Landlords test certificate.

[ban-all-sheds]

Only, as you know, if it's a ring final.

We are told it is.

We are told it is a ring final, on a 32A MCB, and it is supplying sockets.

How strongly do you wish to assert the possibility that it is not wired using 2.5mm²

As for the spur, we know that most of it probably has a CCC of 32A, and your just guessing about the last few inches/feet.

Spur or not is irrelevant.

What the spur is wired in is of no relevance whatsoever.

How many times do I have to keep saying that?

 

[ban-all-sheds]

Since the ring final itself, wired in 2.5mm² cable and protected by a 32A MCB would (given a few caveats) be allowed to supply, say, 50 x 13A sockets or FCUs, I don't really see what point you are trying to make.

The point I'm trying to make is that it is not allowed to supply a CU.

 

[JohnW2]

We are told it is. We are told it is a ring final, on a 32A MCB, and it is supplying sockets. How strongly do you wish to assert the possibility that it is not wired using 2.5mm².

I've never made such an assertion. My only comments about cable CSA have related to the (presumably very short) part of a spur between the ring and the 4mm² SWA.

What the spur is wired in is of no relevance whatsoever.

Of no relevance to what? The spur is what I have been talking about!

Kind Regards, John

 

[JohnW2]

The point I'm trying to make is that it is not allowed to supply a CU.

If that's the case, you've had a very contorted way of expressing that point.

I'm afraid that can't really get very excited about 'what is allowed' in this context. Electrically speaking, and 'safety speaking', connecting a 20A MCB (and thence whatever loads) to a ring via a spur cable of appropriate CSA is no different from connecting a double socket to the same spur (which is certainly 'allowed').

Kind Regards, John

 

[securespark]

I don't have the yellow book, being retired I see no pressing need to stay bang up to date, but I can't see the business about 1363 being as clear cut as you see it, Ban.

However, I'm not keen on wiring this arrangement, as if the spur was well-loaded (setting aside any worries about being centrally fed etc), it would not leave a great deal for the ring final.

 

[ericmark]

Items complying with BS EN 61558-2-5 and BS 4573 can also be supplied from a ring final as well as those to BS 1363 and often are, the words "May" and "Must" are very different.

"Every circuit shall be designed so that a small overload of long duration is unlikely to occur." is the main point, and where a house has a single ring final for whole house there is a far higher chance of overload than where there are two or more ring finals, with the latter it is very likely that the ring final feeding the bedrooms will only have a very light load, where the one feeding the kitchen/Utility rooms will have a high load specially where fixed equipment has not been supplied with dedicated supplies.

As with any building things can change over time, and what seemed reasonable at the time of fitting may in years to come no longer seem reasonable. But here we it seems are talking about a small time period between the shed being wired and the EICR being completed to re-test with less than a year between the two tests does seem pointless unless there is some good reason to believe the installation was not correctly done.

It may be that the landlord has many properties and has found work done by the electrician who wired the shed was sub-standard in other properties and may be the EICR was to find out if there was any other work sub-standard done with other property he owned? However the tester should be talking to the owner or letting agent not the tenant, and the owner or letting agent should have informed the tenant before the testing electrician arrived and should have agreed time and what disruption was acceptable.

I know when I visit my daughters house she needs to talk to her husband before we kill the power as he remotely accesses the home PC from work, and with my mother I have a remotely accessed camera, in both cases warning is required except in cases of emergency. To me the problem is more to do with communications than the testing, people do need to write and talk to each other.

 

[ban-all-sheds]

Of no relevance to what?

To the "legality" of supplying a CU from a ring final.

The spur is what I have been talking about!

I know.

But I do not understand why, when that is of no relevance to the "legality" of supplying a CU from a ring final.

If that's the case, you've had a very contorted way of expressing that point.

Not really:

Lord knows why we've had all of the chat about the loading of the cable to the shed CU, how and where it's protected, whether the loading on the ring is balanced or not, whether it is or is not any worse than a spur supplying a double socket, whether people would be happy to do it in their houses but not customers, or and in customers etc etc etc.

The regulations are absolutely clear and easy to understand, so much so that I'm convinced that anybody who argues otherwise is not doing so because they think they say something else, but because they don't want them to say what they do.

If you have a ring final you may only use it to supply BS 1363 accessories.

And that's the end of it - if the "electrician" who installed the shed supply certified BS 7671 compliance then he was not telling the truth. It does not comply.

I'm afraid that can't really get very excited about 'what is allowed' in this context.

That does not surprise me - it would not be the first time you'd said that you don't care what BS 7671 says and how you quite happy to ignore any or all of it.

Electrically speaking, and 'safety speaking', connecting a 20A MCB (and thence whatever loads) to a ring via a spur cable of appropriate CSA is no different from connecting a double socket to the same spur (which is certainly 'allowed').

The CU MCBs total 26A.

But that is irrelevant - using a ring final to supply a CU contravenes the regulations, and this work was done by a registered electrician who (presumably) therefore issued an EIC for it.

 

[ban-all-sheds]

I don't have the yellow book, being retired I see no pressing need to stay bang up to date, but I can't see the business about 1363 being as clear cut as you see it, Ban.

Nothing has materially changed since the earlier edition(s) you have.

To summarise:

433.1.1 [A set of rules defining the required coordination between conductor and OPD]

433.1.204 [How accessories to BS 1363 may be supplied through a ring final with a 30/32A OPD and how provided the cable and its load meet certain requirements it is deemed to comply with 433.1.1]

 

[JohnW2]

Electrically speaking, and 'safety speaking', connecting a 20A MCB (and thence whatever loads) to a ring via a spur cable of appropriate CSA is no different from connecting a double socket to the same spur (which is certainly 'allowed').

The CU MCBs total 26A.

In the OP's case, they do. However (a) at least some people regard a double socket (which you would regard as compliant) as also representing a potential load of 26A, and (b) I imagine that you would be saying exactly the same if the CU's MCB(s) totalled 20A, 12A, 10A or even 6A.

... using a ring final to supply a CU contravenes the regulations

That is your interpretation of the regulations but, as you are aware, although your view probably does reflect the actual words of the regulation, not everyone shares your interpretation - and (FWIW) common sense certainly does not share that view.

Kind Regards, John

 

[ban-all-sheds]

Items complying with BS EN 61558-2-5 and BS 4573 can also be supplied from a ring final as well as those to BS 1363

No they may not.

Unless you want to try the daft idea of asking me to prove a negative, the position is that I say they may not, and tell you that you are perfectly free to prove me wrong and you right by quoting the regulation which allows items complying with BS EN 61558-2-5 and BS 4573 to be supplied by a circuit which does not comply with 433.1.1

and often are

Really?

They are often supplied by a ring final where the CCC of the cable used is less than the rating of the OPD?

I find that hard to believe.

the words "May" and "Must" are very different.

Of course they are, and for 433.1.204 to say "must" would be ludicrous, as it would prevent radials being used.

I really don't understand how you can look at a regulation saying "X may be supplied through..." and see "X and Y may be supplied through..."

 

[ericmark]

To the "legality" of supplying a CU from a ring final.

The is nothing legality to stop anyone feeding a CU from a ring final. BS7671 is not a legal document although following it's recommendations is one way to show due care and attention was used and the electrician had a warranty of skill.

As I have already said fitting shaver sockets through an isolating transformer is permitted from a ring final and these are not to BS 1363 there is a massive difference between the word "May" and "Must".

I would agree it would not be my preferred method to feed a shed from a ring final, however if I was doing an EICR on one which was already fitted then I would find it hard to quote the regulation number which said it was not permitted. The only possible reason to fail it assuming correct size of cables etc would be massive overloading of one leg of the ring. In this case it states a 20 A MCB has been used to limit the current draw so it has same draw as permitted from a single double socket. So unless we are going to condemn double sockets we can hardly condemn the shed.

 

[ericmark]

No they may not.

Unless you want to try the daft idea of asking me to prove a negative, the position is that I say they may not, and tell you that you are perfectly free to prove me wrong and you right by quoting the regulation which allows items complying with BS EN 61558-2-5 and BS 4573 to be supplied by a circuit which does not comply with 433.1.1

You really believe that you can't supply a shaver socket to BS EN 61558-2-5 or BS 4573 from a ring final? Come on get real.

 

[stillp]

there is a massive difference between the word "May" and "Must".

FWIW the word "must" is not used in standards, it is reserved for legislation. The imperative form is "shall". "May" is used to give permission, "can" is used to express a possibility. The latter two are often confused.

 

[JohnW2]

You really believe that you can't supply a shaver socket to BS EN 61558-2-5 or BS 4573 from a ring final? Come on get real.

I imagine that BAS probably does believe that, since his view is consistent with a literal interpretation of the words of the regulation. If the regulations had been 'perfectly' drafted, such that they ended up sensible and exhaustive, we would not need to have all these discussions. As things are (imperfect), my personal opinion is that a degree of common sense needs to be exercised.

... and what about JBs which, although they are not 'accessories to BS1363' feature extensively in Appendix 15?!

Kind Regards, John

 

[ban-all-sheds]

I imagine that you would be saying exactly the same if the CU's MCB(s) totalled 20A, 12A, 10A or even 6A.

Of course I would, because that is what the regulations say.

That is your interpretation of the regulations but, as you are aware, not everyone shares your view

How can you possibly dismiss it as my "interpretation"?

433.1.204 Accessories to BS 1363 may be supplied through....

It does not say that anything else may be supplied through..., so if you are supplying something else how can you use its special "deemed to meet the requirements of Regulation 433.1.1" provision?

The regulations are absolutely clear and easy to understand, so much so that I'm convinced that anybody who argues otherwise is not doing so because they think they say something else, but because they don't want them to say what they do.