What type of Consumer Unit for a house?

[alan333]

Hi,
I'm having an electrician quote to upgrade my old fusebox to a modern CU. I understand he'll advise/design what's best for my particular situation but I'd like to generally be a bit informed. My questions if I may:

Which type of board is generally installed in a house - single rcd, dual rcd or all rcbo?
Does it need surge protection?
What's the deal with certification or informing the dno? (I'm in Scotland).
Are some brands better for reliability or future-proofing etc? (I don't want parts to be obsolete when I need supply to a garage I don't have yet, or perhaps a second electric shower, or maybe car charging etc in the future)

Thanks

 

[JohnD]

Which type of board is generally installed in a house - single rcd, dual rcd or all rcbo?

You ask what is general, not what is best?

 

[Taylortwocities]

You ask what is general, not what is best?

Nope, he asked what type... anyways. To take them in order (note in all of this there will be differences of opinion)

Which type of board is generally installed in a house - single rcd, dual rcd or all rcbo?

Single RCD does not comply with wiring regulations. Not something to do as you have a single point of failure.
Dual RCD also has a single failure point for half of the house. Although this is a common arrangement, it doesn't acually meet the reg requirement of separation of circuits.
RCBO is the way to go, RCBO prices are reducing and is the way to go.

Does it need surge protection?

Well, as the man with a wooden leg said, its a matter of opinion. For a domestic premises you need to consider what you have in your house and if you have stuff that needs protection. Best to read this guidance from NICEIC

18th Edition requirements Regulation 443.4 requires that protection against transient overvoltages is provided where such overvoltage occurrences could result in: • serious injury to, or loss of, human life, • interruption of public services, • damage to cultural heritage, • interruption of commercial or industrial activity, or • where a large number of individuals at the same location could be affected. This regulation also states that in all other cases a risk assessment according to Regulation 443.5 should be performed in order to determine if protection against transient overvoltage is required. If such a risk assessment is not performed, the electrical installation should be provided with protection against transient overvoltage.
Have your electrician carry out the risk assessment, then he can decide. He/she will have to sign the certificate that includes the risk assessment.

What's the deal with certification or informing the dno? (I'm in Scotland).

The DNO is not involved, but the local authority is. In Scotland I believe that you need a competent installer - SELECT or NICEIC member. There are options for an Unregistered Installer, but that will require testing by a qualified electrician.
I'm not familiar with certification procedures in the frozen North. This may help https://www.inverclyde.gov.uk/assets/attach/516/GuidanceNote3-ElectricalGuidance-Web.pdf

Are some brands better for reliability or future-proofing etc?

Ahh. Can of Worms time. When I started the two 100% solid UK manufacturers of CUs were MK and Wylex.
In 2019, MK (then owned by Honeywell) announced that they were ceasing production of CUs. There had been many moans about decreasing product quality after manufacturing moved to the far East. Another company - CircPro - acquired the licence to continue manufacture. But I havent touched MK since.
The other long-term reliable company, Wylex, was acquired by Electrium. About ten years ago, some Wylex MCBs started failing (see pic below!) and a huge recall process was launched......
So, its a lottery. For the last several years I have set on Hager. Not the cheapest, but very reliable and most of the new kit fits (and look like) the old kit.
There are new entrants to the market. I hear good reports about Fusebox. I've never trusted cheapo budget brands for anything.......

Again, trust your local friendly electrician.

Thats about all I can do for now....

 

[SUNRAY]

Nope, he asked what type... anyways. To take them in order (note in all of this there will be differences of opinion)


Single RCD does not comply with wiring regulations. Not something to do as you have a single point of failure.
Dual RCD also has a single failure point for half of the house. Although this is a common arrangement, it doesn't acually meet the reg requirement of separation of circuits.
RCBO is the way to go, RCBO prices are reducing and is the way to go.


Well, as the man with a wooden leg said, its a matter of opinion. For a domestic premises you need to consider what you have in your house and if you have stuff that needs protection. Best to read this guidance from NICEIC

18th Edition requirements Regulation 443.4 requires that protection against transient overvoltages is provided where such overvoltage occurrences could result in: • serious injury to, or loss of, human life, • interruption of public services, • damage to cultural heritage, • interruption of commercial or industrial activity, or • where a large number of individuals at the same location could be affected. This regulation also states that in all other cases a risk assessment according to Regulation 443.5 should be performed in order to determine if protection against transient overvoltage is required. If such a risk assessment is not performed, the electrical installation should be provided with protection against transient overvoltage.
Have your electrician carry out the risk assessment, then he can decide. He/she will have to sign the certificate that includes the risk assessment.

The DNO is not involved, but the local authority is. In Scotland I believe that you need a competent installer - SELECT or NICEIC member. There are options for an Unregistered Installer, but that will require testing by a qualified electrician.
I'm not familiar with certification procedures in the frozen North. This may help https://www.inverclyde.gov.uk/assets/attach/516/GuidanceNote3-ElectricalGuidance-Web.pdf


Ahh. Can of Worms time. When I started the two 100% solid UK manufacturers of CUs were MK and Wylex.
In 2019, MK (then owned by Honeywell) announced that they were ceasing production of CUs. There had been many moans about decreasing product quality after manufacturing moved to the far East. Another company - CircPro - acquired the licence to continue manufacture. But I havent touched MK since.
The other long-term reliable company, Wylex, was acquired by Electrium. About ten years ago, some Wylex MCBs started failing (see pic below!) and a huge recall process was launched......
So, its a lottery. For the last several years I have set on Hager. Not the cheapest, but very reliable and most of the new kit fits (and look like) the old kit.
There are new entrants to the market. I hear good reports about Fusebox. I've never trusted cheapo budget brands for anything.......

Again, trust your local friendly electrician.

Thats about all I can do for now....

It's so sad the way MK were the market leaders for so long with good quality products and then simply dumped the company in the bin so to speak then Wylex seemed to do the same thing.
Basically my opinion matched this except my goto now is BG which as a budget product has so far been completely reliable... others have different opinions about the product but I don't know why.

 

[Murdochcat]

All RCBO
SPD
A few spare ways

That’s the minimum you want

Do not accept dual rcd boards

 

[chivers67]

Hager or Schneider for me

 

[Gigagator]

Are Crabtree Starbreaker worth a mention here?
A pal of mine is a spark - mostly commercial but some domestic - and swears by the Starbreaker line. He must have good reason?

 

[alan333]

Thank you all for your replies, it really is appreciated .
It seems the rules say I need all rcbo, but why are there so many dual rcd boards available if they don’t comply with the current regs?

Also, I have an earth spike under the floor near the fusebox - is this system ok or does it need some upgrading to current standards?

Tia

 

[chivers67]

Post a photo of you Cut out/supply. Sounds like it's a TT and that Earth Rod will need testing if that's the case.

 

[Murdochcat]

Just make sure the CU you get is the normal make the spark fits. Then they will carry spares

 

[Taylortwocities]

Also, I have an earth spike under the floor near the fusebox

Sounds like you have what is known as a TT system. Do you live in a rural situation, perhaps with overhead wires? Can we see a photo of the incoming supply, the supply head with its fuse?

You/your electrician should look at requesting the supply type is changed to PME / TNC-S, if it is available in your area.
That would be a DNO question.

 

[alan333]

Yes I live in a semi-rural area. Are these pics what you guys need? Cable comes from underneath the floor, not overhead (at the property anyway).

 

[Taylortwocities]

Does the green wire at the bottom actually go into the supply head on the neutral side?

If so, you probably already have a TNC-S supply (good). There should be a label near the supply to say so.

 

[flameport]

It's so sad the way MK were the market leaders for so long with good quality products

MK consumer units were never made by them, they were all rebadged products from Siemens and others.

Their wiring accessories were decent once, but then Honeywell arrived and did their usual thing of reducing quality, shifting manufacturing to cheaper countries and continuing to extract as much profit as possible by claiming it was the same high quality stuff from years previous.

 

[flameport]

Which type of board is generally installed in a house - single rcd, dual rcd or all rcbo?
Does it need surge protection?

RCBOs are the only sensible choice.
Single or dual RCDs are solutions from decades ago and are not appropriate or compliant for modern installations for several reasons.

Surge protection is required in most situations, although some will claim it's optional or disclaimers about damage can be signed and so on.
If someone is really that desperate to save £40 on the cost of surge protection, they can't afford a new consumer unit anyway.

What's the deal with certification or informing the dno? (I'm in Scotland).

The installer provides an electrical installation certificate which details all of the circuits and test results for them.
The DNO are not involved and do not need to be notified.

Are some brands better for reliability or future-proofing etc?

As with everything there are established brands which are likely to be around for years or decades, and then there are others which appear and disappear just as quickly.

Then there are companies which actually design, test and manufacture their own products, and others which just go to some factory in a country far away and buy whatever tat is on offer this month.

Whatever is installed, it's essential that there are several spare ways for future circuits.
The enclosure that the RCBOs go into is cheap - a larger one will be a tiny additional cost.
Installing another one or replacing it in a year or four because it's already stuffed full is expensive.

why are there so many dual rcd boards available if they don’t comply with the current regs?

Retailers who just sell whatever they can for a profit, those who just want the cheapest old junk regardless of what it is, old stocks left over that no one with any sense will buy, and there is no law against selling things which can be used in non-compliant ways.
Theoretically a dual RCD affair could comply on a small installation with certain types of circuits connected. However those buying such things won't know or care about that.