SmartHome Light Switches - the No Neutral!

Discussion in 'Electricians' Talk' started by Simon Marshall, May 1, 2018.

  1. Simon Marshall

    Simon Marshall New Member

    Hi there,

    I just bought some light switches to replace my old ones, and chose the Koogeek range, as they connect to Apple Homekit and can be therefore controlled by voice/Siri.

    I stupidly ignored the message on the page that said 'requires Neutral wire', assuming my existing light switches had them. From what I'm now learning about, this appears to be quite a common problem facing a lot of people who don't have the time or money to completely re-wire their whole house.

    I've been reading various things online about how to get around this; from using the Earth wire as a Neutral wire, to looping the Neutral wire back into live. The latter sounds more interesting, but I'm only capable of basic electrics (changing old plug sockets, new light switches etc). I've been searching YouTube for video hacks because this seems like a big issue that most people are facing in the UK when trying to upgrade their home to a smart home.

    Attached is an image that I found online - which I *think* tries to explain the neutral wire looping into live to 'complete the circuit' and getting around the 'no neutral' wire problem. Am I correct in this assumption? Or is there literally no way around this except sending all my switches back and finding a brand that works with Apple Homekit AND siri voice enabled AND no requirement for neutral wire....or could this work? Also attached two other images of the actual back of the smartswitches to show what I'm trying to wire in - one being a single dimmer, the other being a single switch.

    My other thought is...I'm assuming the Wifi part of the smartswitch will need power to operate and send/receive signals, and if so, will this potential solution work?

    Any advice appreciated. IMG_1918.jpg
    Screen Shot 2018-05-01 at 12.42.27.png Screen Shot 2018-05-01 at 12.42.12.png

    Last edited: May 1, 2018
  2. rogerk101

    rogerk101 Screwfix Select

    You need smart switches AND smart lights if you're going to do things without breaking code.
    Instead of the switch being used to make/break line to/from switched line (which then powers on/off the light), you need to rewire it such that the wires that fed the old switch now become line and neutral (earth remains earth). These permanent line and neutral now permanently power the smart switch.
    Now for the light. Instead of the light having switched line and neutral, it now needs permanent line and neutral, which permanently powers the smart light.
    The smart switch and the smart light are now both permanently powered and they talk to each other wirelessly.
    Using the above method, you do not have to break the code by using the earth wire as a neutral, and you don't have to pull new wires. All you have to do is a little bit of reconnecting in the ceiling rose (or wherever your wiring terminals are for your light.
  3. furious_customer

    furious_customer Screwfix Select

    Have you thought about lightwaveRF switches?
  4. seneca

    seneca Screwfix Select

  5. Rhoob

    Rhoob New Member

    I always wondered why smart switches didn't use the earth conductor as a return path for the DC electronics but in the absence of finding a reason I put it down to good practice not to have current flowing through the earth wire which I understand is a protective measure for fault conditions.

    Do you have a reference in the wiring regs which prohibits the use of the earth wire as a neutral?
  6. Simon Marshall

    Simon Marshall New Member

    Thanks. That’s very helpful When you say I would need the smart switch AND smart light, are you referring to the light fitting itself eg what I stick the bulb in? assuming not the bulb - although I’m aware of the limitations of bulbs).

    I found an article which explains a bit more about these 2 wire and 3 wire systems.

    In fairness, I chose Keegoo based on price (£42 for dimmer and £35 for standard switch compared to £60 a switch from Lightwave which works out £100 cheaper from what I can tell - although I’m beginning to wonder if all this effort and switching wiring is worth it as opposed to just returning them for a refund and going for the lightwave products. Will have to do some pricing and see what the cost would be to change them and avoid a false economy!
  7. MGW

    MGW Screwfix Select

    I used myhome energenie although does not need neutral does need a deep back box.
  8. RolandK

    RolandK Screwfix Select

    It was the no neutral problem that mainly made me go Philips Hue to replace my old X-10 system.
    Just don't use the earth as a neutral! Not good practice.
  9. Simon Marshall

    Simon Marshall New Member

    In fairness, I think I dived in a little too quickly after reading the product headlines and assuming the ‘easy installation’ bit and neutral wire sounded pretty standard, except when I investigated the wires inside my light switch (after already buying the switches). My assumption being that this sort of thing had been around a good few years and so it must now be plug and play - which is true to some extent - but I’ve learned that I really have to do a lot more homework before purchasing anything.

    I had completely missed that for my lamps, instead of a plug that costs £45 I can get a bulb that fits (e27) that is dimmable, colour changing and costs £22. Might seem obvious but when you start thinking of the solution from the plug socket or wall switch, it precludes thinking of just the bulb itself.

    My second issue is that all my kit is Apple based and I didn’t want to start introducing another platform assistant (Alexa), so I’ve been watching the massive growth and cost reductions for an amazing amount of products that work with Alexa, and any Apple HomeKit products trailing far behind and at a price point that generally cost 4x more. There’s recently been a bit of movement on products for Apple HomeKit, so I figured now was a good time to start converting my home.

    I’ve been checking out the LightwaveRF option, and although it’s 2x more expensive than the Koogeek fittings I bought (which didn’t require a hub), it sounds like they may save me a bunch of work (and money) rewiring my switches and light fittings to incorporate a neutral line, which could be the false economy once I start doing that!

    Does anyone recommend any forums for smart home stuff (U.K. based)?

    Thanks for the replies, guys
  10. tjbond

    tjbond New Member

    I found these guys who do a Live Wire only wifi switch which connects to alexa etc. i bought one to test and they do the job perfectly without a neutral wire thought they were defo worth a mention as it answers the age old problem of no neutral in the uk.
    Hope this helps
    truman29 likes this.
  11. Mr Rusty

    Mr Rusty Screwfix Select

    Philips hue is a good way to go. Intelligent bulbs and a central hub. You can control them from the hue app, alexa, google home, apple, and via small battery operated dimmer switches which you can mount on a wall etc. If you go down the alexa route you can use hue bulbs plus 3rd party wifi controlled adapters (I have KASA smartplug) if you wish to switch plug-in lights etc. In alexa you can group various devices together so a single command e.g. "everything off" turns off all your hue bulbs, wifi sockets etc. This is what I am doing.

    I looked at the automated switches, but in the end figured that hue was still the easiest way to go. There are also 3rd party hue-compatible bulbs which are apparently cheaper - haven't tried them.

    BTW "no neutral" at light switches is a very usual way of installing cabling. I believe only more recently has loop in/out the switch become more common (but I'm not a sparks)
  12. RolandK

    RolandK Screwfix Select

    I now have a mixture of Hue bulbs and smart sockets (Not Hue).
    The smart sockets (Teckin) have their own app but they can't be seen by Hue. I use Alexa which brings it all together in one place as it sees Hue and any other Alexa compatible devices like the Teckins. All seems to work well enough but I find the Alexa voice commands are not yet 100% consistent. Hue itself is solid and reliable. Alexa now has 'Routines' functionality allowing you to launch a string of commands with one word or phrase or trigger it from the app.
    The advantage of the Hue bulbs is you still have your standard switches so can easily revert to standard bulbs should you want to if, for example, you move and want to take it all with you.
    I have tried INNR and Ikea smart bulbs which seem to work fine.
    Last edited: Dec 29, 2018
  13. Rulland

    Rulland Screwfix Select

    Roger, this gives the impression you are US based, in which case your wiring and standards are actually quite below the standards that the UK define as safe, and good practice.
  14. truman29

    truman29 New Member

  15. Mr Rusty

    Mr Rusty Screwfix Select

    I'm intrigued. How do they work? Do they work without an earth as well? Hopefully they do, or surely otherwise they must be using the CPC as a return path.........?? :eek:
  16. truman29

    truman29 New Member

    Judging by the reviews they work just great and also are as easy to install as a regular light switch. I'm just waiting for the Chinese to copy the product and sell them on for a lot less money!. . .LOL
  17. Comlec

    Comlec Screwfix Select

    The are powered by gullibility. Which can usually found in abundance in homes where the owners pay £40 to replace a £2 light switch.
  18. Mr Rusty

    Mr Rusty Screwfix Select

    Have to hold my hand up, we have alexa which we use to control sound systems and hue lights ,mainly. It's the garlic bread - I've tasted it :D
  19. om joshi

    om joshi New Member

    Hey all, this is a really good article. i have the same problem. So i am wondering is there any product economical which can work with 2 Wire Cabling system. As i have no plans to upgrade to 3 Wire system. Highly appreciate your reply as soon as.
  20. MGW

    MGW Screwfix Select

    As I have already said I used MiHome Energenie which don't need a neutral, I seem to remember needs a 5 watt load minimum. So remove a bulb and it auto switches off, also same with power cut, they need a deep box, you can get a slave so can work as wired two way, also dimming version. I have a simple switch because I did not want to wire up for 2 way switching but wanted to be able to turn off in bed.

    You can use up to three remote controls with the switch, plus the switch its self, this does not need a hub, however if you have a hub then also can set up to three timers per day, and select which days of the week the timers are active for, also again with hub you can switch on/off with your phone or PC, and you can use IFTTT (If this then that) with odd functions like turn on lights if bad weather forecast, or add extra timers.

    I selected MiHome Energenie because my central heating also uses MiHome Energenie so all works from same hub, plus two sockets, and an energy monitor. And I selected the MiHome Energenie TRV because it will work with Nest.

    And this is the real thing, what else do you want to do? I use Android phone Samsung and it works well, however if not using Nest then there may be a better option or cheaper option.

    The big problem I found is finding out the limitations before you buy, I could have done with 4 times per day, there seems to be no limit to how many times the TRV head can change temperature during the day, so expected same with socket, but was limited to 3 times per day unless using IFTTT which in turn needs internet. There is a centre terminal on the switch to allow it to be connected to a slave switch working like a two way switch, but instructions as to what the terminal is for is only given in the set that comes with slave switch, the master switch instructions don't tell you what the extra terminal is for.

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