Landlords test certificate.

[EFLImpudence]

However, I have to ask again, would you be happy to use 20A + 6A OPDs to protect such a circuit in a customer's house (or to connect multiple sockets to a ring final via a 20A (or 25A) OPD, rather than through an FCU)?

I just thought that might be what the installer was thinking.

The 'multiple sockets' you mention would be no different fed through a 13A FCU. Their loadings are irrelevant for the argument.
If you think multiple sockets on a spur must be fed through a 13A FCU despite the cable being adequate for the 32A ring OPD then I would have thought you would have stated it should be a 15A OPD in the shed.

 

[JohnW2]

I just thought that might be what the installer was thinking.

Maybe - but as witness the existence of threads like this one, a problem of any arguably 'unconventional' or potentially controversial thinking on the part of the designer is that an inspector who subsequently comes along might not agree with that thinking. I would say that, at the very least, a designer who had utilised such thought processes should leave behind a detailed explanation of his/her thinking - for the benefit of that subsequent 'inspector'.

The 'multiple sockets' you mention would be no different fed through a 13A FCU. Their loadings are irrelevant for the argument.

I don't really understand that. If multiple sockets are fed through an FCU (or any other OPD), that obviously limits the total current that they can draw, no matter what loads the user maytry to plug in.

If you think multiple sockets on a spur must be fed through a 13A FCU despite the cable being adequate for the 32A ring OPD ....

As I've said, I do not personally think that (as a generalisation) - the crucial issue being whether or not I am fairly confident that the short leg of the ring is not going to be overloaded by potential/"likely" high point loads. However, as I've said, I do rather doubt that many electricians would be happy to do it.

We can but speculate about 'intent', but I suspect that the guidance of Appendix 15 (which I gather was once a regulation) may well have been conceived far more as a means of reducing the probability of high point loads on the ring than having anything to do with cable CCC - and, if I'm right, then that would probably also explain a (deliberate) omission of a 4mm² unfused spur supplying multiple sockets from App 15.

Kind Regards, John

 

[EFLImpudence]

The 'multiple sockets' you mention would be no different fed through a 13A FCU. Their loadings are irrelevant for the argument.

I don't really understand that. If multiple sockets are fed through an FCU (or any other OPD), that obviously limits the total current that they can draw, no matter what loads the user may try to plug in.

So does the 20A in the shed - my original point.

 

[securespark]

I used to inspect about 20% on each circuit. If I found anything untoward, I would inspect a few more.

I wouldn't be happy finding this "spur" off the ring final.

 

[JohnW2]

I don't really understand that. If multiple sockets are fed through an FCU (or any other OPD), that obviously limits the total current that they can draw, no matter what loads the user may try to plug in.

So does the 20A in the shed - my original point.

Indeed - and, although it is probably 'unconventional', I doubt that many could come up with a good electrical argument for it not being acceptable to run multiple sockets off that 20A OPD ...

... the (pedantic) issue is the "...and a 6A OPD". Yes, the lighting load will almost certainly be trivial. However, we very regularly see people here being told that they cannot ('are not allowed to') feed a FCU for a fan (maybe 0.05A or so) from an unfused spur "because that would be taking a spur from a spur" (even if their cable has a CCC of 27A). It's electrical nonsense, but a lot of people, including many electricians, seem to feel that they have to give that advice.

Someone doing an EICR in my house would have a field day - I have (trivial load) 'spurs off spurs' (and probably some 'spurs off spurs off spurs) all over the place!

Kind Regards, John

 

[ericmark]

When I took my C&G2382 7% of the marks i.e. two questions were on the appendix it therefore seems C&G believe that the appendix is part of BS7671:2008 even if it is called the appendix.

I don't see anything wrong with extending a ring with a 6mm² cable to some remote location as long as "The load current in any part of the circuit should be unlikely to exceed for long periods the current-carrying capacity of the cable (Regulation 433.1.5 refers)." and the appendix makes that clear. So in real terms it needs to be taken form some where near the centre of the ring. The idea is the cable is rated 20A x 2 and the MCB is rated 32A so the resistance in each leg of the ring should not allow more than 20A to be drawn in that leg. However in this case a 20A MCB limits the draw to 20A. However if not central then loads on the house sockets could still cause the load on one leg to exceed the 20A limit for a long period.

The electrician would need to satisfy himself that there would unlikely be an overload due to the shed supply and there is really no hard and fast rules as to where on the ring he could take the supply from and be assured this would be the case. My concern would be how one can show one has complied with 433.1.5 unless it is reasonable central? Using 5 core SWA and extending the ring could result in exceeding the ELI and volt drop in the house and so if one has to use the ring final then may as well take it as a spur although in a heavy cable.

Of course one could take it from the CU and be just using the same fuse there would be nothing to stop that.

However the point is the electrician has completed and issued the paperwork and it has been submitted to the scheme provider who has one assumes in turn informed the LABC who should record this some where on their system. So in theroy one could with the freedom of information act request from the LABC the record of work done to any house. Never tried but it would be interesting to see the result. In real terms I suspect this would only happen if something went wrong. i.e. an electrocution. But in theroy we could find out from the council.

I was under the impression that the installation certificate had to be submitted to the scheme provider in the same way as non scheme members submitted it to the LABC. However it seems this is not the case. So if there was a problem with the wiring no one in the future can request copies from anyone who is assured to be still trading.

So I see a problem where the shed has been fed from the ring with an EICR as one likely can't verify the work was done by some one who did work out correctly the loadings. Which means one has to work it out yourself. Now you only have four options. 1) Its OK, 2) The should be some improvement. 3) It is potentially dangerous. 4) It is dangerous. Note non of these refer to BS7671 being followed, although the IET PDF seems to say not following current regulations could be given a code 3. It seems to imply that the old 3 and 4 have been combined to give code 3. (Winter 2011 Wiring Matters)

So now down to nitty gritty could an electrician doing an EICR give a code 3 to wiring a shed with an automatic disconnection of 20A to the ring final? I would say no, as one can't show it would cause an overload in either leg of the ring final. I see a slight difference between the installation certificated and the EICR with the installations certificate you and saying it is compliant and safe with the EICR your saying it's not compliant and safe so any boarder line issues will not be highlighted with an EICR.

 

[JohnW2]

When I took my C&G2382 7% of the marks i.e. two questions were on the appendix it therefore seems C&G believe that the appendix is part of BS7671:2008 even if it is called the appendix.

I suppose that C&G are free to examine on whatever they wish, but BS7671 itself is very clear in saying that all Appendices other than Appendix 1 are only "informative and provided for guidance" and are not regulations.

I don't see anything wrong with extending a ring with a 6mm² cable to some remote location as long as "The load current in any part of the circuit should be unlikely to exceed for long periods the current-carrying capacity of the cable (Regulation 433.1.5 refers)." and the appendix makes that clear. So in real terms it needs to be taken form some where near the centre of the ring. ... However if not central then loads on the house sockets could still cause the load on one leg to exceed the 20A limit for a long period.

Indeed. However, if (as is common) the CCC of the cable in 27A (rather than to 20A minimum), then it is not that difficult to satisfy oneself about that requirement - if the origin of the spur is then not within about 18% of total ring length from one end (and if total load on circuit does not exceed 32A), then it is impossible for even a 'full 32A' in the spur to overload any of the ring cable. If the CCC of the cable is only the ('minimum') 20A, then the spur would obvioulsy have to originate much closer to the centre of the ring.

So I see a problem where the shed has been fed from the ring with an EICR as one likely can't verify the work was done by some one who did work out correctly the loadings.....

Indeed - which is why I said that if a designer does something a little 'unconventional' like that, they really should leave behind a detailed description of how they arrived at their design.

Kind Regards, John

 

[ericmark]

So I see a problem where the shed has been fed from the ring with an EICR as one likely can't verify the work was done by some one who did work out correctly the loadings.....

Indeed - which is why I said that if a designer does something a little 'unconventional' like that, they really should leave behind a detailed description of how they arrived at their design.

Kind Regards, John

The point is in this case the information should be left with the home owner, and when that owner is not the occupier then it should be passed to the person doing the EICR at the time of ordering the work, and arrangements should be made with the tenant as to when this work should be done.

However the question arises as to the duties of a letting agent. It is likely that the letting agent does not have paperwork such as installation certificates and if they don't have that paperwork then they should not really be arranging for inspections.

I have never either been tenant or landlord but my son and daughter were a tenants for a number of years, and I have seen the problems. My daughter would act as if she owned the house, and my son would ask for what I considered unreasonable work. He expected RCD protection what ever age the house was and he's comment was my own house had RCD protection why should the landlord get away without providing it. However my point was he knew it was not there before he moved in so if he wanted it he should have said something before he moved in. I personally felt he was unreasonable however he got his wishes.

My sister became a landlord and agreed with the tenant to give a very low rent on condition they (the tenant) did all minor repairs and decorating. However when the repairs needed doing my sister still had to fork out. It seems there is no such thing as a gentleman's agreement! Or woman as both were female.

This is always a problem with a rented house. It's the reasonable interaction between owner, letting agent, and tenant.

 

[JohnW2]

Indeed - which is why I said that if a designer does something a little 'unconventional' like that, they really should leave behind a detailed description of how they arrived at their design.

The point is in this case the information should be left with the home owner, and when that owner is not the occupier then it should be passed to the person doing the EICR at the time of ordering the work...

Definitely. Of course, there is always the possibility that the person undertaking the EICR will not agree with 'the explanation' provided by the designer - but, without that insight into the designer's thinking, the person undertaking the EICR does not have the opportunity to decide whether (s)he agrees or not.

Kind Regards, John

 

[ban-all-sheds]

he would need to turn the mains water off to check the bonding.

Gonads.

if it hadn't been given, SHE was breaking the law!

Ditto.

 

[ban-all-sheds]

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.

 

[EFLImpudence]

If you have a ring final

Is a spur subject to the same limitations?

you may only use it to supply BS 1363 accessories.

Are you of the belief that BS1363 FCUs are the only additional fusing method allowed on a ring and/or spur?

 

[stillp]

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

We've had this one before too. BAS, please tell us where the word "only" appears in that context.

 

[deadshort]

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.

100% in agreement with you BAS.

DS

 

[ban-all-sheds]

We've had this one before too. BAS, please tell us where the word "only" appears in that context.

We have, and we will keep on having it until people stop refusing to read.

I don't have to show where it says "only".

You have to show where it describes which circuit arrangements are exempt from 433.1.1 other than ring finals supplying accessories to BS 1363.