Socket behind dishwasher pt.2 - are we being had?

[JohnW2]

It's a matter of opinion. I note, for example, that Mark Coles wrote the following a number of years ago in the IET Wiring Matters publication: "Some installers are of the opinion that when adding to an existing circuit, provided that the existing circuit meets the requirements of BS 7671:2001(2004), i.e. the 16th Edition, then the 17th Edition simply applies to the new addition. This article shows that in all cases, the 17th Edition is to be applied to the entire circuit worked on."

Despite what he wrote, I cannot see that his article can "show that" anything - it is merely his interpretation/opinion.

However, I've already said that, in the case of RCD protection of sockets, if they want a requirement for RCD protection, it would probably have made more sense if they had explicitly required that the entire circuit be RCD-protected if anything were added to it. Although I take BAS's point about the need to manage transition periods (after introduction of new requirements) 'somehow', to require one out of maybe a dozen or more sockets on a circuit to be RCD protected does not really sit well with common sense - particularly since providing RCD protection for the entire circuit will often not be much more difficult, and not necessarily appreciably more expensive, than providing RCD protection for just one new socket.

Kind Regards, John

 

[Risteard]

Is that confirmed by a regulation or is it merely Mr.Coles' opinion?

"No less safe" springs to mind for some reason.

Yes. Regulations are quoted. The article can be found at: electrical.theiet.org/wiring-matters/30/additions.cfm?type=pdf

 

[Risteard]

Despite what he wrote, I cannot see that his article can "show that" anything - it is merely his interpretation/opinion.

It is of course. Although as Technical Regulations Manager his opinion is hardly unimportant. My point was simply that this claim that only the new part of the wiring needs to comply with the Regulations is merely an opinion and should not be taken as established fact - there is certainly evidence to support the contrary view.

 

[JohnW2]

It is of course. Although as Technical Regulations Manager his opinion is hardly unimportant. My point was simply that this claim that only the new part of the wiring needs to comply with the Regulations is merely an opinion and should not be taken as established fact - there is certainly evidence to support the contrary view.

Agreed. However, I think it is fair to say that most people do appear to regard that view as almost "established fact". Taking this forum, and the matter of RCD protection of sockets, as an example, the options of adding an RCD-socket, or adding a socket fed via an RCD-FCU is nearly always mentioned as a possible approach (when the circuit as a whole is not RCD-protected), and I cannot recall ever having seen anyone suggest that such an approach would not be acceptable/compliant.

Similarly, if one extended that view, if a circuit including any buried cable was 'worked on', there would be a requirement to RCD protect the entire circuit (even if there were no other reason for needing RCD protection) - and, again, I do not recall ever having seen that suggested.

Kind Regards, John

 

[Risteard]

Personally I have sympathy with the view that the entire circuit should be upgraded. (And before anyone gets silly I am not talking about things like remarking all old cable terminations brown and blue.)

 

[EFLImpudence]

I think Mr.Coles' opinion, that the whole circuit shall be brought up to date, hinges on this piece -


"In Regulation 120.3, the key words are "The resulting degree of safety of the installation shall be not less than that obtained by compliance with the Regulations".

in which case it would seem to depend on the meaning of installation.
The definition of (Electrical) Installation in Part 2 does not help.

 

[EFLImpudence]

Of course, the everyday definition could be applied -

so - latest regulations being limited to the new socket would seem to fit the bill.

 

[JohnW2]

I think Mr.Coles' opinion, that the whole circuit shall be brought up to date, hinges on this piece - "In Regulation 120.3, the key words are "The resulting degree of safety of the installation shall be not less than that obtained by compliance with the Regulations". .... in which case it would seem to depend on the meaning of installation.

Is there not a potential problem with that? The vast majority of new regulations, or changes in regulations (particularly the sort of regulations we've been talking about) presumably exist because they are perceived as representing an improvement/increase in safety' in comparison with previous regs. That being the case, would they not have to regard anything non-compliant with the current regulations (even if compliant with previous regulations) as being "less safe than that obtained by compliance with the [current] regulations"??

Kind Regards, John

 

[EFLImpudence]

Are you saying that it means the whole house (installation) should be brought up to date?

 

[EFLImpudence]

Ah. I have quoted the wrong part - which applies to 'departures'.

The relevant part is earlier in the article but I still disagree with Coles' opinion.

 

[JohnW2]

Are you saying that it means the whole house (installation) should be brought up to date?

I don't know. I suppose what I'm saying is that, if one takes this concept of "no less safe than under current regulations" anywhere beyond "just the new work", then it's difficult to know where one would stop.

Kind Regards, John

 

[securespark]

Yes. But I can't find the relevant area. I had an idea it was right at the front, but I can't see it.

 

[JohnW2]

Yes. But I can't find the relevant area. I had an idea it was right at the front, but I can't see it.

It doesn't really say all of what we 'want', but ...

...Existing installations that ave been installed in accordance with earlier editions of the Regulations may not comply with this edition in every respect. This does not necessarily mean that they are unsafe for continued use or require upgrading....

Kind Regards, John

 

[EFLImpudence]

He also quotes what is now 110.1.2(vi):

"Additions and alterations to installations and also parts of the existing installation affected by an addition or alteration"

with the comment:

Note the words "... parts of the existing installation affected by an addition or alteration"

so, then it comes down to what you consider as 'affecting'.

 

[JohnW2]

Note the words "... parts of the existing installation affected by an addition or alteration" .... so, then it comes down to what you consider as 'affecting'.

Indeed. In the present context, I don't think that it could sensibly be suggested that adding an extra socket in any way 'affects' the pros/cons of having/not having RCD protection for pre-existing sockets on the circuit, could it?

Kind Regards, John