Cable sizing

[RBS]

Need a cable to run approx 100m from incoming supply to a new build house,cable will be buried under ground what is the mimimum size cable that could be used to make it comply with the regs? Copper/aluminium? Thanks

 

[trev]

Hoist by my own pettard

 

[GLENNSPARK]

Damn you Glenn, you just pee'd on my fireworks
Bloody good point there mate I should have thought of that

well i can assure you that wasn`t the intention Trev:angel_smile: but i dont see why if they demand one thing....they cant see to the other n all.....its like movin the goalposts or summat innit....

 

[trev]

I know it wasn't the intention Glenn but you got me fair and square and you're right about them moving the goalposts as and when it suits them.
What was that line from Father Ted a few years back?
Oh yeah I remember now, Shower of B..........

 

[GLENNSPARK]

you are of course quite righ in saying that this work needs to be carried out in a correct manner though Trev....and i would also be inclined to discourage a `do it yourself` approach....

 

[plugsandsparks]

The only way i could think of to reduce the cost is to dig the trench yourself, they might accept that bit but if you want a proper metered supply with a bill and all, i.e. a property you can sell then i expect the power company will want to splice into their supply and provide the appropriate cable and fuse for the new property. It is their right

 

[Engineer54]

For them to approve a supply run like this, they would probably want the cable run in a concrete covered duct at 600mm depth, and would want to inspect it before back-filling!! Also if you were supplying the cable as well, would probably want to be present during the cable pulling, (all at your cost)!! lol!!

 

[Geordie Spark]

I worked on a new build 4 bed detached a couple of years ago. It was set back about 20 metres from the road and one trench was dug from the street to the house.

Into that trench went the gas supply - yellow Alkathene pipe run inside yellow plastic duct, water supply - blue Alkathene pipe and the electricity supply - split concentric cable.

All three services in the same 700mm deep trench resting on and surrounded by pea gravel before being back filled.

 

[a1guvner]

The only contestable element would be ground works or containment within your boundry

 

[Amp David]

Barn has been dropped and permission has been granted to build a 4 bedroom house,and the nearest point of supply is approx 100m away, around 6k to have cable laid by supplier so was thinking surely that it would be cheaper to buy cable and lay it and let them connect up????

If only it was a simple as that.

The supply you want to utilise, is it the old one for the barn or for something else.

 

[ABerry82]

i have been asked to install a garage unit in a outbuilding they wanted a couple of sockets and lights and i think i allowed about 20A total output. what size cable do you think bearing in mind its a 90 meter run in a trench from house to out building.

 

[DPG]

get ready for it..... daz

 

[Engineer54]

I worked on a new build 4 bed detached a couple of years ago. It was set back about 20 metres from the road and one trench was dug from the street to the house.

Into that trench went the gas supply - yellow Alkathene pipe run inside yellow plastic duct, water supply - blue Alkathene pipe and the electricity supply - split concentric cable.

All three services in the same 700mm deep trench resting on and surrounded by pea gravel before being back filled.

Pea gravel is not suitable to surround and compact around any type of direct buried cable, especially not with non-armoured concentric cable, ...Full Stop!! Cable in a suitable duct with a compacted surround of pea gravel you can get away with!!!... Cables should preferably always be laid on a soft sand bed and surrounded by compacted soft sand. At the very least, a bed of sifted soil and sifted compacted soil backfill....

 

[Geordie Spark]

Pea gravel is not suitable to surround and compact around any type of direct buried cable, especially not with non-armoured concentric cable, ...Full Stop!! Cable in a suitable duct with a compacted surround of pea gravel you can get away with!!!... Cables should preferably always be laid on a soft sand bed and surrounded by compacted soft sand. At the very least, a bed of sifted soil and sifted compacted soil backfill....

Be that as it may, that's what the contractors working for the DNO used !!

The trench was dug by the bloke who was building the house - it was a self-build - for himself, the contractor working for the gas supplier laid the gas pipe in it, the contractor working for the water supplier laid the water pipe in it, then the contractor working for the DNO laid the cable in it & covered the whole lot with pea gravel which they brought on a lorry. There was no sand - soft or otherwise - anywhere in sight.

After that, the bloke who dug the trench back filled it.

I have to say I was a bit dubious about the whole thing, but who am I to argue with the experts ??

In the end, my contribution to the project - which was the wiring, plumbing & heating installation - was all up to scratch, and that's all I was worried about.