Smart light switches everywhere - Here goes...

[nadimaj]

Lighting diagram attached. Go easy. I'm not a qualified electrician but am an uber geek when it comes to general electronics and I work in IT (obviously).

Due to start a strip/rebuild project soon and will be installing wall mounted smart switches for all the lights in the house. Yes, there are no-neutral smart light switches available (though not by this manufacturer) and there are a gazillion ways to controll lights but this particular way satisfies a whole bunch of other needs with regards to my choice of home automation. I.e. there's a bigger reason behind using this exact switch.

My standard design for each room is to have a spot light ring, centre light and LED lights (inside coving). LED lighting needs some additional planning but enough to say that I want to install the wiring for the transformers now. Each room's lighting will come of a separate breaker.

If you're an old-hat sparky, some background....smart light switches need to be powered up as if they are small computers (i.e with a Live and Neutral). From the switch are L1, L2, L3 (outputs). The wiring is obviously not simple when compared to a good old fashion switched Live circuit, so I've been busy working out what the best way is of doing this. Please see my diagram and offer me your views on legality/safety plus any tips, warnings, suggestions for type of wiring, connectors, junction boxes. Given there's potentially 4 x 3 core sleeves going into the backbox, I'm looking for a smarter solution. Remember, this is a new build, I can put whatever I like behind the walls or in the ceiling.

Thanks!

 

[bernardgreen]

First observation is your error in where you are putting the Live and Neutral to the switch

Make sure that you can operate some lights when the Home Automation system shuts down or becomes erratic in operation.

 

[EFLImpudence]

Lighting and your diagram are not 'ring' circuits.

'Ring' is not another word for 'circuit'.

 

[bernardgreen]

I think the OP means a ring ( circle ) of spotlights around a central lamp.

 

[EFLImpudence]

Ok, apologies but it is an often used mistake.

 

[bernardgreen]

Ok, apologies but it is an often used mistake.

I was being a bit harsh , sorry.

 

[EFLImpudence]

No problem. Fair enough if I was wrong.

 

[bernardgreen]

EFL is right to show the Neutrals to lamps running next to the Lives to the lamps. This will significantly reduce radiated EMI ( 50 Hz ) from the lighting cables.

 

[nadimaj]

First observation is your error in where you are putting the Live and Neutral

Oh, great start. Thanks. Will update that

 

[nadimaj]

EFL, though this has the advantage stated by bernardgreen (which id like to find out more about), that's an incredible amount of wiring in the backbox. I would like to avoid jam packing thr back box in favour of junctions boxes in the ceiling. Thoughts?

 

[nadimaj]

Sketch..

 

[ericmark]

I fitted 5 smart light switches, now only have 3, with 3 one in each bedroom so I can turn lights off in bed they seem to now work well, but with 5 they had a mind of their own. Why google nest mini started to behave I don't know, but with 5 smart light switches I would say hay google turn off radio and it would reply turning off 5 switches and put us in darkness, hay google turn lights back on, got reply don't know how to do that yet.

We would gets lights which would not turn on, and lights which would not turn off, and I would have to go to consumer unit in what was the garage under the house, so go out side to turn off RCBO count 5 and turn it back on again. Be warned the smart switches can be a real pain, as said removed two down stairs and rest seemed to then behave them selves.

 

[EFLImpudence]

I haven't looked at your sketch yet.

that's an incredible amount of wiring in the backbox.

It really isn't. Four cables, twelve wires aren't that many.
Although, obviously if you only have a 16mm. back box, you probably won't even get your switch in.

I would like to avoid jam packing thr back box in favour of junctions boxes in the ceiling. Thoughts?

Junction boxes must remain accessible if they have screw terminals.
Maintenance-free JBs may be hidden but you won't really want that with what you are doing.

I have used a 'wiring centre' in a loft but that entails running all the cables to it - as in normal switch drops; not just half of each circuit. You won't be using singles in conduit, so likely and you will still have as many cables to the switch.

 

[EFLImpudence]

Have looked at the sketch.

No - terrible.

 

[SUNRAY]

EFL is right to show the Neutrals to lamps running next to the Lives to the lamps. This will significantly reduce radiated EMI ( 50 Hz ) from the lighting cables.

Thank you Bernard, It's very gratifying to see others now saying the same thing I was being criticised for a few years ago.