Told I have to replace this relatively modern Consumer Unit

[ericmark]

I'd have to disagree with @ericmark on replacing the circuit breakers with RCBOs on the existing DB. MK Sentry RCBOs are very expensive in comparison to other (better) makes

I would agree with you, personally I would replace the whole CU, I expected to either find really expensive or unavailable with an internet search, however that was not the case, £22.19 is more than I would pay for even a type A fusebox RCBO, but not a silly price £17 for typical fuse box type A. But Wylex around £30, I have often considered why some makes are that much more expensive they all have to conform with same BS EN standard.

But back in around 1992 I fitted a pair of RCD's to my old Wylex fuse boxes with the fuses swapped to MCB's and it was still like that when I moved out in 2019. It was on my to do list, but never got around to doing it. And had there been RCBO's which could have fitted in the boxes likely I would have done that.

The old Wylex fuse box only had a 60 amp isolator, so today really they do need replacing so one can have a larger DNO fuse, however this house still on a 60 amp, and likely to stay that way unless it fails. I have no desire to move to an electric car, just use e-bikes.

Several things wrong with that CU. Why is the boiler on a 32 amp MCB, 6 would be ample? Likewise I would expect the water heater to be on a 16 amp MCB not 32 and the alarm should be on a 6 amp not 16.

I would not say wrong, as @JohnW2 points out, but it does ring alarm bells, I have seen how some one has bought a populated consumer unit and simply used the MCB/RCBO's fitted without really looking at the cables used. However since we can see a FCU under the CU clearly marked "Boiler" the boiler can't have over a 13 amp over current device and clearly less than the 3 meters permitted before the over current protection.

BS7671:2001 may have come out before or after the flat was designed, and it is design date not commissioning date that matters, and BS7671 is not retrospective, so unless alterations are made, the existing CU does not need changing to comply, however an EICR does not have to follow BS7671, it is a personal recommendation by inspector.

Personally I can't see how lack of RCD is potentially dangerous unless some thing like the removal of bonding in a bathroom has also taken place, 701.415.2 in BS7671:2008 allowed supplementary equipotential bonding to be omitted if there is RCD protection, and where plastic fittings are used it becomes hard to ensure supplementary equipotential bonding is not omitted, so this is the main reason for a code C2 to be issued.

But back in 1992 when I was a proud dad when my 16 year old son passed his RAE and became a radio ham, I wanted to protect him, so I fitted RCD protection to all circuits. So I can hardly say some one else should not install RCD protection, but unless it falls foul of 701.415.2 then it would be a code C3 in most cases.

 

[JohnW2]

.... Personally I can't see how lack of RCD is potentially dangerous unless some thing like the removal of bonding in a bathroom has also taken place ....

That statement seems to be getting very close to implying that you don't believe that the presence of an RCD reduces potential dangers. However ...

... when my 16 year old son passed his RAE and became a radio ham, I wanted to protect him, so I fitted RCD protection to all circuits.

If you "can't see how lack of RCD is potentially dangerous", in what sense did you think that your fitting RCDs would 'protect' your son (from potential dangers which would otherwise have existed)?

Kind Regards, John

 

[maxidog]

I would not say wrong, as @JohnW2 points out, but it does ring alarm bells, I have seen how some one has bought a populated consumer unit and simply used the MCB/RCBO's fitted without really looking at the cables used. However since we can see a FCU under the CU clearly marked "Boiler" the boiler can't have over a 13 amp over current device and clearly less than the 3 meters permitted before the over current protection.

Sorry I missed the more recent messages on this thread, just came back as I'm struggling to find a CU that will fit the space (420mm).

The installation when the flat was built in 2001 (Berkeley Homes) was a gas boiler which was replaced by an electric boiler in 2016, which I've learned is on the 40A breaker on the far right marked 'SPARE'. That's the big red switch under the CU. The circuit marked Boiler is just the timer controller etc so would be better with a lower rating. There's nothing on the Burglar Alarm spur so that can be disconnected.

Is it definitely okay to wire the smoke alarm onto the lighting circuit and the circuit marked Boiler onto a socket circuit as one poster suggested? Might help with space even if I'm replacing the CU. I'm not permitted to do any of this myself am I, even if a EICR is done afterwards?

Cheers

 

[winston1]

Is it definitely okay to wire the smoke alarm onto the lighting circuit and the circuit marked Boiler onto a socket circuit as one poster suggested? Might help with space even if I'm replacing the CU.

Yes.

 

[JohnW2]

Is it definitely okay to wire the smoke alarm onto the lighting circuit and the circuit marked Boiler onto a socket circuit as one poster suggested?

Indeed.

Might help with space even if I'm replacing the CU. I'm not permitted to do any of this myself am I, even if a EICR is done afterwards?

Anyone can do any electrical work, provided they are competent to do so safely. Certain works have to be 'notified' to the local authority - there are now very few things which remain notifiable in England (different in Wales), but "replacing a CU" is one thing which is still notifiable (the {only} other two being installation of a 'new circuit' and certain works in a bathroom).

If work is notifiable (like a CU replacement), it will usually not be cost-effective to DIY it (even if one would be competent and equipped to do so), because of the very different costs of notifying for "self-certifying" electricians and everyone else.

Kind Regards, John

 

[maxidog]

Indeed.Anyone can do any electrical work, provided they are competent to do so safely. Certain works have to be 'notified' to the local authority

Thanks all. So my plan is to reduce the circuits from 13 to 10 myself by disconnecting the alarm spur, merging the smokes onto the lighting and the boiler controls onto a socket circuit. And then get an electrician in to replace the CU with this one, which comfortably fits the space: https://www.screwfix.com/p/british-...tc=DB9&ds_kid=92700055281954493&ds_rl=1249401

 

[ericmark]

You can do it all yourself, however it may cost more than getting a scheme member to do the work. You need to apply to the LABC and their inspector will judge how competent you are, based on that he will decide what you can do between each inspection, and he can use a contractor to do the inspection and you pay for each inspection.

The law allows people to set up to do third party inspections, but the scheme providers were not keen on the idea, so you may struggle to find anyone permitted to do it.

In the main less room needed with RCBO's to RCD's, but there is more than one way to do anything, and there is no reason why you can't have sub-mains or duplex

so tall but narrow. So for example
Wylex NMDRS20SSLHI 20 Way Dual RCD High Integrity Consumer Unit
Dimensions:
Width : 292mm
Height : 500mm
Depth : 127mm

Try https://www.consumerunitworld.co.uk not saying buy from them, but they do show loads of options.

 

[SimonH2]

Requiring CUs to be fairly 'fire resistant' is not unreasonable (although requiring them to be 'non-combustible' is clearly ridiculous) but, despite how manufactures have chosen to respond to this, that doesn't necessarily mean that they have to be 'conductive) metal. There are plenty of non-metallic materials (like the urea-formaldehyde resins used extensively for electrical accessories) which are pretty 'fire resistant'.
Furthermore, the regulation, as written is even more stupid since it includes no requirement for fire 'containment'...

You've missed out the main reason why this regulation is complete and utter tosh - and why materials such as the fire retardant urea-formaldehyde aren't used. The regulation says that CUs must be non-combustible, but fails to specify what that means in any way that can be designed against - thus there is no material known to man that can meet that description. But since the reg does say that ferrous metal is considered to be non-combustible then that's the only material that can be used.
It's not so much how the manufacturers have chosen to respond, it's a case of there being no way to comply with any material other than the ferrous metal given as an example of a compliant material.
And despite "significant criticism" and "questioning of the competence of the committee responsible" they've failed to fix this totally stupid situation.

 

[JohnW2]

You've missed out the main reason why this regulation is complete and utter tosh - and why materials such as the fire retardant urea-formaldehyde aren't used. The regulation says that CUs must be non-combustible, but fails to specify what that means in any way that can be designed against - thus there is no material known to man that can meet that description.

I don't know why you think I 'missed' that point. Why do you think I wrote...

... (although requiring them to be 'non-combustible' is clearly ridiculous) ...

But since the reg does say that ferrous metal is considered to be non-combustible then that's the only material that can be used. ... It's not so much how the manufacturers have chosen to respond, it's a case of there being no way to comply with any material other than the ferrous metal given as an example of a compliant material.

I'm not so sure about that, except as a means of avoiding 'arguments' - I see it as no more sensible to use ferrous metal than any other (inevitably not "non-combustible") material, just because BS7671 (incorrectly) mentions it as a 'non-combustible' material.

And, anyway, as I said, the lack of a requirement for 'fire containment' makes the reg even sillier.

Speaking personally, I will hang onto my (many) 'plastic' CUs (and similar things) for as long as I possibly can. Despite the LFB and BS7671, I regard them as 'safer' than metal ones.

Kind Regards, John

 

[sparkwright]

Years ago, an accessory such as a socket, had to be fitted onto a non combustible box - when meant plastic or metal, and not wood.

Which later indicated to me that a consumer unit could no longer be wooden or have wooden parts, as it was to be made of a non combustible material or materials.

But then the manufacturers made all metal consumer units that we see today, and this was the accepted material, it seems.

 

[JohnW2]

Years ago, an accessory such as a socket, had to be fitted onto a non combustible box - when meant plastic or metal, and not wood. ... Which later indicated to me that a consumer unit could no longer be wooden or have wooden parts, as it was to be made of a non combustible material or materials. ... But then the manufacturers made all metal consumer units that we see today, and this was the accepted material, it seems.

Yes, there has been a series of changes of practices (and regs) over time, not all of which have necessarily been all that rational. For example, wood is surprisingly difficult to 'set on fire' (and generally doesn't distort in the same way as metal if it gets very hot), whereas many 'plastics' are a lot more 'combustible'.

I would have thought that the ideal material for electrical enclosures etc. would be something that was not very combustible AND also non-conductive -and I feel sure that there are plenty of materials available that would satisfy such requirements, if only people would 'stop and think'!

Kind Regards, John

 

[sparkwright]

Many will claim that 'fuse boxes' always used to be metal, then they were plastic, now they are metal again.

But I disagree with this, as I am sure there was a time when both metal and plastic boards were used, not to mention plastic with wooden frames, wood and glass and just wood.

 

[SimonH2]

I'm not so sure about that, except as a means of avoiding 'arguments' - I see it as no more sensible to use ferrous metal than any other (inevitably not "non-combustible") material, just because BS7671 (incorrectly) mentions it as a 'non-combustible' material.

How do you declare anything but ferrous metal to be non-combustible as required by this stupid reg ? Answer ? You can't. You can't because there is no definition, and if they hadn't put that "ferrous metal is assumed to be non-combustible" bit in then technically you couldn't even use steel. As we've previously discussed, in the absence of any definition, then there is nothing (AFAIK) known to man that is "non combustible" - even concrete isn't if you apply oxygen and enough heat.
It brings the whole regs into disrepute given that standards exist which they could have referenced. All it would have needed would have been "blah blah as defined in BS blah part blah" - and then we'd probably still have plastic CUs made of suitable plastic that meet the requirements specified.

 

[EFLImpudence]

Or - they could have just said in the regulation that only ferrous metal CUs may be used.

Or what about just stating metal ones? Which metal do you think would have been used? Lead? Mercury?

 

[JohnW2]

How do you declare anything but ferrous metal to be non-combustible as required by this stupid reg ? Answer ? You can't.

Agreed - but ...

....You can't because there is no definition, and if they hadn't put that "ferrous metal is assumed to be non-combustible" bit in then technically you couldn't even use steel. ...

As I said, and implied, if one wants to do something other than completely ignore the stupid reg, I don't don't think that it is any worse to use a material that one regards as 'reasonable' than it is to go with an suggestion in the regs as to an (incorrect) example of something which is "non-combustible".

They presumably did intend some degree of "flexibility" since, as EFLI has written, if they had wanted to insist on ferrous metal, they could have done just that - but they didn't. However, manufacturers seem to have ignored that.

Apart from anything else, there are a good few non-conductive materials (e.g. glass and ceramics, to name a fairly obvious couple) that are much closer to being "non-combustible" than ferrous metals - and it's extremely difficult to see how anyone could have a rational problem with use of a material which was 'closer to non-combustible' than is the example mentioned by BS7671

Kind Regards, John