Distribution Panel Wiring for House

[Raks]

I am planning a rewiring and re plastering of a house so I have the opportunity  to rethink and plan  whole wiring circuits with future home automation possibilities (not much time to design and  install a home automation system right now). So I have few options:

The domestic traditional wiring system for a house which separate circuit for  each area connected to the consumer unit.  In this option there are several sockets or lights in one circuit.

There is an alternative more expensive  to install,  commercial model wiring system which circuits run almost for each sockets or lights individually from a distribution board, so you have a centralised control panel of the all power outlets and lights as well. This options seems complex but more manageable if you are planning  a hard wired home automation systems which I am considering not now but as a future upgrade.

 

What would you suggest  for rewiring when considering  hard wired home-automation-ready option as well, if I would like to go for a distribution style wiring system by running cables most of the lights, switches and sockets individually  (and some extra network, sensor cables as well) then make all  necessary connections  in the distribution panel ?

 

[joth]

I'm using a mix: wiring every light circuit back individually (radial layout) but putting the sockets on a traditional ring main.

I don't care much for automating sockets and the odd one where it makes sense isn't going to be a critical component so a sonoff type plug in WiFi switch will be fine. Lighting on the other hand I want to be rock solid and future proof for upgrading (as I don't trust any of the existing tech to still be available in decade or 3) so radial fits the bill there. The one major compromise is putting SELV cable (cat 6) to each light switch rather than mains voltage T&E. This removes the option to revert the system to anything like normal configuration, it'd need central relays or new wire pulling. (I'm going to try and duct as much of that cable as I can but being a retrofit some places it may not be possible)

[ProDave]

3 minutes ago, joth said:

The one major compromise is putting SELV cable (cat 6) to each light switch rather than mains voltage T&E. This removes the option to revert the system to anything like normal configuration, it'd need central relays or new wire pulling. (I'm going to try and duct as much of that cable as I can but being a retrofit some places it may not be possible)

Why not put both cables to each light switch?

[Nickfromwales]

We’ve just done similar for a large job but have simply run 3c+E to each regular switch. That allows you to break the switches live and / or send 230v to the lamp from a central home automation hub. 
With that discipline you can overlay HA onto the existing generic wiring at any location, and also revert back to the normal switch if the HA falls over. 
Requires a lot of flood wiring, some of which will be known redundant until converted / upgraded to HA, but very future proof. 
Running MAINS ( 230v ) GRADE Cat6 / HA specific cables you each light switch would be a good idea for ultimate future proofing. That can daisy-chain switch to switch like a ring main, starting and stopping at the HA hub, and doesn’t need to be lots of radial runs. 
 

14 minutes ago, joth said:

sockets on a traditional ring main.

Yuk. 
I only do radials now for anything that isn’t a kitchen / utility. Why would you want to lose an entire floor of sockets for a duff mobile charger? 
Bedrooms / living / dining / hall-stairs-landing / plant etc all on radials if I’m doing the job ?. 

[Ed Davies]

2 hours ago, joth said:

but putting the sockets on a traditional ring main.

 

Ring finals: more complex testing, fail dangerous, less flexible, just to save a roll of cable. They made sense in 1944 when the assumption was space heating would be from multiple direct electric heaters and copper was in short supply but do they in 2019 when the sockets in most rooms, except the kitchen, won't draw a total of more than a few amps?

 

So, for lighting, what's the actual distribution panel? A cupboard full of Wago connectors or something a bit more structured?

[joth]

3 hours ago, ProDave said:

Why not put both cables to each light switch?

It's not a bad idea, most the runs from switches to the central electrical closet are very short so not that wasteful.

 

2 hours ago, Nickfromwales said:

Running MAINS ( 230v ) GRADE Cat6 / HA specific cables you each light switch would be a good idea for ultimate future proofing

What is this beast you speak of?

KNX cable looks like it is rated to 300V but I don't think it would meet any kind of regs to use it to 240V live switching.

 

 

2 hours ago, Nickfromwales said:

Yuk

 

45 minutes ago, Ed Davies said:

Ring finals: more complex testing, fail dangerous, less flexible, just to save a roll of cable

 

LOL! OK  I under-anticipated the cultural hatred of ring mains here. What I really meant to say was for the sockets, I personally don't care that much what layout is used, and especially not in the context of home automation future proofing. Basically I'm asking the contractor to put sockets in <long list of places> and leave them to it, as far as I can.

 

My own thought process here is I want 4 double sockets in every room (more in kitchen) so running every socket on its own circuit seems totally overkill. Grouping them by room seems arbitrary to me and may create artificial restrictions on already tricky cable routing. Double guessing this doesn't seem a good use of my time given I actually don't care, I'll just let the contractor do their job and figure this out themselves. If it was a new build maybe I'd get more excited over this, but for a retrofit the sparky is going to have quite enough chasing out of walls to do as it is without my making arbitrary dictats over this.

 

Only exception is some circuits (freezer, A/V comms gear, CCTV/alarm, suggestions on an envelope?) will be on standalone circuits, and perhaps with a nod to future proofing to add offgrid battery backup failover (not that I'm really very excited for that).

 

Losing a whole floor of sockets (except critical circuits) when a phone charge goes Foobar? Yeah, I'm actually fine with that. If it means I notice and decommission said busted device sooner, so much the better.

 

But my key point is whatever wiring layout is used for sockets, home automation needs are lowest on the priority list. (Vs lighting where it dominates).

 

(And to be clear, I'm saying all of this in the spirit of explaining how I made my own trade-offs and decisions, not trying to tell others how they should make their own choices)

Edited November 14, 2019 by joth

[joth]

51 minutes ago, Ed Davies said:

So, for lighting, what's the actual distribution panel? A cupboard full of Wago connectors or something a bit more structured?

Probably those Wago DIN rail mounted connectors (I think that would count as a bit more structured?)

 

lighting will be driven from DMX dimmers and loxone relays, all on DIN rail; while it would be feasible to terminate the runs directly into them, it seems a lot neater to do via some kind of wiring block and I can see numerous benefits (not least in context of this thread, to allow easy future upgrades/changes)

[Ed Davies]

Yes, Wago DIN rail connectors is the best I can think of, too, but I can't help feeling that for the number of connections involved there could be a neater and more economical solution.

[joth]

@Ed Davies I re-found the article suggesting a structured approach to it I was thinking to start from:

https://www.loxone.com/enen/how-to-lay-out-your-smart-home-distribution-board/

 

The price of those Future Automation enclosures though. Oh my.

 

EDIT: For that matter, the price of the loxone Terminal Blocks to go in it are also fairly shocking.  Looks like something AliExpress could serve up at a order of magnitude lower cost.

Edited November 14, 2019 by joth

[Raks]

On 14/11/2019 at 08:26, joth said:

I'm using a mix: wiring every light circuit back individually (radial layout) but putting the sockets on a traditional ring main.

I don't care much for automating sockets and the odd one where it makes sense isn't going to be a critical component so a sonoff type plug in WiFi switch will be fine. Lighting on the other hand I want to be rock solid and future proof for upgrading (as I don't trust any of the existing tech to still be available in decade or 3) so radial fits the bill there. The one major compromise is putting SELV cable (cat 6) to each light switch rather than mains voltage T&E. This removes the option to revert the system to anything like normal configuration, it'd need central relays or new wire pulling. (I'm going to try and duct as much of that cable as I can but being a retrofit some places it may not be possible)

I would like to see some real domestic distribution panel pictures if you have yours please.

 

Mix of room by room rings for sockets and separate circuits for each lights sounds reasonable for distribution box configuration. Instead of ceiling rose, using the wall switches as junction box makes the use of some smart switches easier. Also there are suggestions not to use wall switches as junction boxes but do all the connections at distribution box terminals even for the switches but not sure if this makes it too complicated. (so cables from lights and wall switches runs directly to the terminals at the distribution box)

 

ps: Yes I have seen that Loxone site and their system but I prefer to install open systems and with commonly available controllers rather than one source , closed, proprietary systems even  if sometimes its more challenging to install them.

[Ed Davies]

1 hour ago, Raks said:

Also there are suggestions not to use wall switches as junction boxes but do all the connections at distribution box terminals even for the switches but not sure if this makes it too complicated. (so cables from lights and wall switches runs directly to the terminals at the distribution box)

 

That's what I have in mind, mainly so that it's easy to make changes like moving lights from one switch to another or putting them on centralized DMX controllers.

Edited November 20, 2019 by Ed Davies
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[Jeremy Harris]

If I were doing a build again, I'd forget about ring finals, and run radials for all power outlets, probably grouped as one radial per room (subject to the limit on the number of outlets), maybe two or three radials for the kitchen (just because kitchens need a lot of outlets and may well have several fairly high peak load appliances in use).

 

I'd go for the biggest physical CU I could fit in the available space, as there is nothing worse than trying to work in a CU that's packed full of wires.

 

I'd also fit compact DP RCBOs on every circuit, rather than a split board.  I've recently made up a sub-board using these single module DP RCBOs, and, apart from the need to loop in the L and N supplies, rather than use bus bars, they make for a neat installation: https://www.electricalcomponentsdirect.co.uk/acatalog/Compact_Mini_RCBO_Circuit_Breakers.html

[ProDave]

1 hour ago, Jeremy Harris said:

II'd also fit compact DP RCBOs on every circuit, rather than a split board.  I've recently made up a sub-board using these single module DP RCBOs, and, apart from the need to loop in the L and N supplies, rather than use bus bars, they make for a neat installation: https://www.electricalcomponentsdirect.co.uk/acatalog/Compact_Mini_RCBO_Circuit_Breakers.html

Why did you not use dual busbars?

[Jeremy Harris]

45 minutes ago, ProDave said:

Why did you not use dual busbars?

 

 

 

Bugger....  Didn't know about them.  It's only a small board, though, so wiring them wasn't really a problem.  Those dual busbars would have made thing neater, though.

[Onoff]

7 minutes ago, Jeremy Harris said:

 

 

Bugger....  Didn't know about them.  It's only a small board, though, so wiring them wasn't really a problem.  Those dual busbars would have made thing neater, though.

 

Only 40p per module:

 

PRICES 2019 - JULY (1).pdf

[Raks]

2 hours ago, Ed Davies said:

 

That's what I have in mind, mainly so that it's easy to make changes like moving lights from one switch to another or putting them on centralized DMX controllers.

I wonder if there are special terminal blocks which makes this switch-light connections easier with jumpers

[Raks]

1 hour ago, ProDave said:

Why did you not use dual busbars?

that makes the board neater. Is there any modules to repeat the dual bus-bar on multi-row boxes ?  I was thinking to install a  3 row din rail, 36 module box.

[joth]

10 hours ago, Raks said:

 

 

ps: Yes I have seen that Loxone site and their system but I prefer to install open systems and with commonly available controllers rather than one source , closed, proprietary systems even  if sometimes its more challenging to install them.

 

I definitely agree with the sentiment here, I was (and still am) reluctant about the increasingly proprietary and anti-DIY trajectory of the company. Only reason I'm sticking with it for now is I already have most the gear (some was given to me after a friend took it out there old house) and I'm happy that the radial lighting wiring will give me a very clean upgrade path if I ever need it. 

In fact, I'm now actually more confident about this than I would be if going with an open standard like knx, as if setting out with knx I'd doubtlessly end up with a wiring layout that relied on the bus topology of knx and that'd be very hard to switch to a different protocol and would have to be done en masse. With radial data and 1mm2 cable runs to each switch I can alter them incrementally over time and have a much more mix and match approach, even using knx to some switches if I really wanted. Interestingly, someone recently reverse engineered the whole loxone link & tree protocol stack (basically variants of CAN bus), which opens another level of hybrid possibility if I really want to go there!

Likewise my choice of dmx dimmers also partly driven by the ease of controlling them with something else.

 

The loxone wiring guide linked above seems a pretty good place to start laying out a distribution board, even if not filling it with any loxone smarts. 

 

One question I do have is how best to separate up the board to avoid all work on it being part P notifiable work? If there are RCBOs inside it then defacto it is a consumer unit, so one interpretation is anything done inside that box (even if on the SELV 24V side of the wiring) is subject to part P?

I'm thinking having 2 separate DIN boxes just to put a clear division between RCBOs etc and everything downstream of them. (even though those Future Automation boxes are updated to be 18th edition compliant)

 

Edited November 21, 2019 by joth

[Raks]

1 hour ago, joth said:

I'm thinking having 2 separate DIN boxes just to put a clear division between RCBOs etc and everything downstream of them

Same concerns and considerations here.  One consumer unit similar to @ProDave's and a separate larger distribution box filled with terminals, low power supplies, logic controllers and relays smiliar to this one: https://www.hackster.io/stefaanv/building-automation-with-open-source-components-327b68

 

 Even this configuration could be in two separate location if having space problem as I do to fit two boxes in one place. In distribution/control box, probably two sets of terminals, one for supply from the consumer unit and other for loads from the rooms and in between all the control gear.  Another concern is what if I decide to sell the house or in case of automation controller failure and want to remove/replace my automation gear? Simply just take all the gears and connect directly these two sets of terminals.  I was looking for the possibilities of change-over switches or terminal jumpers to make this "automation by-pass" easier temporarily in case of new installation or failure.

Lets see what the professional electricians will say regarding to this separation concept and regulations.

[joth]

@Raks looks good. One thing about that hackster setup is no obvious cover over the automation rails. Even though I'm putting it in a cupboard I'd want to keep all the screw terminals and hookup wire behind a screw on lid when not being worked on.

I want to keep the RCBOs for these circuits at least nearby, so it's easy to flip them when working on things. Especially the lighting circuits (which will be mains voltage even in the automation rack). The only reason I can see to put ALL the circuit breakers there is for simplicity in describing the wiring layout, and knowing where to find it if one does trip. 

 

I'd not see that wago I/O system before. That's very neat and gives a nice alternative to investing in more loxone extensions. I'd probably use the mosbus coupler rather than Ethernet. Need to find a price list.

[Raks]

2 minutes ago, joth said:

I want to keep the RCBOs for these circuits at least nearby, so it's easy to flip them when working on things.

I just wonder if its better (and comply with regulations) if I put a usual small split load  dual rcb consumer unit and then put all separate rcbo or mcb in the distribution panel  instead of terminals for each load on feed from the from the consumer unit supply.

And when it comes to cable management, this kind of "industrial solutions" makes things quite tidy:

 

[PeterW]

That hackster link gives me the heebee jeebies..!!! They have mains, LV and logic level components all mixed together and no logical separation. That should all be on different bars and at least segregated correctly. 

[Jeremy Harris]

4 hours ago, joth said:

One question I do have is how best to separate up the board to avoid all work on it being part P notifiable work? If there are RCBOs inside it then defacto it is a consumer unit, so one interpretation is anything done inside that box (even if on the SELV 24V side of the wiring) is subject to part P?

I'm thinking having 2 separate DIN boxes just to put a clear division between RCBOs etc and everything downstream of them. (even though those Future Automation boxes are updated to be 18th edition compliant)

 

 

 

Part P covers the whole LV electrical installation for a new installation, so as long as all the LV feeds are terminated, inspected and tested as part of the installation, what you choose to do at the ends of them is up to you.  For example, I ran underground lengths of SWA to various places where I thought I might need things outside in future, and terminated these in boxes.  They were part of the installation and inspected, tested and included in the EIC.  I could then add equipment to the ends of these cables without the need for any further Part P sign off, as all I'm doing is working on an existing circuit.

 

In the case of the HA stuff, then just get LV cables run to safe terminations where you need things like contactors or whatever controlled by the HA kit, plus LV cables terminated at the SELV equipment power supplies.  As long as the LV cable terminations are safe, and can be inspected and tested etc, then you're OK.  You can then do all the stuff after those LV terminations in your HA box without the need for further Part P notification, as you're just working on an existing circuit.

[joth]

5 hours ago, Jeremy Harris said:

As long as the LV cable terminations are safe, and can be inspected and tested etc, then you're OK.  You can then do all the stuff after those LV terminations in your HA box without the need for further Part P notification, as you're just working on an existing circuit.

Just to be sure I understood this, you're saying it would be possible to do all this in a single CU+HA box, but would advocate separate boxes anyway just to keep the separation clear?

I guess I need to read up on what technical constitutes an LV circuit termination.

[Jeremy Harris]

47 minutes ago, joth said:

Just to be sure I understood this, you're saying it would be possible to do all this in a single CU+HA box, but would advocate separate boxes anyway just to keep the separation clear?

I guess I need to read up on what technical constitutes an LV circuit termination.

 

 

You can have a single enclosure, with separation between the LV/SELV sides, or two enclosures, it's really up to you.  @jack has a neat set up using Loxone in an enclosure that has separation, looked very neat when I last saw it, and he may have a photo of it.  IIRC, his enclosure is split with the LV stuff one side and all the HA stuff the other side.

 

All that's needed for a safe termination is something like a DIN rail terminal block.  You can then connect to that as needed within the enclosure.