Wiring smart light switch - neutral wire issue

naik420 · Jan 25, 2023

I want to install smart light switch into the wall socket that currently has a normal light switch. The smart switch requires a neutral wire which is not available in the current light switch wall socket.

There’s another light switch not far from this wall socket which does have a neutral wire.

Can I use the live/switched live wire from the current wall socket to connect the L and L1 of the smart switch, and the neutral wire from the other switch to connect the N of the smart switch that I want to install?

Thanks for your help.

littlespark · Jan 25, 2023

You cant 'borrow' a neutral from a socket to join into a switch. They're on different circuits for a start.

It is possible to get another neutral wire to this switch, but how difficult and how messy is down to the wall construction.
If an older house, it might even be in conduit, so easier still.

timhoward · Jan 25, 2023

littlespark said:
You cant 'borrow' a neutral from a socket to join into a switch. They're on different circuits for a start.

I think you might have read it wrong. Both are light switches. He said "socket" meaning "box" I think.

But anyway, as you say there will be a way to do this.

Alternatively, in this situation, if it's the customer's first foray into all things smart I usually suggest using a normal Quinetic receiver at the light fitting, a normal Quinetic Switch, and getting a Quinetic Wifi to RF gateway which makes all original Quintic receivers "smart". Full app and Alexa/ Google Home control is then possible.
Of course, if the customer has already invested in a different system then this idea isn't viable and we go back to a physical wiring solution.

naik420 · Jan 25, 2023

littlespark said:
You cant 'borrow' a neutral from a socket to join into a switch. They're on different circuits for a start.

It is possible to get another neutral wire to this switch, but how difficult and how messy is down to the wall construction.
If an older house, it might even be in conduit, so easier still.

Many thanks. And apologies, when I say socket I meant another light switch box. So the neutral is from a light circuit going into another light switch box.

Plus, on your second point, the wall switch box (where I want to install the smart switch) is on a wall behind which is my loft space so it’s open accessible, I.e. I see the back of the light switch box. Will I need to run a neutral wire from the ceiling rose from the light in question or can I take the neutral from the other light switch box?

Thanks

naik420 · Jan 25, 2023

timhoward said:
I think you might have read it wrong. Both are light switches. He said "socket" meaning "box" I think.

But anyway, as you say there will be a way to do this.

Alternatively, in this situation, if it's the customer's first foray into all things smart I usually suggest using a normal Quinetic receiver at the light fitting, a normal Quinetic Switch, and getting a Quinetic Wifi to RF gateway which makes all original Quintic receivers "smart". Full app and Alexa/ Google Home control is then possible.
Of course, if the customer has already invested in a different system then this idea isn't viable and we go back to a physical wiring solution.

Hi

Many thanks for your clarification and suggestion. It’s a great option. The only issue I see is that Quinetic don’t do dimmer switches, or at least I couldn’t find.

So for now I’m looking for some advice on whether I could use a neutral wire from one light switch box into another light switch box. Both lights being on the same circuit as power to all is cut off when I trip the fuse.

Thanks

timhoward · Jan 25, 2023

naik420 said:
Many thanks for your classification and suggestion. Outs a great option. The only issue I see is that Quinetic don’t do dimmer switches, or at least I couldn’t find.

The dimming module is actually in the receiver (so a dimming receiver is needed). Then any quinetic switch acts as a dimmer switch by holding it in.

naik420 said:
So for now I’m looking for some advice on whether I could use a neutral wire from one light switch box into another light switch box. Both lights being on the same circuit as power to all is cut off when I trip the fuse.

Having read what you wrote above about having access to the back of the wall it sounds as though this is the way to go.
It's possible to do this, but you'd have to take an earth across too, which basically means it's simpler to connect all three and use them, and safely terminate the original permanent live in your new switch position.

davesparks · Jan 25, 2023

naik420 said:
Will I need to run a neutral wire from the ceiling rose from the light in question or can I take the neutral from the other light switch box?

If its possible to run a cable to the light then the best solution would be to replace the twin and earth cable to the switch with a 3 core and earth cable.

naik420 · Jan 28, 2023

davesparks said:
If its possible to run a cable to the light then the best solution would be to replace the twin and earth cable to the switch with a 3 core and earth cable.

Many thanks for your guidance and input.

I drew circuit diagrams to understand how the light circuit works where the neutral is at switch and where it is at the bulb (ceiling rose). Since both my light switch in question and the other light switch are on the same circuit, i.e. same board trip/ fuse, I simply brought the neutral wire from the other switch to the switch in question. It works perfectly. I didn’t have to do a whole lot of rewiring, which I could do, but saves me time and effort getting into tight loft space and all.

brianmoooore · Jan 28, 2023

I've not read through this post in any detail, but there can be a massive void between what "works perfectly" and what is safe and compliant with regulations.
What type of wire did you use for this neutral link?

naik420 · Jan 30, 2023

brianmoooore said:
I've not read through this post in any detail, but there can be a massive void between what "works perfectly" and what is safe and compliant with regulations.
What type of wire did you use for this neutral link?

Thanks

I used the proper cable, similar to the one used for wiring the switch (grey tough one)