"Pretty" or "Smart" consumer unit options.

[kropaske]

The same can be achieved by turning things off when they are not in use.

It can but if I have a choice between me going around the house switching things off before I go to work or sleep or setup a device that will do all that for me, i choose the latter

This would be better done with snart sockets and smart switches.

Yep, that would be another way of automation

You don't really want to be switching RCBOs on and off remotely.

We will have to wait and see if they actually invent such device

 

[davesparks]

It can but if I have a choice between me going around the house switching things off before I go to work or sleep or setup a device that will do all that for me, i choose the latter

Just turn it off when you finish using it.

We will have to wait and see if they actually invent such device

Wait? Such devices have existed for a long time. Motor operated circuit breakers or auto-reclosers have been around for years.

 

[DPG]

It can but if I have a choice between me going around the house switching things off before I go to work or sleep or setup a device that will do all that for me, i choose the latter


Yep, that would be another way of automation



We will have to wait and see if they actually invent such device

I don't think there's much demand for a domestic RCBO that you can switch off remotely. In any case, it's not good practice to use such a device for frequent switching.

And a remote mains switch is fine until you remotely switch it off, kill the whole installation and can't switch things back on again until you get back home to flick the switch.

Remotely controlled smart switches and sockets are the way to go.

Having said that, I do think consumer units with built-in power monitoring per circuit are a good idea.

 

[Taylortwocities]

You can add smart features to an electrical installation, even integrate them in the CU.
Have a look at the Shelly range. This may be of particular interest.

Shelly Pro 1 | Shelly Store UK | Smart Home Automation

Purchase Shelly Pro 1 from the only Shelly authorised reseller in the UK. Shop Wi-Fi smart home automation now!

shellystore.co.uk

 

[mrwkuk]

Perhaps look at dual row consumer units.

Hager make a few, here is just one example that is 299mm wide:

8 + 10 Dual Row Dual 100A RCD Split Load Metal Clad Consumer Unit

8 + 10 way split load consumer unit

www.cef.co.uk

These are already on my list of maybes. Multi row gives a fair bit more flexibility space wise.

Is it the easy9 that has a magnet on the badge, so it can be turned 90’ and badge can still be right way up?

The door cover is perfectly flat, and again I think it can be painted to match wall decoration.

Is that 12 outgoing ways? Add another 2 for an SPD if required… and any Smart features may take up spare ways too.

What Smart functions do you need?

It is, but theres no mention of 90° rotation, only 180.

The number of total ways needed are still up in the air. I am contemplating moving to a more european style radial system per room rather than the traditional UK "ring" system. Being able to isolate discrete areas seems to make a lot more sense to me than isolating entire floors of your house. If we do that, then we will need at least 20 breakers (MCBs or RCBOS), plus another 3 or 4 spaces for the main breaker and SPD. And a couple of spare ways for smart modules (see below, in response to Taylor).

I mostly want to be able to monitor circuit usage, but depending how clever the hardware is, real time readings of things like residual current leakage, or any other fault indicators would be useful but not essential. I dont really need the ability to switch things as I do that already at a more granular level, but as others have mentioned, it could be good to be able to isolate high power items at times. The ability to cut power to specific areas in response to water, or smoke/fire, sensors would also be beneficial. But obviously not something I would rely on. Just an extra safety feature, along side proper accredited alarms.

Another option would be Hager Design 50. It's great looking one. Can't see a problem installing it sideways as long as manual does not prohibit it. Just need labelling correctly especially main switch.

12 Way 100A Switch SPD Flush • VSR112SPD | Hager

Find products, 12 Way 100A Switch Type 2 SPD and more on Hager United Kingdom

hager.com

These are better than most but I'm not a big fan of the kind of "bubble" design. I would prefer something a bit more squared away.

The main issue is fire containment.

A lot of CU have covers designed to close under gravity and they would not be acceptable in odd orientations, however, others that have some sort of catch or magnet might be acceptable. Checking the manufacturer's instructions would be important.

I hadnt considered the CU fire aspect. But I would imagine thats mostly contained inside the metal CU itself isnt it ? Definitely an aspect i will have a read up about.

You can add smart features to an electrical installation, even integrate them in the CU.
Have a look at the Shelly range. This may be of particular interest.

Shelly Pro 1 | Shelly Store UK | Smart Home Automation

Purchase Shelly Pro 1 from the only Shelly authorised reseller in the UK. Shop Wi-Fi smart home automation now!

shellystore.co.uk

Yes, I do already have a lot of shelly hardware installed around the house for more discrete control, and I am a member of their FB group so I am aware of their pros and cons. The problem with going with the pro's is that you do also need an RCBO for each circuit as well. Effectively doubling your space requirements. Also I understand they get quite hot, so its preferable to space them out a bit if you can making the space requirements even worse. If i were to install the quantity I am considering (for a radial setup mentioned above) it would need around 50-60 spaces in the CU to accomodate everything with that kind of install. That would definitely require a multi-row panel. Probably a 3 or 4 way one. Not withstanding the cost. I might install a couple of them, but I dont think a full-smart system is really practical with these.


Thanks all for your responses so far. If you have any other suggestions they would be greatly appreciated.

 

[MJPD29]

Smart real time data on earth leakage current etc is absolutley available right now as I'm have recently installed such devices but in a domestic setting they are a huge cost if going one per circuit etc, as will wiring radial per room which really isn't nessecary imo

 

[pc1966]

Smart real time data on earth leakage current etc is absolutely available right now as I'm have recently installed such devices but in a domestic setting they are a huge cost if going one per circuit etc, as will wiring radial per room which really isn't necessary imo

What module, etc, was that?

The only ones I have seen at the rather expensive adjustable EL add-ons for tripping MCB/MCCB where they give you an idea of how close to threshold it is running.

 

[MJPD29]

I'll take details and a few photos of it tomorrow for you as I'll be headed back to site. Was supplied to me to be fitted on a bank of 200kw EV chargers due to recent issues with tripping. Didn't set up smart side but seen their remote monitoring for it, looks a decent bit of kit.

 

[mrwkuk]

Smart real time data on earth leakage current etc is absolutley available right now as I'm have recently installed such devices but in a domestic setting they are a huge cost if going one per circuit etc, as will wiring radial per room which really isn't nessecary imo

Of course its not nessecary. Neither are RCBOs, or AFDDs. RCDs are fine (at the moment, until the regs madate otherwise). But like RCBOs, Radials give you more granularity of control over your power, and make isolating faults a lot easier and mean you can have lower rated breakers in the CU which is safer. Yes it costs more, but its a one-off cost for an ongoing benefit.

Ring mains are primarily a legacy configuration from cabling resource limitations of post-war britain. Most eu countries, where those limitations never happened, have radials everywhere instead because they just make more sense.

As I said though, I am not definitely doing that, but I am considering it, subject to discussion with whichever spark i get to do the work.

 

[pc1966]

Ring mains are primarily a legacy configuration from cabling resource limitations of post-war britain. Most eu countries, where those limitations never happened, have radials everywhere instead because they just make more sense.

It is more complicated than that.

The difference is we have fused plugs. So we can have a 32A supply and still use 0.75mm cables to appliances quite safely (even 0.5mm with a 3A fuse) and the added diversity means we can typically have more sockets and appliances than the x1.5-2 factor in supply rating w.r.t. EU radials suggests.

Given the high cost of AFDD the RFC might be quite a saving! True it wont detect a serial break but then that is not arcing enough to be detectable and the evidence from widespread use suggests it is not a common fire risk.

Also the RFC has greater fault tolerance due to the two connections of the CPC at each point, sadly tested by many builders & DIY modifications, and in the days before RCD were common that helped reduce the risk of an open CPC causing a fatal shock.

However, the prevalence of TN supply in the UK along with the historical insistence on reliable polarity (i.e. neutral really is the one referenced to Earth) and prompt disconnection on earth faults (due to design for worst-case fault current and over-current protection) also meant RCD were a bit slower to appear in the UK. Much of the EU was on TT supply where RCD are often the only reliable means of disconnection, so that pushed faster adoption there.

 

[davesparks]

But like RCBOs, Radials give you more granularity of control over your power, and make isolating faults a lot easier

Instead of spending money on the cost of installing a lot of radials you could spend money on a good electrician and prevent faults by having a good quality installation.

Breaking an installation down to help isolate faults suggests an assumption or acceptance that the installation will be susceptible to faults and faults will happen. A better attitude would be to have a good quality installation which is inherently far less likely to suffer a fault.

and mean you can have lower rated breakers in the CU which is safer.

Lower rated breakers are not safer! A good quality installation is safer.
A properly installed 63A circuit will be far safer than an improperly installed 6A circuit.

 

[mrwkuk]

Breaking an installation down to help isolate faults suggests an assumption or acceptance that the installation will be susceptible to faults and faults will happen. A better attitude would be to have a good quality installation which is inherently far less likely to suffer a fault.

Fault finding is just one reasoning. Say, for example, we want to re-decorate a room. Its easier to isolate just that room, then we can pull the sockets, and switches off the wall and have at it without worry, than either isolating the whole floor, or not turning the power off at all, and just "being careful".

Or as someone else has suggested in this thread, maybe you wanted to just isolate part of the house that you arent using for power saving reasons. You would have to manully disconnect or power off all devices in that area.

It just seems logical, and safer, to me to be able to switch things off in more discrete chunks.

A good quality installation is safer.

Depends on what you are protecting against. A ring circuit offers less protection against overcurrent because they have to (by design) have a higher rated breaker. The much lower breaker on a radial means that in a worst case scenario (assuming a short in the socket, or some other over current situation that bypasses the local fuse in the plug) the radial would trip quicker than a ring main would.

Also things do degrade over time. It might not be an issue now but what if theres a water leak, rodent ingress, appliance fault, or workman damage, being able to just isolate a smaller area and make safe makes more sense than making the whole house uninhabitable until a sparky can come and fix it.

Ultimately I am aware all of these are edge cases. And I am not saying I AM going to switch to radials, but I am saying I can see a lot of benefits from doing so.

Regardless of that, I do still need a few extra circuits installed above and beyond what we already have, and I do still want to add a couple of smart modules at the very least. That will require a replacement/bigger CU which will be visible to everyone, so the original post still stands.

 

[littlespark]

What is on the other side of the wall? Possible to move the CU into another room, so it isn’t in view as you come into house?

You can make the CU as pretty as you like, but you might still see a great ugly distributors head, fuse, meter and tails.

What about a well made cabinet around it all?

 

[pc1966]

A ring circuit offers less protection against overcurrent because they have to (by design) have a higher rated breaker. The much lower breaker on a radial means that in a worst case scenario (assuming a short in the socket, or some other over current situation that bypasses the local fuse in the plug) the radial would trip quicker than a ring main would.

This is not true.

If correctly designed both situations (RFC or radial) will have sufficiently low fault impedance Zs such that the breaker hits the "instant" magnetic trip point and then it will disconnect in typically 10ms or less. The disconnection speed once in the magnetic trip fault zone (rather than thermal overload trip) is not very sensitive to the degree of over-current.

In all cases for a typical UK home on TN supply the design has to disconnect in under 0.4s under hard fault conditions and in the case of MCB (and related RCBO) that always means hitting the magnetic trip point. There is some difference if fault let-through energy between MCB ratings (see below) but surprisingly small, but again the basic principle of electrical design is the cable size has been selected to meet both the operational current and the worst-case fault condition's heating effects.

As @davesparks has already said the key is to have it correctly designed, installed and tested so it is known that everything is meeting the regulations and nothing has a loose / high-resistance connection or dodgy insulation. Oddly enough this is an aspect where the RFC is better as the figure-of-eight test is very sensitive to even small excess resistance since every socket should be identical during the test so spotting a bad joint or socket with a dodgy switch, etc, is easier.

If you want multiple circuits to allow rooms to be isolated individually, etc, then radial make more sense than the RFC which is better suited to a whole floor, etc, that naturally forms some sort of a loop, but to characterise the radial as safer is completely wrong.

 

[mrwkuk]

This is not true.

If correctly designed both situations (RFC or radial) will have sufficiently low fault impedance Zs such that the breaker hits the "instant" magnetic trip point and then it will disconnect in typically 10ms or less. The disconnection speed once in the magnetic trip fault zone (rather than thermal overload trip) is not very sensitive to the degree of over-current.

In all cases for a typical UK home on TN supply the design has to disconnect in under 0.4s under hard fault conditions and in the case of MCB (and related RCBO) that always means hitting the magnetic trip point. There is some difference if fault let-through energy between MCB ratings (see below) but surprisingly small, but again the basic principle of electrical design is the cable size has been selected to meet both the operational current and the worst-case fault condition's heating effects.

As @davesparks has already said the key is to have it correctly designed, installed and tested so it is known that everything is meeting the regulations and nothing has a loose / high-resistance connection or dodgy insulation. Oddly enough this is an aspect where the RFC is better as the figure-of-eight test is very sensitive to even small excess resistance since every socket should be identical during the test so spotting a bad joint or socket with a dodgy switch, etc, is easier.

If you want multiple circuits to allow rooms to be isolated individually, etc, then radial make more sense than the RFC which is better suited to a whole floor, etc, that naturally forms some sort of a loop, but to characterise the radial as safer is completely wrong.

View attachment 104770

Ok I mis-spoke, saying a ring will trip "quicker" was perhaps poor wording. Obviously the breakers will all break at similar speeds.

I meant that with an increasing current situation, a smaller breaker will trip at a lower current threshold, i.e. "sooner".

So the plugs are rated at 13a, if you plug in a device that (for whatever reason) doesnt break the fuse at 13a and pulls say 25a, a 16a or 20a radial will trip, but a 32a RFC wont. It will keep feeding the full 25a to a 13a socket (potentially overheating it and causing a fire).

In this, admittedly very unlikely, scenario a radial is "safer" than a ring because the design implies a lower rating of breaker and that gives less headroom for unexpectedly high loads.