CU Change under 17th

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If you were to replace a rewirable fuse box to 17th edition, would you have to RCD protect all exitsting ccts less than 50mm/not mechanically protected/in earth metallic conduit etc etc ?

As there has never been a requirement to bring all work to current regs I think not, but if you do then CU changes will become a lot more expensive !
 
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I've just quoted & it's been accepted on a cu change £620 (any faults to circuits will be extra)

Thats for 9 circuits all on rcbo's/ 12way cu / & install Equip bonding to gas & water.
 
Not read all the new red book yet but no previous Regs have been retrospective. I wouldn't have thought purely replacing a CU would in itself require re-chasing of cables for example. You'd clearly need to test everything before a CU change to see what problems that change may create.

Standing by to be flamed
 
Given the price of 9 RCBO's alone that must account for over half the cost of that install.
 
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I guess my concern is that by replacing the CU you effectively have to ensure compliance of the whole installation. Now you could argue that the routing/protection of the existing circuits complies with 16th edition, fine. However, the consumer unit must comply with 17th, as its new (not a like for like replacement). Therefore you could argue that under the 17th the consumer unit must be installed and equipped to offer additional RCD protection to cables installed in safe zones but less than 50mm.

A comparison to make is the addition of a socket on a ring final with no RCD. The new socket must be protected by an RCD if it could reasonably be expected to supply equipment outdoors.
 
As there has never been a requirement to bring all work to current regs I think not

Not my understanding of BS7671 for a CU change Chapter 74 brown book - haven't got the red book yet, as I'm working to 16th until June.

There is no problem working to 17th before they become extant but the installation must comply with one or the other not some of one some of the other

When changing a CU you are altering the characteristics of whole installation.
 
I guess my concern is that by replacing the CU you effectively have to ensure compliance of the whole installation. Now you could argue that the routing/protection of the existing circuits complies with 16th edition, fine. However, the consumer unit must comply with 17th, as its new (not a like for like replacement). Therefore you could argue that under the 17th the consumer unit must be installed and equipped to offer additional RCD protection to cables installed in safe zones but less than 50mm.
You could argue all that, but not for long, please, as your horse would be getting restless outside.... ;)

A comparison to make is the addition of a socket on a ring final with no RCD. The new socket must be protected by an RCD if it could reasonably be expected to supply equipment outdoors.
The new socket, yes, not all the others.

The comparison to make is a new circuit, or new switch drops etc under the 17th. They will have to comply with the latest requirements, but not all the existing cables.

It's going to take generations for all the old stuff to be replaced, by which time who knows how many other editions will come and go, so nobody is ever going to be able to rely safely drilling into walls without thinking, so you wonder what the point is...
 
As there has never been a requirement to bring all work to current regs I think not

Not my understanding of BS7671 for a CU change Chapter 74 brown book - haven't got the red book yet, as I'm working to 16th until June.
I can't see anything in 16th Ch 74, or 17th DPC Ch 63 which requires you to bring an entire installation up to current standards if you replace a CU.

There is no problem working to 17th before they become extant but the installation must comply with one or the other not some of one some of the other
But that happens all the time. You install an outdoor socket, so you RCD protect it because the 16th says so, but you don't have to put every other socket on a RCD.

You install a shower circuit in a house with no lighting cpc - you don't have to rewire the lighting circuit.

When changing a CU you are altering the characteristics of whole installation.
Not necessarily, but even when you are, you only have to ensure that the work you do complies with the current regulations.
 
I am neither a qualified electrician nor a troll but I ask this out of genuine interest as it will affect me when I finally replace my CU (with appropriate tests and BCO approval).

I accept that you shouldn't have to chase out and install mechanical protection on the existing circuit but surely any protective device you install in the new CU must comply to current regs? i.e. 17th when it is in force.

Please humour me and consider the following scenario

You are changing an old rewirable CU for a new one.
You find that one of the circuits,installed in 1950, feeds only outside sockets.
That circuit is not currently RCD protected.

If you energise that circuit from your new CU without RCD protection (using the argument that it wasn't on RCD before and you haven't altered that circuit) are you complying with the regs?

Is there any significant difference (in terms of regs compliance) between that scenario and the one posed by the OP?

If the answer is still as above (no need for RCD under 17th) then the job will be cheaper for me so happy days!
 
If you energise that circuit from your new CU without RCD protection (using the argument that it wasn't on RCD before and you haven't altered that circuit) are you complying with the regs?
I would say so. You did not install the sockets, so the issue of whether they comply now is irrelevant.

I've never bought into the superstition that if you change a CU you somehow become "responsible" for the entire installation.
 
I guess my concern is that by replacing the CU you effectively have to ensure compliance of the whole installation. Now you could argue that the routing/protection of the existing circuits complies with 16th edition, fine. However, the consumer unit must comply with 17th, as its new (not a like for like replacement). Therefore you could argue that under the 17th the consumer unit must be installed and equipped to offer additional RCD protection to cables installed in safe zones but less than 50mm.
You could argue all that, but not for long, please, as your horse would be getting restless outside.... ;)

Why do you insinuate I am a cowboy when I pose a reasonable argument that regulations are not retrospective ? (and then go on argue the very same yourself??)

A comparison to make is the addition of a socket on a ring final with no RCD. The new socket must be protected by an RCD if it could reasonably be expected to supply equipment outdoors.
The new socket, yes, not all the others.

I know, that exactly what I said. :rolleyes:

ban-all-sheds said:
I've never bought into the superstition that if you change a CU you somehow become "responsible" for the entire installation.

Then please explain to me how you complete an EIC on an installation that you have just changed the CU where there are areas that were unsatisfactory before your work, e.g. a ring final circuit without continuity of the CPC.

You can't complete an EIC with a fail on any item. You may put "LIM" on an inspection such as routing of cables as you cant see them within the fabric of the building. In changing the CU you have modified every circuit, and possibly the supply and earthing and bonding.
 
Why do you insinuate I am a cowboy when I pose a reasonable argument that regulations are not retrospective ? (and then go on argue the very same yourself??)
Did you not see the ;) ?

But I did drop a clanger in not reading what you wrote properly, because I was distracted by your first sentence - I thought you were saying that you could argue that the changes in the 17th meant that people would have to have work done to bring their installations up to the standards of the 17th. I didn't say that you were a cowboy, just that if you did argue that as a way to get more money then that would be a cowboy-ish thing to do.

ban-all-sheds said:
I've never bought into the superstition that if you change a CU you somehow become "responsible" for the entire installation.

Then please explain to me how you complete an EIC on an installation that you have just changed the CU where there are areas that were unsatisfactory before your work, e.g. a ring final circuit without continuity of the CPC.
That's a special case, as that is explicitly catered for in 131.8

You can't complete an EIC with a fail on any item.[/quote]
Well - from a generic POV you can if you include things on there that you didn't do.

Read the declaration carefully - I'll highlight a very important part of it:

I being the person responsible for the Design, Construction, Inspection & Testing of the electrical installation (as indicated by my signature below), particulars of which are described above, having exercised reasonable skill and care when carrying out the Design, Construction, Inspection & Testing, hereby CERTIFY that the work for which I have been responsible is to the best of my knowledge and belief in accordance with BS 7671.....

The work for which you have been responsible.

i.e. the installation of the CU. You were not responsible for the existing parts of the installation which failed.

Whether as a conscientious professional you should leave the faults unattended to is a separate issue, but the fact is that the declaration on the EIC is clear - you are only certifying what you did.

You may put "LIM" on an inspection such as routing of cables as you cant see them within the fabric of the building.
Interesting that you should mention testing, as this is another common misconception, that you can't sign the I&T part of a 3-part EIC if the installation is dodgy.

The declaration there reads (with one minor change to make it clearer):

I/We being the person(s) responsible for the inspection & testing of the electrical installation (as indicated by my/our signatures below), particulars of which are described above, having exercised reasonable skill and care when carrying out the inspection & testing hereby CERTIFY that the inspection & testing for which I/we have been responsible is to the best of my/our knowledge and belief in accordance with BS 7671...

So you aren't certifying that the installation complies with BS7671, you are certifying that the inspection & testing you did complies with it.

The installation might be a pile of poo, and in that case, to paraphrase the declaration in combination with the schedule of results, what you are saying is "I have inspected and tested this installation in accordance with BS7671 and I find it to be a pile of poo".

In changing the CU you have modified every circuit, and possibly the supply and earthing and bonding.
As said, earthing and bonding are explicitly catered for.

But moving away from that, let's say you found that a circuit was too long, and would not meet disconnection times. The way to resolve that and ensure that your work, i.e. the installation of the CU, complies with BS7671 is to put a smaller breaker in, not to fix the actual problem of the circuit. Again, the question of what a conscientious professional would prefer to do is separate, and it may come down in some cases to refusing the job.

But that's a personal standards issue, not a British Standards one.
 
Why do you insinuate I am a cowboy when I pose a reasonable argument that regulations are not retrospective ? (and then go on argue the very same yourself??)
Did you not see the ;) ?

But I did drop a clanger in not reading what you wrote properly, because I was distracted by your first sentence - I thought you were saying that you could argue that the changes in the 17th meant that people would have to have work done to bring their installations up to the standards of the 17th. I didn't say that you were a cowboy, just that if you did argue that as a way to get more money then that would be a cowboy-ish thing to do.


Is that an apology then, as I find the "C" word to be very insulting ! ;)




Interesting that you should mention testing, as this is another common misconception, that you can't sign the I&T part of a 3-part EIC if the installation is dodgy.


Whether its a 3 part or one part, the fact remains that other than only for a PIR where LIM or X can be entered, you must enter a tick to say the result is satisfactory. Your argument therefore would mean that all inspections and tests relate, in this instance of a CU change, only to the actual consumer unit installation, and not the final circuits, which I think is unacceptable.

Back to the original question, when changing a CU post July 2008, do all circuits with concealed cables < 50mm require RCD protection ? I will try the NICEIC for their stance.
 
"Whether its a 3 part or one part, the fact remains that other than only for a PIR where LIM or X can be entered, you must enter a tick to say the result is satisfactory. Your argument therefore would mean that all inspections and tests relate, in this instance of a CU change, only to the actual consumer unit installation, and not the final circuits, which I think is unacceptable."

I can't find that in the regs - can you provide a page & para. reference please? If it's not in the regs but just what NIC and/or other trade bodies require, then that is only relevant to their members as they don't write the regs.
 

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