Size of SWA to run to garage

[JamesHughes]

Hi all,

been trying to find some figures for this, and need confirmation..

Have a run of about 15m from my outside junction box to my garage for three phase/4 core SWA. Will be required to run: lights, usual garage sockets, 15A compressor (Currently run off 13amp circuit - to be rewired), and three phase lathe and milling machine.

Not all at the same time!

The 3 phase kit usually runs of a three phase convertor, off a 13amp plug, that gives an indication of ampage. I don't run both at same - only one pair of hands...same with compressor - too noisy to work while thats running.

I reckon 4mm2 XLPE cable should be sufficient - giving me about 40amps total.

Is that about right?

TIA

James

 

[JamesHughes]

Oops, forgot to ask, how deep should the SWA be buried - it will not enter the house at all, just run from the box where supply and meters are, alongside the house, underground to the garage. I could fix it to side of house and only run underground for about 1m to reach the garage, but would prefer to get it out of the way.

It will be under driveway gravel for entire length - no gardening/digging involved.

Cheers

James

 

[flyingsparks]

just run from the box where supply and meters are

What are you going to be connecting the SWA into? There shouldnt be any kind of distribution boards / switch fuses in the meter box.

I take it you have a 3phase supply to your house then??

SWA should be buried 600mm deep on a bed of sand and sand on top of this. Then use bury warning tape too.

are there any incoming services into the garage? water? gas? oil? structural steel?

4mm is a bit small i'd say. Prob best doing it with at least 6mm or even 10mm.

 

[ban-all-sheds]

It will be under driveway gravel for entire length - no gardening/digging involved.

You've got 450mm+ of gravel on your drive?

Don't cars sink into it?

 

[flyingsparks]

It will be under driveway gravel for entire length - no gardening/digging involved.

You've got 450mm+ of gravel on your drive?

Don't cars sink into it?

Didnt spot that!

 

[JamesHughes]

Pretty sure you got what I meant, but to be clear, because its a driveway, I am not expecting to be digging it up or gardening in it!!

Thanks for info so far.

Yes, I do have three phase to the house, I was hoping (?) that the the SWA could be plumbed in just after the meter where the currently redundant Eco7 meter sits - that can be removed as now oil fired. Plenty of room in the box on outside of the house for this sort of thing if its allowed.I would of course get the leccy people in to do that side of the plumbing - not something I would wish to do myself (and I don't think you are allowed to?)

No other services to garage - brick built, wooden flat roof.

James

 

[ban-all-sheds]

Pretty sure you got what I meant, but to be clear, because its a driveway, I am not expecting to be digging it up or gardening in it!!

But someone might in the future, when they decide to get rid of the gravel and have block paving.

And honestly, I did think you meant you wouldn't need to dig, just put it below the level of the gravel.

 

[chkee]

I just bought 20 metres of LSF 4 core 25mm SWA and now not going to be using I will end up either putting it on eBay or taking it to local scrap merchants for weighing in as just the copper is probably worth more now than when I bought it ! - cost about £200 , I am in London and it would be too heavy to post - I would be happy to let you have it for £100 Cash on Collectiom

 

[JamesHughes]

And honestly, I did think you meant you wouldn't need to dig, just put it below the level of the gravel.

Yeah, having re-read - it was a tad unclear!!! But I see your point, someone may want to dig there later.

James

 

[JamesHughes]

I just bought 20 metres of LSF 4 core 25mm SWA and now not going to be using I will end up either putting it on eBay or taking it to local scrap merchants for weighing in as just the copper is probably worth more now than when I bought it ! - cost about £200 , I am in London and it would be too heavy to post - I would be happy to let you have it for £100 Cash on Collectiom

I'm afraid I am up nr Kings Lynn, so its a bit of a trek!! Thanks for the offer though.

James