1 OR 1.5mm twin & earth cable for bathroom LED downlighters... discuss

[ban-all-sheds]

Is that a reflection on the fact that there is no regulation which explicitly states that, or what?

Well, it's not "or what".

"Unless it were a fused spur, you are only allowed one (single or double) socket on a spur from a ring final circuit."

Which regulation says that?

Electrically speaking, the cable of a 2.5mm² unfused spur (from a 32A ring) could theoretically become overloaded with anything more than two '13A outlets' on the spur (even with Method C)

More than. But not equal to.

So 2 single sockets would not create the potential for an overload. Nor 3 single sockets for a 6mm² unfused spur.

 

[JohnW2]

"Unless it were a fused spur, you are only allowed one (single or double) socket on a spur from a ring final circuit." ... Which regulation says that?

As I said/implied, no regulation says that explicitly.

We've often discussed the irrationality of the distinction between one double and two single sockets (as per Appendix 15). Whether vone regards the 'rating' of a double socket as 20A or 26A, there is no doubt that in terms of ('downstream') overload protection, both a double socket and two single sockets potentially represent 26A of 'protection'. In either case, that is just enough to protect a Method C 2.5mm² cable (the only other protection being the 30/32A circuit OPD), and it is equally clear that the fuses in 3 (or more) '13A outlets' (3 singles or one single plus one double) would not necessarily provide adequate overload protection for the 2.5mm² cable.

Kind Regards, John

 

[ban-all-sheds]

As I said/implied, no regulation says that explicitly.

And you wondered why I replied the way I did when you wrote "Unless it were a fused spur, you are only allowed one (single or double) socket on a spur from a ring final circuit"?

 

[JohnW2]

And you wondered why I replied the way I did when you wrote "Unless it were a fused spur, you are only allowed one (single or double) socket on a spur from a ring final circuit"?

Yes, I wondered, and, although I could think of no other interpretation sought your confirmation.

We always have to remember that this is a DIY forum, and that, in this case, the comment of mine you questioned was directed at the OP, who clearly has limited knowledge/understanding of things electrical. You, myself and maybe some of the electricians here might be prepared to contemplate having to justify how/why what had been done was compliant with Part P despite being contrary to the guidance in an Appendix of BS7671, but the average DIYer would not be so able, so I think it very reasonable to advise them on the basis of that guidance, even though you, I and others might disagree with that guidance (and wouldn't ourselves necessarily feel compelled to 'comply' with it).

Kind Regards, John

 

[ban-all-sheds]

You are starting to sound like the plumbers who cheerfully lie to people as it's easier than telling the truth.

Designing circuits is not rocket science, but neither is it utterly trivial and it is wholly wrong to try to make it so.

If the concepts involved are outwith the limited knowledge/understanding of a DIYer then it behoves the DIYer to either expand his knowledge/understanding or abandon the idea of trying to do electrical design work.

 

[JohnW2]

You are starting to sound like the plumbers who cheerfully lie to people as it's easier than telling the truth.

"Lie" is, in my opinion, a far too emotive a word. Provided that one errs in the right direction, it is often sensible to provide 'simplified' answers/advice, and that is likely to be welcomed by the recipients.

Designing circuits is not rocket science, but neither is it utterly trivial and it is wholly wrong to try to make it so. If the concepts involved are outwith the limited knowledge/understanding of a DIYer then it behoves the DIYer to either expand his knowledge/understanding or abandon the idea of trying to do electrical design work.

The issue we are discussing is not limited to DIYers, nor does it necessarily relate to limited knowledge/understanding. Whilst many of them could probably respond, perhaps successfully, to an accusation that what they had done was 'not acceptable', I very much doubt that (m)any electricians would install more than one accessory (e.g. two single sockets) on the same unfused spur from a ring final. If that is the case, it seems appropriate to give corresponding advice to a DIYer.

Kind Regards, John

 

[HawkEye244]

Out of interest can 1mm be used on sockets without issue ?

 

[JohnW2]

Out of interest can 1mm be used on sockets without issue ?

No, unless one can argue that the sockets are on a 'lighting circuit'. For whatever reason (which many/most of us think is daft), the regs make a distinction between 'lighting circuits' and 'power circuits', and impose a minimum cable size of 1.5mm² for the latter.

To be honest, there are relatively few situations in which even 1.5mm² is appropriate anywhere in a sockets circuit, so it will usually be at least 2.5mm².

Kind Regards, John

 

[ban-all-sheds]

"Lie" is, in my opinion, a far too emotive a word.

"Unless it were a fused spur, you are only allowed one (single or double) socket on a spur from a ring final circuit."​

Is that true, or false?

 

[JohnW2]

"Unless it were a fused spur, you are only allowed one (single or double) socket on a spur from a ring final circuit.". Is that true, or false?

Good grief. I've already agreed that there is no regulation which says that.

I have also just told you that, presumably because of what is said in ('informative') 'guidance' in an Appendix of the Wiring Regulations, I believe that almost all electricians will work as if there were such a regulation. If that is how electricians feel about the situation, I personally believe that it is appropriate to give that 'advice' to a DIYer - whether you choose to call it "lying" or anything else.

So many of your posts these days fail to offer anything useful to those who come here to seek advice - which is a great pity, given how much valuable assistance we know you are capable of providing.

Kind Regards, John

 

[ban-all-sheds]

Good grief. I've already agreed that there is no regulation which says that.

So you knew it was untrue when you wrote it.

Did you intend that people reading it should believe that it was true?

I have also just told you that, presumably because of what is said in ('informative') 'guidance' in an Appendix of the Wiring Regulations, I believe that almost all electricians will work as if there were such a regulation.

Irrelevant.

If there is not such a regulation then there is not, no matter how many people work as if there is.

If that is how electricians feel about the situation, I personally believe that it is appropriate to give that 'advice' to a DIYer - whether you choose to call it "lying" or anything else.

There are a number of ways in which you could have imparted that advice without resorting to known untruths intentionally told in order to mislead.

As I said - you're behaving like some of the plumbers who try to rationalise telling people things which they know to be untrue on the grounds that it is "simpler" than telling the truth.

So many of your posts these days fail to offer anything useful to those who come here to seek advice - which is a great pity, given how much valuable assistance we know you are capable of providing.

Except when that valuable assistance is provided to you regarding telling the truth.