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Smart Light Switch but one live wire with old switch

Postby packerm » Sun Sep 26, 2021 9:47 am

Hi
I recently bought a smart light switch to replace a double normal light switch but am a bit confused with the wiring requirement

So on the instructions for the smart light switch it has a live wire coming in and then red wires coming out of L1 and L2 (plus a single neutral wire).

So that's all fine but now looking on my old switch I have what I assume are two seprate switches behind the plate and a a single live wire going into each and a single neytral wire on each as well. So I have two red wires and two black wires

So my question is how to I wire that into the new smart switch?
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Postby Mr White » Sun Sep 26, 2021 8:16 pm

The good news:
Yes, you do have 2 separate switches.
Yes, you do have 2 lives.

The bad news.
Those two blacks are NOT neutral* They are switched lives.
Most smart switches require a neutral, as you have no neutral the switch you have is not suitable in this case. You can get a smart switch that requires no neutral, but they appear to be very problematic.

If it helps:
* If you connect live to neutral there will be a big bang.

When your house was wired, there was no such thing as a smart switch, so there is no neutral at the switch. My house is wired the same.
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Postby packerm » Mon Sep 27, 2021 6:57 am

Thanks fo the reply and help.
So I assume there's no point in me just using one of the red wires to go in to the live terminal on the swtich, then using the two black wires in L1 and L2, i.e. I assume the switch just ain't going to work without a neutral wire?
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Postby Mr White » Mon Sep 27, 2021 10:07 am

If your switch did not require a neutral, why did the manufacturers design and build it with a neutral terminal?

You are not alone in your problem, your question is quite a common one, as I also said, I too have the same problem that you do, I opted to use smart lamps.
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Postby ericmark » Tue Sep 28, 2021 10:38 pm

I used Energenie MiHome switches which don't need a neutral, however had 5 switches now down to 2, as switches failed after a few years, so slowly moving to smart bulbs.
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Postby packerm » Wed Sep 29, 2021 7:03 am

Ta for the info all. Trying a Broadlink switch that requires no neutral so we'll see how that goes (and how long it lasts)
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Postby ericmark » Wed Sep 29, 2021 7:30 am

I think Lightwave also do a smart switch which does not require a neutral, however there seems to be a problem with some LED bulbs, there are two problems, some bulbs will flash when switched off, and some shimmer when switched on.

The flashing can be stopped with a load capacitor on the bulb supply, but the shimmer is caused by the switch and bulb interacting with each other, some bulbs have a smoothing capacitor built in which stops it, but nothing on bulb says which is which, so trial and error is only way.

In the main physically large bulbs seem to work OK with a wattage over 5 watt each, small bulbs like G9 seem to have more of a problem.

However using smart bulbs removes the problem, but not found G9 smart bulbs. I did find some physically larger G9 bulbs that worked with the Energenie switch, but could not fit the covers on with them fitted.

I have one remote control that will work with zigbee bulbs, but have failed to find more remote controls. This means I need to use phone to control, or PC with a emulator running, and it is slow to load so not ideal. However with right bulb I can alter the colour temperature and colour so far better control with smart bulb than with switch.
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Postby ericmark » Tue Oct 05, 2021 3:24 pm

Since last reply I have tired using this smart relay [attachment=1]DSC_6061.jpg[/attachment] it allows me to use either the light switch or the smartlife app, it does need a zigbee hub, the unit is a double so [attachment=0]DSC_6059.jpg[/attachment] so I have split the lights to 4 outer and one inner, not on ceiling yet, but the test on bed to see how it all worked was great.

I will likely get more, as they fit to lamp not switch, and it means does not matter if I use wall switch or app to change state of lamps.
Attachments
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DSC_6061.jpg
ericmark
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