3 storey house sonoff smart switches and 2-way wiring Ask questions and find answers to many subjects relating to electrics and electrical work

[simon88]

Afternoon all,
I have reading all I can on 2 way switches on here but I am still confused by the hallway light switch wiring in my house.

I have replaced the majority of my light switches in my house with Sonoff Smart switches and wish to now replace the hallways. I have attached a picture of the following:

-Ground floor 1 gang controlling first floor light
-First floor 2 gang controlling first floor light and second floor light
-Second floor 1 gang controlling second floor light

The sonoff switches require a neutral and live and 1 or 2 live outs to the light fitting. The light fittings themselves have a single live/neutral/earth.

[Mr White]

You have standard 2 way switching.
A normal sonoff switch can not operate 2 way switching.
Sonoff do not make a 2 way switch, they do however make a unit which you can add to an existing 2 way switch, but you need access to the existing cabling and the and somewhere to put the unit.

Having said that, if you have a "smart speaker" you can ask that to turn the light on or off.

[ericmark]

I have not used sonoff as yet, but as far as I can tell the unit is connected to the ceiling rose not the light switch and the S1 and S1 wires become the switch wires so you are it seems switching extra low voltage at the lights.

My son has suggested I use sonoff or another one which does the same, but for me only really an options for upstairs lights as no access to behind ceiling rose on lower floor.

Other makes also have problems with two way lighting, the standard way to use two way lighting is [attachment=0]two-way-real.jpg[/attachment] shown, there are three wires between the two switches line in bottom and line out top, the middle wire between the two com is the problem, in the diagram shown it carries 230 volt.

However with electronic switches this includes dimming switches and smart switches that middle wire is a data wire, and connects between the S terminals of a slave and master, and it is because you have slave and master switches that we have a problem, all the two gang switches are either slave or master, they never seem to make a switch where one switch in the plate is slave and one switch is master.

I think however you could use a slave/master combination but the cost is much more than using the sonoff for example Energenie.
Gateway £70 CODE: MIHO001
Slave one gang £15 CODE: MIHO043-S
Two gang master plus one gang slave £60 CODE: MIHO090
So £145 for all three, compared with around £15 for two sonoff units fitted in the ceiling, and all the non neutral switches and Energenie does not need a neutral, have a problem with some LED lamps, the standard BA22d bulb seems to work OK, but some of the smaller bulbs specially the G9 have problems one when switched off they can flash, although a load capacitor can cure that, but also when switched on some flicker, only cure I have found is swap one bulb for quartz.

Using switches which need a neutral is far better, if you have a neutral at the switch, many of the cheap wifi connected switches have a single supply to all switches on the plate, that can also cause problems where the lights are supplied from different fuse/MCB/RCBO in my house when I first fitted all RCBO protection I found one switch where the wrong line was used (technically called a borrowed neutral) lucky I was able to correct at the light switch, but I know I have a 4 gang light switch which has two line supplies one for upstairs and one for down stairs so could not use a switch which combines all lines feeds.

Note we call the phase conductor in single phase line, as the neutral is also considered as live just in case you wonder what I means when I say line.

[Mr White]

but as far as I can tell the unit is connected to the ceiling rose not the light switch

Not wanting to "shoot you down" But you are in error.

Sonoff do indeed make light switches, as well as the little units you are presuming he has. If you read what simon88 actually typed, you will note that he has already changed most of his switches to sonoff smart switches.

All he wants to know is how to connect them to what is currently 2 way switching.

I would also like to take this opportunity to point out that this is a DIY help forum, and as such 99% of posters do not understand what you mean, if they did, they would not be here asking what to you and I are simple things.

Your help is most appreciated, but you would get better responses if you stopped bringing yourself into it, with your Energenie stuff and what you have done with it, there are other makes out there too.

I understand that you and your son are better qualified than most, but at the end of the day, this is a DIY help forum.

[simon88]

Thanks for the reply's.

Sonoff are capable of simulating 2 way switching in their scene settings - eg if I press on one switch it can trigger another and vise versa which I would be happy with; a 2 gang switch can be installed with only one output and control another light switch elsewhere.

On that basis based on the wiring above how would I go about changing the the first floor and second floor lights to one way circuits?

I plan on terminating the ground floor 2 way switch as pictured and covering with a RF switch which could then control all switches remotely.

[Mr White]

Two way switching is accomplished by connecting the first switch to a second switch.
This is done by running a 3 core and earth cable from one switch to the other.
The last switch of the two switches will only have 3 cores.
The first switch will have 5 cores (In neither case am I counting the earth)

To make two way switching to one way switching you need to remove the interconnecting cable.
The interconnecting cable will be the 3 core cable that has one core in the top terminal, and one core in each of the lower two terminals.

The two cores that remain will also be in the lower two terminals, but they will NOT be part of the cable that that has a core in the top terminal.

I would suggest you put an individual connector block on each one, so you can if needed use them at a later date.

[simon88]

Just popping on to say a massive thank you for your assistance - it made complete sense after your explanation and I was able to achieve what I wanted.

2nd floor - 1 gang Sonoff switch controlling 2nd floor light
1st floor - 2 gang Sonoff switch controlling 1st floor light with routine to control top floor (simulated 2 way switching with no noticeable delay)
Ground floor - 3 gang RF switch to control all 3 floors; a revelation in a town house!

I have terminated the unused wires in connector blocks incase they are needed in the future.

Many thanks again!
Stay safe.

Two way switching is accomplished by connecting the first switch to a second switch.
This is done by running a 3 core and earth cable from one switch to the other.
The last switch of the two switches will only have 3 cores.
The first switch will have 5 cores (In neither case am I counting the earth)

To make two way switching to one way switching you need to remove the interconnecting cable.
The interconnecting cable will be the 3 core cable that has one core in the top terminal, and one core in each of the lower two terminals.

The two cores that remain will also be in the lower two terminals, but they will NOT be part of the cable that that has a core in the top terminal.

I would suggest you put an individual connector block on each one, so you can if needed use them at a later date.