circle with the cross on it is. It has switched live on the right and neutral on the left.

(obviously, the actual load would be the transformer that then fed the 12V lamps - you can wire the 12V lamps in parallel with the DC out from the transformer)

 

[Seadog]

The circled cross is a lamp, just parallel another three across it.

 

[dobbslc]

If you can get away from using 12v lights and transformers I would. Are they down lighters?
They can be a PITA and produce quite a lot of heat.

 

[skotl]

If you can get away from using 12v lights and transformers I would. Are they down lighters?
They can be a PITA and produce quite a lot of heat.

Agreed, but if you really want to, here's the diagram

 

[W.olly]

Its a set of down lighters for a boat so direct from the consumer.

serious blonde moment i think, ill be back with a diagram of it, to tired i think, i am trying to keep the cable lengths the same

 

[W.olly]

this way, cracking diagram hey lol it is the way it will be set out on the boat.

 

[skotl]

this way, cracking diagram hey lol it is the way it will be set out on the boat.

View attachment 94739

Mmmm.... Are they now 240V lamps, not 12VDC ones?

If so then, you're on the right track but you seem to have connected up both contacts on the first switch to live, which will mean the lights stay permanently on.

Gimme a sec and I'll try another diagram. By the way, if it's 240VAC mains (or, in fact, any AC supply) then there's not really a "+" and a "-"; it's live and return (or neutral in old-fashioned speak).

 

[skotl]

Like this;

Specifically;

Incoming live goes to L1 on both of the 2-way switches.
Common on both switches are linked together.

L2 on both switches are also linked together - you can either do this at the switches or connect L2 on each switch directly to the first lamp. This (the combined L2) is the "Switched Live"

Connect all four lamps together on one side to the Switched Live.

Connect all four lamps together on the other side to return / neutral.

 

[Seadog]

You beat me to it Skotl

 

[skotl]

You beat me to it Skotl

Me and Microsoft Paint - a match made in heaven

 

[Johnseat]

Go on then @skotl how would you change the diagram to remove a switch and replace it with a pir.

 

[skotl]

Go on then @skotl how would you change the diagram to remove a switch and replace it with a pir.

Good question! Never done that, but I would expect the PIR would need a neutral.
Can you then do away with the 2-way switch on the left and just have a 1-way feed the switched live out of the PIR? Not sure how happy a PIR would be with have live introduced to its switched output?

I've resisted googling it, so the above is just off the top of my head

 

[wookie]

It's a boat with 12 volt electrics, that's not to say he doesn't have shore power/240Vac but generally lighting is done to run off the batteries.

 

[skotl]

Good question! Never done that, but I would expect the PIR would need a neutral.
Can you then do away with the 2-way switch on the left and just have a 1-way feed the switched live out of the PIR? Not sure how happy a PIR would be with have live introduced to its switched output?

I've resisted googling it, so the above is just off the top of my head

Edit: Just thought about this some more and PIRs generally feed a relay, don't they? So I'm going with my original answer; a 1-way switch supplying live in parallel with the PIR!

 

[wookie]

Having looked at your diagram Skoti, I usually wire 2 way switching like this, it doesn't matter as both ways work but for some reason in my head this just looks better.

 

[sparkysy]

Hi @W.olly
That diagram will not work as a 2way switch as in you will be able to turn all the lights on and off from one switch but not on at one switch and off at the other. I can't draw on my phone but usually you would run the live feed to 1 common on the 1st switch and the switch live to your lights from the common on switch 2, then run 2cores between the two switches to link up the 1 terminal and 2 terminal!
Sy
Edit wookie beat me to it

 

[skotl]

Having looked at your diagram Skoti, I usually wire 2 way switching like this, it doesn't matter as both ways work but for some reason in my head this just looks better.

View attachment 94747

Good stuff. The top half of "my" diagram was actually lifted wholesale from the OP's very first post.

 

[Seadog]

That diagram will not work as a 2way switch as in you will be able to turn all the lights on and off from one switch but not on at one switch and off at the other.

Are you sure? Look again. It is a bit confusing I agree.

 

[brightspark]

post 16 will work ok wired in singles