Anyone on here had their House re-wired with Neutral Wire?

Many of the ‘smart’ switchboxes require a neutral wire to operate properly. This makes sense as the electronics need to draw power even if the lamp is turned off. Yes there are switches that do not require a neutral wire, but those are only a few.

Here in the US (and maybe in other parts of the world), it is not common to have the neutral wire in switchboxes. Furthermore, in Illinois (Chicago), the building code imposes that all electrical wires be housed in metal tubing. This is in contrast with other states. Pushing a neutral wire through a tube seems easy … until that tube has a 90 degrees elbow, and the whole thing is housed inside the wall.

I’m curious if any on here had their house (or few switches) re-wired and how much of an effort and $$$ that is.

Hi .
i am from South africa. we have the same issue . i had to completely rewire a part of the house.
by doing that i had removed the steel piping. and replaced them with pvc conduit. but you still have the issue of 90’ turns inside the wall . this side our walls are all brick and mortar. so i pulled all single lines out and replaced them with 1,5mm2 flatex cable. for light switches and 2,0mm2 for all plugs. and then had my neutral there. i am running Sonoff T1AU switches.

Another SAffa here. I’ve been told it’s actually a requirement to have neutral wires, but builders and their electricians saved on costs and left them out as they figured it won’t be used (well, that was the case a few years ago). I think now that we have more and more smart devices, newer buildings will have them in as intended.

I ended up doing individual points in my house as needed. I would use some electrical tape to tape up a new live and neutral to thge existing live wire, then use the existing live wire as a guide an pull the new wires through the conduit.

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May I throw in a curve ball thought?

If you’re facing the thought of re-wiring or adding a neutral, which I’ll assume will be a 1.5mm single, why not consider pulling out the large mains (110vac or 220vac) wires from the switch points and pull through a smaller 4 core data cable?

So that you can have the choice of a massive range of extra low voltage (12 to 24 vdc) fully wired device.

Some only need 2 cores and some need 4 cores, so pulling a 4 core cable, like a good quality two twisted pair will mean that you can open up your options.

For example, the Velbus glass panels are not only buttons, but each one has a full HVAC thermostat, 4 independent timer set points which can trigger button events, sunset and sunrise timers, full led feedback.

The top of the range, of either type, have OLED displays, which openHAB2 can push messages onto.

Like this RGBW edge lit Oled panel.

I’m living in an rented apartment so rewiring by opening the walls was out of question.
But I had power outlets near the light switches so the electrician could just rewire the neutral wire from the power outlet socket to the light switch socket.
Took him less than half an hour for three light switches and was quite cheap (cheaper than the HW cost of the smart light switches).

Good thinking about doing 4 ipo 2 wires. The only place I have 4 wires is for the thermostat and phone lines … I thought of ‘Pulling’ wires, but that is not an option as there are junction boxes behind the walls … if I pull hard, I’ll destroy something :frowning:

As to getting the neutral from boxes that also have an outlet, yes, I’ve done those already, but there are not many like that. The problem is where the damn contractor/electricians cut corners to save few pennies …


you were very lucky then.

It may be different regulation where you are, but in the UK it is not permitted to bridge circuits.

In this case, the socket / outlet circuit to the lighting circuit.

The reasoning is quite simple.

With the push towards RCBO circuit protection, the circuit load must be balanced on both sides of the RCBO.
If the current draw on the live output of the RCBO is different (even by 3ma) to the returning neutral, the RCBO will disconnect the circuit in under 30ms (Sometimes as quick as 3ms)

Technically speaking, as long as the entire installation has an earth leakage RCB protecting it, with normal fuses or MCBs per circuit, you are perfectly safe.

I just wanted to provide the information in case anyone with RCBO protected circuits attempts to “borrow” a neutral from a different circuit and wonders why one or both RCBO switch off the circuits.

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Did they “cut corners”, or just complete the installation to a minimum or older standard?

Interesting … in order for the mains/supply to detect there is a difference between the currents on the live/neutral sides of the outlet, there must be some ‘smarts’ built in the circuit. Not sure the current hardware in the US has such smarts. Any idea how this is accomplished in the UK ?


Are you saying that the UK is ahead of someone for a change?

So, I’m going to assume you are completely up to speed with MCB and RCD protection, so If I say that an RCBO is a combination of both that should make sense.

I think I am right in saying that our consumer boards can now be configured as follows.

Whole system must be protected with a over current device (Normally 80amp or 100amp)

Then each individual circuit should be protected with a combined over current breaker and earth leakage (balanced load) device, known as an RCBO.

How they work is a dark art that I’m not aware of, but here are some links to suppliers if you want to investigate further.


The different “Types” refer to their over current or In-rush tolerance.

Type A being the quickest to react, and Type C being the slowest.

There are some very funky “smart” circuit breakers out there now.

There are coil activated breakers, which are like “safe state” relays.
When a charge is applied to the coil, it pulls the circuit breaker.

There is also a range of “fire protection” circuit breakers, where if the breaker goes over temperature, it not only disconnects the electrical circuit, but it also releases a fire suppressing gas.
There is a remotely trigerrable version too, which I think is a combination of the two types.
(Release coil and a gas canister)

Here are some interesting articles

In the USA, arc fault circuit interrupters have been required by law since 2008. With the 5SM6 circuit breaker, Siemens is the first manufacturer to introduce this kind of device onto the European market.

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Thank you, I’ll read those links later tonight and ‘educate’ myself a bit.

Thinking a bit more about this, and typically in the US (in contrast with other places I’ve visited), there are two types of switches:

  1. Those that control a light/fan attached to a ceiling. These typically have a neutral in the box
  2. Those that control an outlet (to power lamps). These typically do not have a neutral in the box.

When you buy a house, or rent an apartment, typically some rooms have lights attached to a ceiling, others do not. For the former, the wall switches control the ceiling lights. For the latter, the wall switches control the outlets. Also, typically all outlets come in dual configuration, one is always powered, the other is always controlled by a switch.

Thus, it makes sense that, for those switches that control ceiling lights, a neutral wire ‘should’ be available in the box. For switches that control outlets, typically there is no neutral in the box. Thus, if we believe this to be the case, then we have two options:

  1. For switches powering ceiling lights/fixtures, replace with smart switches.
  2. For switches that control lights, leave those alone and use smart plugs instead.

My home has in excess of 40 switches … and I must ‘prioritize’ which get replaced first.

Good to know - I was not aware of that. Since I paid an electrician for the work I just assume that he did it in a safe and legal way :thinking:

That’s one of the things many Europeans will never understand about U.S. homing, why are you always talking about and looking to replace switches ? (many German users here because of openHAB’s origins).
Over here, it’s modular: you have a physical switch, and that you can ADD a smart actuator to (to attach both to, light and switch), but you KEEP the switches. No need for smart plugs.
And Neutral should usually be available at all fixtures, shouldn’t it ?
So unless you have implemented previous-gen “smart” switching such as 3-way switching, you should be able to reassign one of the wires going from the fixture to the switch to become a neutral carrier (usually - I know there’s exceptions).
And yes I can hear all the electricians start howling …

PS: and why do even your latest smart switches look like stuff from the 70s …
PPS: not sure what Stuart (@MDAR) counts as :wink:

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@mstormi … Well, one thing I’ve seen in the US often, is whenever there is a new product released, somehow there is always concern to make it compatible (drop-in replacement) with current technology. All switches in the US use the SAME housing (box that goes inside the wall), and have the same ‘footprint’. In Europe and other places, there are too many variations/designs/choices, even from the same manufacturers.

Here is another example: Every few years, you can see new models of dishwashers/refrigerators, and other appliances. Often though, while the outside was upgraded, the interior parts change very little from one generation to the next. This helps keep the inventory/cost of spare parts to a minimum, while giving the end-user the perception of something new (on the outside at least). In the US there is a big ‘push’ for standardization … whether it is the width of a refrigerator, the current rating of a switch, or the size/topology of plumbing components.

So yes, it’s a bit complicated/different on this side of the pond … hopefully we can all learn from one another and converge on something common … except maybe Metric vs. Imperial, and A4 vs. Letter paper formats.

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That’s really interesting, where as in the UK it’s typically exactly the opposite.

Ceiling light switches only switch the live side and rarely have neutrals available at the light switch.
(The switch wire consists of a live send and return, from the ceiling rose, which has Live & Neutral IN and Live & Neutral OUT (to the next ceiling rose))

Whereas, power outlets require a Dual pole switch, to completely isolate the outlet when it’s off.

That said…

If, the outlet is specifically for lighting, we would fit a 3 pin 5amp round pin socket (as opposed to our standard 13amp square pin outlet)

So in theory, if your Lighting socket is on the same circuit as your ceiling light circuit, there would be no risk at all with taking a neutral from the socket outlet.

We need clarification, but I think the Dutch use a slightly different circuit allocation method, because they too have (for example) a 3 way round back box, into which you might find

A permanent mains power outlet
A switched mains power outlet (for lighting?)
A switch assembly

But I’m not aware of the circuit breaking method required.

For example, is the permanent socket on a different circuit to the lighting, or is it 1 circuit per room ?

I understand both, but I wouldn’t program a space craft… :wink:

Reading @JB_63 comment, (#13) it’s possible that you’re referring to a Lighting outlet, rather than a permanent power outlet.

I hope my reply to his comment can put your mind at rest.

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A small disclaimer if I may…

My comments are based on what I have observed in my house. I am no expert electrician. The one additional complication in the US is that each state (50) has their own ‘building code’ … I lived in Michigan for few years, and there the cables running behind walls did not need any special protection. In Illinois (where I am now), all behind-the-walls cables need to be housed in steel tubings.

Here is another thing: Typically for installations near water (dishwasher, in-sink garbage disposal, bathroom, …) the power outlets must have a ground wire connected. In many installations I’ve seen, the ground wire is omitted and there is a GFCI breaker instead

Not sure if the code allows it but when you think about it, a GFCI outlet should be more expensive than a piece of ground wire.

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I wouldn’t dare comment :wink:

I see - you standardized on the 70s look. SCNR :wink:

In the UK, that’s one small step for (a) man, from space craft programming to Home Automation… just ask @chris


To add two more data points. I’ve lived in Texas and currently live in Colorado. In both cases conduit is not required unless the wire is run outside the wall, and I don’t know if it’s code or not, but there is a neutral run to all locations (3 wire Romex). In cases where the neutral is not in use, like behind a light switch, the neutrals are all wired together with a big wire nut.

Because frequently there is not enough room in the box behind the switch to add a Shelly 1 or the like. They are all packed to the gills with neutral wires all twisted together. :wink:

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