Smart Wi-Fi Light Switches that require N

[theballoonman]

Hi, these switches that need the N (to power the wifi chip), can the N be taken from a plug socket which is closer and easier to route than from the ceiling rose (well i don't have a ceiling rose actually as they are outside wall lights)? I did read it has to be the same circuit but as I understand its just to power the unit, would that work?

 

[bernardgreen]

can the N be taken from a plug socket which is closer and easier to route than from the ceiling

It could be but the problems created would make it not a sensible idea. Frequent tripping of RCDs being just one of the problems.

Do the job properly or live with normal ( and most reliable ) switches.

 

[ericmark]

Hi, these switches that need the N (to power the wifi chip), can the N be taken from a plug socket which is closer and easier to route than from the ceiling rose (well i don't have a ceiling rose actually as they are outside wall lights)? I did read it has to be the same circuit but as I understand its just to power the unit, would that work?

No it's called a borrowed neutral and has been against regulations for as long as I can remember.

The problem is should the socket supply be worked on it can become live from the lights.

 

[theballoonman]

No it's called a borrowed neutral and has been against regulations for as long as I can remember.

The problem is should the socket supply be worked on it can become live from the lights.

Ah okay, but the N is safe to come down from the ceiling rose, i.e for the light that is being worked on?

As it happens I'm trying a no N required smart socket so I'm hoping this works with any kind of N, it uses some little capacitor I'll call it in the rose to prevent led's flickering.

 

[ericmark]

I used Energenie smart light switches, with large bulbs OK, but with small G9 LED been a problem. They don't use a neutral but clearly there must be a small current through bulb when off, has to get power from some where.

So can flash when off, cured using a load capacitor, and can shimmer when on, this bulb was a problem this one worked OK, one of the larger bulbs failed so I took apart, found dry joint, fixed and now back in use, but while apart realised it has a smoothing capacitor after the bridge rectifier, current control also a capacitor.

The problem is no one says how an LED works, so it is suck it and see, ordered spares when the one failed and also quartz with 4 of the and 1 quartz they worked OK, but not all 5 LED of that type, and this type was much whiter and looks odd if you mix, so now have 5 small spares, 10 quartz spares and 4 large spares and only 6 bulbs of that type in whole house. Can't see I will ever run out of G9 bulbs.

Also had some problems with GU10 but kitchen lights are not using electronic switches so swapped between kitchen and bedroom. I use electronic switches so I can use remote control from bed to turn lights on/off. I can hear relay in the switches.

Also found they interfere with each other, 3 work fine, but 5 started to have a life of their own, and would need to switch off lighting power count to 10 and switch back on again to get lights working again.

Not got any needing a neutral but I would assume they work better. Some switches in this house have a neutral and some don't, also have one 4 gang switch with two lines and two neutrals in it both from different RCBO's which did cause a problem as it would trip the RCBO every so often until found fault and swapped neutrals to correct circuit.

With RCBO's you have no option if you borrow a neutral it will trip, with one RCD feeding many MCB's if the same RCD you can get away with it, in as to it will work, but it is dangerous as a circuit you think is dead can become live when you turn on the light, rather shocking when you find out. So clearly not allowed.

However often found when the lights have been split upper and lower floor and you have two way switching on stair lights.

Not had any problems with larger bulbs, BA22d and E14 even when the latter said non dimming have worked OK without a neutral.

 

[wiresandwood]

You could try Shelly gear for this, which has two relevant products that can be installed without a neutral and connects to your wifi.

Simple switch: https://shelly.cloud/products/shelly-1l-single-wire-smart-home-automation-relay/
Dimmer: https://shelly.cloud/products/shelly-dimmer-2-smart-home-light-controller/

Both of these can run with just a live feed, or if you have access can be wired into the ceiling where these is a neutral and then have the switch connected to them so that the light works as it did before, but cannot be "turned off" at the switch. I have some of these in my house and find them excellent. There's an app that keeps it simple or a more advanced mode where you can integrate them into a home automation system.

The "no neutral" wiring requires a bit of current to be leaked through the light circuit, which can make small loads (e.g. a couple of LEDs) glow. They sell a small addon that you can connect across the light fitting (wiring diagrams are in the instructions) which takes some of the leaked current away from the fittings: https://shop.shelly.cloud/bypass-wifi-smart-home-automation.

They're keenly priced and there's a UK distributor here:
https://shellystore.co.uk/

 

[Friday round]

@NickV The Shelly Dimmer2 and the neutral bypass may work for me. I’d like to put in some colour changing lights into the kitchen and automate scenes based on time of day or night. I’d like a physical switch that replaces the existing one that can turn on/off lights and override the dimming settings. What are compatible switches?

 

[wiresandwood]

Hi @MarkMann,

The Shelly units can use any physical switch, including existing rocker ones. As the switch is connected to the Shelly unit not the power feed it is separated from what the light actually does, so they can be configured quite extensively so that they either take actions based on whether the switch is on/off or whether the switch has just changed position. This can be a bit confusing if you start to combine it with other actions as (for instance) if you have an on/off switch in the off position but turn the light on in the app that can be counter intuitive. If you want to make it more intuitive for other house residents/guests I can recommend getting some retractive switches which just click then return to the same position. You can then do (for example) click for on, click again for off or long click to select the next scene.

I can recommend Schneider grid retractive switches for a nice appearance and quality click feel, you need to order both the retractive switch module and the faceplate in order to do this, but that's all you need for something that screws onto a UK backbox and they're quite cost effective in white (and also come in lots of other finishes). For each switch you need one each of these items:

https://www.edwardes.co.uk/products/schneider-get-gug102rw-10ax-2-way-retractive-grid-switch
https://www.edwardes.co.uk/products/schneider-get-gug01g-1gang-grid-plate-with-grid-white-plastic

In terms of coordinating multiple lights what I think you're describing is scenes, which I believe the Shelly app allows you to set up. I don't use the app myself as I have a Loxone system and just use the Shelly stuff for adding in extra things like lamps and lights which aren't yet on the automation system.

There's an official Shelly facebook group here which has a lot more info and chatter. It's also a place you can see amateur electricians from all across the world share pictures of their attempts to burn their houses down with their attempts at awful, unsafe wiring.

https://www.facebook.com/groups/ShellyIoTCommunitySupport/