Cable Supply Size 1km

[Downham]

Hi there

I am looking to run a supply cable to a house in rural Italy, however, it's quite a distance from the pole to the property.

The distance is 1km, the supply is 230v, single phase, usage will be average... 8kwh?

My question is what size cable would I need? Would they need to be separate conductors, aluminium or copper etc.

Advice urgently needed please.

Many thanks

 

[pc1966]

The limiting factor is going to be voltage drop at maximum current. Realistically you will have to look at doing this at high voltage otherwise you are looking at an enormous cost and weight of cable. Seriously, think of £100k for cable alone for even 40A or so! (on-line calculator giving about 300mm^2 aluminium cable for that)

I don't know the Italian regulations but if you went for the highest "low voltage" option of just below 1kV then the ideal-case cable metal is reduced by almost 18 times but you have cost of transformers (and voltage drop, so actual cable size might be higher to compensate). Going to "high voltage" (1kV AC or above, here in the UK often 11kV) would make sense to further reduce the main feed cable size and cost, but often comes with significantly different regulations.

Typically the cable would be aluminium for this to keep cost down and lower risk of theft. Often overhead lines it is usually steel-cored for physical strength with 6 strands of aluminium around the core for the conductive aspect (aluminium is about 1.5 times less conductive than copper, steel about 8 time less than Cu).

Digging a 1km trench for buried armoured cable is an option, but you might find it cheaper to run between poles if the planning allows it and no issues of crossing roads/rivers/etc.

This is not a DIY sort of plan!

 

[Rockingit]

Yep, everything above. This is NOT a DIY job in any country. And, if it were me, I’d be asking the energy company to give a quote for a new supply.

 

[pc1966]

As above, ask the power utility for a quote. Unless it is way over £50k or stupidly long lead-times then just go that way.

There is a whole lot more to consider if 'DIY' such as way-leave for land route, planning permission, land use and acceptable burial depth (or clearance for overhead lines), etc. Not to mention the actual electrical work!

Recently I was involved in putting in 0.5km of duct for fibre broadband with 4 access chambers, not something I would repeat for anything short of a generous fee!