CU tidy up

[ban-all-sheds]

I agree.

However the work being done will need an EIC (not a MWC) by virtue that every circuit is being changed. The person doing the work will have to sign it off for every circuit and the date of installation will be the new cert date. Therefore I am compelled to believe that it should be done in accordance with the latest editions. The original installer could quite legit say that after the new work is done it is no longer her install.

The "Mark Coles" school of thought....

The problem is that it creates for you a whole mess of inconsistencies and illogical positions, and I believe that if you can interpret a set of technical and engineering requirements in two ways, one of which is consistent and logical, and the other is not, then the latter must be the wrong way to interpret it.

My approach deals with the work that you do, as in "I...hereby CERTIFY that the said work for which I have been responsible is to the best of my knowledge and belief..." is what has to comply.

So what is that work?

Joining cables, so you have to comply with the regs for joints - fitness for purpose, properly rated, properly done, properly enclosed and accessible etc.

Installing cables, so you have to comply with the regs on things like current carrying capacity, protection, (inc RCD and locations if you conceal your cabling in a wall or partition etc).

As a result of the above, you should confirm by testing that you have not messed up the fault loop values, that you still have proper continuity of ring final conductors, that you still have adequate installation resistance etc.

You've (possibly) installed a new CU, so you need to certify that the MCB ratings are correct for the circuits, and record their types, you need to check the operating times of residual current detectors, and so on.

You've modified the PEBs, so you have to certify that they are OK, and if they were legacy undersized ones you have to replace them, if they were clamped to pipes in the wrong places or with the wrong clamps you have to sort that out, and so on.

All through though you are dealing with the compliance of the work for which you are responsible, and there are no inconsistencies between what you think you should sign to certify and what you can sign to certify.

The problem with the "you become responsible for the whole circuit" approach is that that is utterly impossible.

You can have no way of knowing whether 522.6.6 has been complied with and you have no realistic way of finding out. Therefore you cannot certify that the existing installation complies with BS7671:2008.

Ditto 526.3.

If a previous occupant had drilled through a ring final cable and bodged a repair, you would have no way of knowing that somewhere directly buried in plaster was a pair of 5A choc-blocks and a few cm of 0.75mm flex, nor would any testing that you carried out tell you that this had been done. So another uncertainty which stops you certifying that the existing installation complies with BS7671:2008.

And it just goes on and on and on, with reg after reg after reg, compliance with which you cannot possibly know or determine, and therefore you cannot certify.

So to pick out one or two, and use the argument that you have to do those because you're becoming responsible for the whole installation is inconsistent, and illogical, and therefore cannot be right.

 

[martinxxxxxx]

Re the botch buried in plaster bit of your post surely that is why it says

is to the best of my knowledge and belief

in the statement you sign

 

[ban-all-sheds]

So what on earth is the point of such a certification when in reality all you can truthfully say is that to the best of your knowledge and belief you have absolutely no idea if the work done by all the people who came before you is in accordance with BS 7671...?

This is exactly what I am getting at. If you think that when you sign a certificate relating to work that you did you are also signing as if you had only just done all the existing work as well, then you cannot on any meaningful basis certify in the first place.

To the best of your knowledge and belief? You have zero knowledge of what is there, so you can have zero belief that it is in accordance with BS7671. Which makes your certification meaningless, so what is the logical basis for making it, which is consistent with the intent of the regulations, and is consistent with the identical certificate and the identical assurances you would issue for completely new work for which you were responsible?

 

[RB2004]

Also.. dont mean to critiscise and put a boot in it.

But, because you are asking those questions on here on what to do.. are you competant in doing the work?

this isnt just extending a circuit, changing a fitting or fixture.. maybe adding an extra circuit which you know is sound.

the work you are planning out is effectively changing every single circuit on the system by extending the wires.. and as said previously, by crimping you need to ensure it doesnt mess up the resistance values and that the crimps are adequate.. because if it becomes a high resistance joint your then looking at it becoming a heat source and a possible fire.. in which case your insurer will not pay out and your endangering yourself.

Also, basic question, but do you own a copy of the regulations? or a guide to them as reference material?

dont mean to sound blunt.. just looking out for you, because if this goes wrong due to a lack of knowledge.. being electrics it will go seriously wrong.. especially when you have no way to isolate the incoming supply from the meter.

the interpretation of the regulations is that any circuit thats touched or worked on should always be brought up to the latest regulations, in order to test, and certify it.

So surely, anybody whos planning on extending every single circuit.. and re-wire the consumer unit should be updating to the latest regulations? because I would of thought that level of would come under the same category as actually replacing a consumer unit?

Certainly.. if you was able to certify and test.. if you didnt bring up to latest regulations.. just extended, and re-wired the consumer unit..you would then test the circuits to ensure the R values are ok and that the circuits are all good.... how would you get around not testing to the latest regulations? you would have to test to old regulations that are no longer in use.

 

[ban-all-sheds]

the interpretation of the regulations is that any circuit thats touched or worked on should always be brought up to the latest regulations, in order to test, and certify it.

Please explain how, when replacing a CU, or even just extending or modifying a circuit you would bring the existing parts of the circuit up to compliance with 522.6.6, 526.3, 433.1.5, 433.2.2 and so on and so forth - I'm sure anybody could fill a page with all of the applicable regulations.

 

[RB2004]

well surely you would start with installing a 17th edition board.. seeming as the old board is being removed to re-wire and extend the wires its a logical thing to do... then that in turn would ensure all circuits are RCD protected eigther by RCD or RCBO.

How is it logical, to remove an old edition board? and put it back up again when the opportunity can be taken to update?...the 17th edition boards were introduced to provide further circuit protection... especially for any cabling less than 50mm from the surface, and also protect lighting circuits which werent RCD protected previously.

Then basic checks like ensuring the earth bonding is adequate, and checking the state of the wiring...he has already said theres a fault on 1 of the circuits?.. surely the answer would be to trace it back and resolve that before going any further.. instead of just leaving it outside the protection of an RCD just to get around the fact the fault exists.

further highlighting the fact this person may not even be competant enough to be attempting this job.

Also if there are any inaccessible junction boxes.. it would not be impossible to do anything about them as im sure any other electrician would... cables buried less than 50mm would be resolved with the 17th edition board RCD / RCBO protecting those circuits.

At least with a 17th Edition board in place, you can then test the circuits to 17th edition regulations.

 

[ban-all-sheds]

well surely you would start with installing a 17th edition board.. seeming as the old board is being removed to re-wire and extend the wires its a logical thing to do... then that in turn would ensure all circuits are RCD protected eigther by RCD or RCBO.

So do you start out cherry picking a subset of the 17th regulations to comply with, and when you've done that you're happy to certify that the entire installation now complies?

How is it logical, to remove an old edition board? and put it back up again when the opportunity can be taken to update?...the 17th edition boards were introduced to provide further circuit protection... especially for any cabling less than 50mm from the surface, and also protect lighting circuits which werent RCD protected previously.

You may choose to do that, if you think it's worthwhile, but then you've always been able to do so - there's never been a prohibition of residual current devices being used on all circuits.

But to say you have to because you must make everything comply with the 17th cannot be other than nonsense, because it is not possible to make everything comply with the 17th. Or the 16th. Or the 15th...

Then basic checks like ensuring the earth bonding is adequate, and checking the state of the wiring...he has already said theres a fault on 1 of the circuits?.. surely the answer would be to trace it back and resolve that before going any further.. instead of just leaving it outside the protection of an RCD just to get around the fact the fault exists.

Absolutely, but that's just good practice, and not specific to 17th compliance.

Also if there are any inaccessible junction boxes.. it would not be impossible to do anything about them as im sure any other electrician would...

Err - are you seriously suggesting that to do a CU change you'd dig out all the cables buried in the walls (if you don't, you won't have any idea if there are concealed JBs or choc-blocks)? Are you seriously suggesting that you'd lift all the flooring (particularly laminate) to verify that there are no inaccessible joints?

I suspect that you aren't, but unless you do you cannot in any meaningful way say that to the best of your knowledge and belief the existing installation complies with 526.3.

cables buried less than 50mm would be resolved with the 17th edition board RCD / RCBO protecting those circuits.

OK - that gets you the tick in the box for 522.6.7.

Without exposing every single buried cable, how will you know about compliance with 522.6.6?

Unless you lift the floors, how will you know about compliance with 522.6.5?

I'm not going to list any more, but there are 10's, 100's of regulations where the same situation applies - i.e. ones where you cannot have any knowledge about the compliance of the existing installation.

So what value is there in saying "to the best of my knowledge and belief..." when your knowledge is zero?

Where is the logic in the regulations requiring you to certify that the installation complies with BS 7671 when you have no way of knowing if it does?

At least with a 17th Edition board in place, you can then test the circuits to 17th edition regulations.

No you cannot - you can only test for things like continuity, fault loop resistance, insulation resistance, RCD operating times, but they are the same requirements as before.

You might choose to increase the extent of RCD protection because you like the idea, but you've been free to do that for decades.

You might choose to increase the segregation of circuits because you like the idea, but you've been free to do that since the 1st Edition.

But you are not required to do those things until they add a specific regulation requiring any modified circuit to comply with 522.6.7 (or amend 522.6.7 itself), or ditto 314.1 etc, because such a blanket requirement would make no sense, because, as observed above, there is no way that you can certify that the existing installation complies with BS 7611:2008.

Unless of course you list every single regulation apart from 522.6.7, 314.1, and maybe a few others in the departures box, and how daft would that be?


As I say - if you choose to interpret "the said work for which I have been responsible" in a way which makes your declaration meaningless and inconsistent instead of a way which matches what the words actually say, and which does not make the declaration meaningless and inconsistent then that must make your interpretation wrong.

 

[fattony]

Thanks for that BAS much cheaper, I may be a little blind here but how the hell does that fit into a drill does it need an arbor or something?

 

[Steve]

Thanks for that BAS much cheaper, I may be a little blind here but how the hell does that fit into a drill does it need an arbor or something?

Dont think it fits in a drill. But you have to drill a pilot hole for the thing to screw into.

 

[fattony]

mmm need some clarification here please

 

[mikeyd]

mmm need some clarification here please

Punching Operation is Performed by Simply Assembling the Punch into a Pilot Hole and Tightening with an Allen Key

 

[Steve]

Sounds like it might bend the metal around it.

 

[fattony]

Really? Is it me or does it sound rubbish?

Not sure these would make a 20mm hole in galv trunking would they?

 

[RF Lighting]

They are absoloutly fantastic.

I have a slightly different one that I got from RS. It has a 17mm bolt head rather than an allen key to do the punching, so can be done with a ratchet spanner.

I don't think I've used a holesaw since I got mine. It is ideal for trunking etc, and does not deform the metalwork at all.

I'll put a pic up a bit later on.

 

[ban-all-sheds]

Sounds like it might bend the metal around it.

Nope.

Really? Is it me or does it sound rubbish?

It's you - they are superb.

Not sure these would make a 20mm hole in galv trunking would they?

Like a dream.

Re RF's comment about the ratchet spanner - that could be useful in a confined space, but in terms of effort a decent size hex key (120mm+) is fine.