Something missing from meter cupboard?

[ericmark]

Which 3m limit is that?

Your allowed 3 meters from the origin to over current device if there are no branches, I am sure it is to allow from buzz bar to enclosure in a switch room, but it does not say that, so if you for example have 2 x 2.5mm² terminating into say for example a socket supplied from a 32A supply then you could have a single 2.5mm² from that point to say a FCU as long as it is unlikely to get damaged. 433.2.2 I am sure many of us have exceeded that 3 meters where the supply fuse is not a great deal greater than the cable capacity, although technically a spur from a ring main comes under that limit, cable rated at 22A with a MCB at 32A it is unlikely if the cable damaged that the 32A MCB would not trip, as long of course that the loop impedance is low enough, however that is not the case with 300A buzz bars and a 6mm supply to a lighting distribution board. However there is nothing in the regulation which says this. So in theory an unfused spur from a ring, or a garage consumer unit fed to 6mm² from the 100A incoming DNO fuse would both be limited to 3 meters, even when we know with the 13A socket or with at 32A and 6A MCB it is very unlikely the cable will be over loaded other than through damage to the cable in which case as long as the loop impedance is within limits the protection device will open.

However today it does not seem to matter about common sense, if the regulations are breached then you may find it listed on an EICR, I remember one where the builder to finish the house had a load of 500W halogen lamps to dry off plaster, the cables went through door ways and some electrician had followed the Best Practice Guide and failed it. By time I arrived the builder had finished and taken all the lamps away, so there was nothing wrong with in installation, in fact there never had been, to me if your checking the installation then multi-adaptors plugged in as shown in Best Practice Guide are beyond your remit. OK unplug them, but to list as a failure is wrong.

However how do you work with common sense if the person is not trained, it may seem plain to us, but would it be plain to the first year apprentice? I have seen where some one has allowed something to happen as in that situation it was reasonable safe, but then the same thing has been repeated where it was not, and it's too easy when the installation is not in front of one to say yes that's OK but some has been missed. So I suppose for the forum one has to be super careful, we will get some one who will say "I checked on a forum and they said it was OK" when they have missed out something vital.

 

[EFLImpudence]

Eric will not accept that the 3m. rule only applies if the the relevant part of the circuit does not have fault protection as stated in 433.2.2(i).
If it does have fault protection per 433.2.2(i) then 433.2.2(ii) - the 3m. specification - doe not apply.

 

[ban-all-sheds]

433.2.2 (ii), I suspect

I didn't know that it had been determined for sure that the SWA would not have adequate fault protection.

 

[davelx]

I didn't know that it had been determined for sure that the SWA would not have adequate fault protection.

Neither did I - I simply stated that I suspected that that was the 3m he was referring to. I made no statement as to whether that reg was relevant or applicable in this case. Please don't read things into my posts that are not stated (hmm, that sounds familiar).

 

[ban-all-sheds]

Yup. Sorry.

 

[ban-all-sheds]

Which 3m limit is that?

Your allowed 3 meters from the origin to over current device if there are no branches

Eric - how do you know that the cable won't have adequate fault protection?

 

[zooankski]

The cable run is around 15 meters to the garage. I have attached a picture of what I have at the meter cupboard. Not sure what size SWA it is though as can't see any markings.
I will get a pic of the CU in the garage tomorrow.





The cable runs from the white cupboard on the house to the side of the left side of the garage. What I really want doing is the house end sorting and then a few more sockets in there as there are only 2.
I also need to ensure that I can use my kettle and a few other items the same time in there as I can never be bothered walking back inside!
Not worked out loading yet but I guess the average kettle must come in at 3kw?
I need to get some quotes in but would rather tell them what I want doing first.
I quite enjoy reading all your opinions. Coming from an electrical background (aircraft electrician and avionics engineer) I sometimes think I should have gone the sparky route!

 

[EFLImpudence]

Oh dear, something else missing.

 

[ban-all-sheds]

I'm guessing then if the SWA is just into the Henley's there's no gland on it/the armouring is not earthed?

There aren't/Let's hope their armours are earthed at their other ends.

 

[zooankski]

SWA is landed and earthed at the garage it appears. Is there a requirement for both ends? I just cannot see how this was signed off but one bit of investigation at a time. I will open the CU at the garage tomorrow to check that out. Is the switched fuse still the preferred option in the cupboard?

 

[TheKeymeister]

Looks like it was wired by a moron, officially now you've now got to get the DNO or supplier out to isolate as your garage is connected on before the isolator, rendering it pretty pointless as it can only isolate part of the load.

I'd also hazard a guess that if your main consumer unit is fed by SWA then there's a good chance that is also more than 3m away and should also be protected by something other than the cutout fuse...

If that is the case, the proper way of doing this would be to put a second meter box in, turn both SWAs into it, and either put a small distribution board or two switchfuses to feed the SWAs, fed from the isolator in the original meter box, with that isolator being fed directly from the right hand side of the meter.

 

[ban-all-sheds]

Looks like it was wired by a moron,

How hard would have been to have used a slightly larger metal enclosure for the switch, and gland the cables properly?

I'd also hazard a guess that if your main consumer unit is fed by SWA then there's a good chance that is also more than 3m away and should also be protected by something other than the cutout fuse...

Do DNOs require that if the cable is armoured?

I just cannot see how this was signed off

Because the person who did it signed off his own work.

 

[zooankski]

Gets worse! Just had a good look at the garage CU. SWA not earthed there either! Should there not be a tag that is connected to the earth rail in the CU? The other really odd thing is that I have a main earth that goes no where. It is just chopped off near floor level and there is no sign of where, if ever, it went. Saying that, I will have a better look tomorrow once I vacuum the area.The CU earth is reliant on the unprotected SWA earth as it stands although I am no expert by any means. Possibly was not needed as the house is supplied using TN-C-S?. Just fired off a few quotation requests. Would install of a switch fuse and SWA protection be do-able in a day? no idea what to expect on the quote front although I know I need to just bite the bullet and get it sorted, especially as I want 3 more sockets fitting in the garage and use of my kettle!





On the subject of switch fuses, The one mentioned earlier is massive! would something along these lines do the job?



Sparky might have some other brand suggestions but I know space in the meter cupboard is pretty limited and the one above is a fair bit smaller. Will he require supplier to pull the main fuse prior to fitting?

 

[zooankski]

Because the person who did it signed off his own work.

Makes sense and I am guessing I have no recourse even though I have a certificate? Probably not worth the paper it is written on! Only been in the house since October and had problem after problem so getting pretty down about it all now, especially as the building itself is really well constructed. It is almost like they just rushed the end.

 

[ericmark]

With the number of MCB's in that consumer unit you could in theory draw over the current for which the cable is rated. Likely earth cable was fitted ready to be connected to a water supply which has not then been brought into the garage, the earth is grey core of SWA, however it is clearly not correct.

The paper work should say who tested and inspected and what scheme provider he was using to self certify, so first is call person who did the work, second is call the scheme provider.