Changing a 2 Gang 2 Way switch to a 2 Gang smart switch Ask questions and find answers to many subjects relating to electrics and electrical work

[PurpleHeadedWarrior]

Hello

I am trying to change my kitchen light switch which is a 2 Gang 2 Way switch to a 2 Way Zigbee Smart light touch switch, what wires should I connect to where? Any and all help greatly appreciated, Thank You

[Mr White]

Make and model (And link if possible) of the switch you have would be good.
The reason I ask is that looks like a 2 gang switch, not a 2 way switch.
Can't say I have heard of a 2 way smart switch. But I am willing to be proven wrong.

[PurpleHeadedWarrior]

Hi Mr White,
I think you’re right it’s a 2 gang switch, it’s for the kitchen which has 2 lights but are only controlled from this one switch, It’s a Zigbee Tuya Smart touch switch brought on AliExpress, it’s doesn’t need a neutral wire

[ericmark]

I the main two way smart switches are wired completely diffrent to a mechanical switch.

I have seen a few methods, one uses a senor wire, extra low voltage, another uses wifi to connect the second switch, the second switch has a 230 volt supply, but no wires connect it to the master switch.

I have watched a video, but never tried it, and I have found with smart devices they are all diffrent, if I was on a PC maybe I could find the video, but not easy with my tablet.

[ericmark]

I the main two way smart switches are wired completely diffrent to a mechanical switch.

I have seen a few methods, one uses a senor wire, extra low voltage, another uses wifi to connect the second switch, the second switch has a 230 volt supply, but no wires connect it to the master switch.

I have watched a video, but never tried it, and I have found with smart devices they are all diffrent, if I was on a PC maybe I could find the video, but not easy with my tablet.

[PurpleHeadedWarrior]

Hi
I’m thinking that the 2 L1’s would go to L1 and L2, would the 2 Comm’s both go to the L ? Or would that be wrong and cause the mcb to trip?

[Mr White]

Your existing switch is 2 gang 2 way, BUT it is being used as 2 gang 1 way, in an odd configuration.

You have 4 wires (all red) and your smart switch has 3 terminals.
L L1 & L2

L is for permanent live, L1 & L2 are for the respective switches.
You need to connect the smart switch correctly first time as if you get it wrong it may simply not work, or it may let out the smoke.

It matters not what colour the wires you have are (all red in your case) as you need to identify which is Live and which is switched live. If you had a way of doing this, you would have done so by now, so I can only suggest you get someone competent in to the job for you.

Sorry it is not the easy answer you were hoping for.

[ericmark]

I wish I could say A to 1, and B to 2 etc. But the switch labels seem to have gone silly, so you have to read the instructions that come with the switch.

I see 4 wives on the orignal switch, which I would say two are feeds, and two are supplies to the lights. The two supplies may come from the same MCB/RCBO or they could be from diffrent ones.

What we want to avoid is a borrowed neutral as it is called, really a borrowed line, so test one is turn off the MCB/RCBO's in turn and ensure both lights are from the same one, if not your stumped.

If they are both on the same breaker then one feed will not be used and needs to be put in a connector or some thing safe.

I look now at your pictures, and wonder where the two way came from, as they don't seem to be two way wired?

[PurpleHeadedWarrior]

Hi EricMark,

Thanks for your reply, I have checked and tested the lights by turning the mcb off, and by doing that both the lights stay off.

[Mr White]

............as I said previously, you still need to know which is the live and switched live.
Without a safe means of testing, I am sorry to say you are a danger to yourself and others.

Don't take the above the wrong way, I don't want to find out that you are dead (electricity will kill anyone, you don't get a 2nd chance) I really do wish it was as easy as put this wire here, that wire there and all will be fine and work, but sadly it's not, which is why as before, I suggest you get someone competent to do the job for you. I do not know who you are, so I don't really care, but what I don't want is for you to do something silly and kill yourself or worse still, kill someone else because of what you have done.

[ericmark]

Mr White is likely correct, I am very aware people will give it a go, so I am reluctant to say get an electrician to do it for you, as that often means people stop asking rather than they get some one to do it for them.

As a retired electrician I lost access to the test equipment I would have borrowed from work, also my son in same trade has the test equipment I did have, so I am very aware of the cost problem.

A reasonable clamp on ammeter costs around £35 or more, I say clamp on as measuring current with non contact is safer, less likely to have a short and ionise the atmosphere.

The insulation tester again minimum price seems to be around £35.

Odd could not find a cheap low ohm meter (should use at least 200 mA on the test) neither can I find a cheap loop impedance tester, or a RCD tester, to get them looking at £350 plus.

But this means to get the basic tools costs around the £70 mark, and for £70 you can likely get an electrician to do the job for you.

We see the Chinese smart switches a lot, where unlike the traditional British switch, the multi gang switch has a single live feed, however my British smart switch [attachment=0]light_switch.jpg[/attachment] is not much better, it has three terminals line in, line out, and S. And the S terminal is not 230 volt it is a sensing or trigger wire.

So we have to read the instructions carefully, there is no longer a standard wiring diagram.

Out of 5 smart switches, I have just 2 still working, they have not stud the test of time, they were OK for a couple of years, then they started to fail, so today I use smart bulbs, not saying they last longer than smart switches, but they are far easier to change.

So I walk to bottom of stairs, and say hey google turn on landing lights, and they come on, why mess around with switches?