Opinions needed please re: PIR i've just done

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S60TEM

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Basically.....

Student let upstairs flat with 5 bedrooms, living room, kitchen, 1x8.5kw shower.....various fans in toilets TV's in most rooms etc to give you an idea of current demand.

TN-S earthing arrangement.

WYLEX 10 way board, 5x 6A circuits, 2x20A radials, 1x32A Ring, 1x32A Shower, 1x spare. Single RCD 63A 30mA for latter circuits.

Ze = 0.13 Very good imo!! Double checked approx 10 times as the head looked like TNC-S but proved it wasn't.

This is where it got sticky for me........I'm awaiting a response from NAPIT technical about this also.

DB is fed via SWA 16mm 2 core.

LIVE conductor is one of the 16mm cores

EARTH conductor is one of the 16mm cores

NEUTRAL "conductor" has been made up of 7x 1.5mm PVC singles in black!

Now I know that the 16mm LIVE will take approx 80A using the reference method etc but what do you guys think of the NEUTRAL setup?

1.5mm using the same reference method can take a maximum of 20A so in parallel they could potentially take approx 7x20A = 140A which would be sufficient?

I just don't like the setup at all.

This is the second 5 year PIR on the property and there has never been any problems in approximately 10 years etc.....the previous PIR was carried out by Cityworks @ Newcastle Council who passed it 5 years ago.

Give me your opinions please as i'm tempted to advise changing them to a 16mm Neutral but the landlord is saying the obvious "Its been alright for over 10 years" etc etc

Still awaiting callback from NAPIT also bad day explode

cheers

 
7x 1.5 = 10.5mm

thats not the same size as the live. Dont think its a good idea to multipy 1.5 CCCap by 7.

I dont like it and would fail it, but I would honestly struggle to give a real clear answer why!

could you not use the earth 16m as neutral, then use the armour as earth? maybe with the crazy 7 cable setup as earth also?

 
I can do tomoro if it would help as I'm testing 7 of his properties at the minute, all in the same street.

I have not wasted my time completing this one until I recieve a definitive answer from NAPIT etc so havn't delved deeper.........yet!

He's doing my head in! LOL

 
Is this not a sub-main from below?

If yes then nowt to do with DNO.

If not and meters upstairs then just call them to check it out.

Is it split concentric cable?

 
7x 1.5 = 10.5mmthats not the same size as the live. Dont think its a good idea to multipy 1.5 CCCap by 7.

I dont like it and would fail it, but I would honestly struggle to give a real clear answer why!

could you not use the earth 16m as neutral, then use the armour as earth? maybe with the crazy 7 cable setup as earth also?
Thats the problem I have too, struggling for a reason why to fail it! Can't just say because I don't like it as the landlord will drop me as his spark etc so need to do the right thing but be seen to be helping him out too if you know what I mean. Thats why I've contacted NAPIT as then if they say FAIL, I can tell him that's the score!

Call in the DNO.AndyGuinness
you know aswell as I do that they'll do FA and if they did, they'd take months and charge the landlord a fortune which he'll then blame me for..........NO WIN situation.

 
Is this not a sub-main from below?If yes then nowt to do with DNO.

If not and meters upstairs then just call them to check it out.

Is it split concentric cable?
Yes mate think it might be concentric cable but its terminated and stripped back that tightly I cannot tell and the meter cupboard door downstairs is approx 18inches x 12inches and i'm 6'4" and 15 stone so access is a little dificult! LOL

 
because it is a flat, is this a direct feed from the supply company or is it fed from a main intake, and that the flat is using a sub feed?

headbang

 
mains are split into 2 x isolators and they then feed each flat seperately via sub mains.

 
So surely if its a sub main its nowt to do with DNO?

are the meters with the isolators or within the flats?

 
I have not read through the whole thread, but the supply cable you describe to the individual flats sounds like split con, the size of line and neutral cables will be the same. It is however normal to have a separate earth.

 
I have not read through the whole thread, but the supply cable you describe to the individual flats sounds like split con, the size of line and neutral cables will be the same. It is however normal to have a separate earth.
split con only has 1 large conductor - the neutral & earth are stranded, so if he does have a 16mm live and 16mm earth, but 7x smaller conductors for neutral, then it cant be SWA. unless its straight con, with separate earth?

isnt there a reg that states all live conductors should be in the same ferrous containment or something like that (i.e the neutral cannot be outside the SWA if the live is in it)

 
Yes; I believe that the neutral conductor must be (at least) the size of the phase / line / live conductor.

I follow up on a previous comment - why can`t you have the cores as L/N; and the armour as earth, with the black wire nonsense as belt-and-braces earth if need be?

 
isnt there a reg that states all live conductors should be in the same ferrous containment or something like that (i.e the neutral cannot be outside the SWA if the live is in it)
Yes.

 
Update,

went back today and basically stripped out the DB as it was wired soooo messy you couldn't see what the supply cable was originally and as some of you guys said, it is deffo split con cable. Not the best setup but NAPIT technical advised that it was OK but just make an observation on the report and mark the DB for future reference.

Thanks for all the input guys.

Scott.

 

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