New supply to Pigsty

[chris_k]

Got a job involving new supply to an old piggery+ shed next door. The building is solid block wall, no dpc, new roof, watertight. Its 35m from house cu. TNCS supply.
It will be boarded out at a later date.

New to the domestic game, so just a few questions-

Was gonna run 10mm SWA from house cu to piggery metal cu (fitting swa glands to plastic boxes not nice!) .Connecting to earth at house cu + stake at piggery. I know you shouldnt export pme earth but have seen this method mentioned before to give excellent zs .....
Then onto shed with 10mm swa to 2way cu.
or
6mm swa and just stake at piggery (quite dry free draining soil though!)

Inside, T&E clipped direct, conduit / trunking seems a bit of a waste as it will be boarded up soon.
Plastic backboxes to avoid corrosion

Your thoughts??

 

[ian.settle1]

What load have you got at pigsty?

10mm may be to small when you take the volt drop into consideration.

 

[chris_k]

Only 3x 4ft florry, 10x double sockets. No machinery, just storage, workspace.
Oh yeah, protected by 20a mcb

 

[ElectricMick]

Hi,
Just done similar to a garage (45M) to a 2 way cu and 10mm SWA sounds a bit excessive. I tried to attach a cable calculator but file was too big, but according to that 4mm SWA would be plenty. Voltage drop ok and if its protected by 20a mcb should be no problem at all.

Chris,
Did the cable calc for drawing 4Kw - that is all you would need for 20mcb. At 5Kw it goes up to 6mm so it is borderline. If you want me to email you the calc program I will. For some reason it will not let me attach, although it is small enough.

 

[chris_k]

Yeah 10mm is big. Client wants to futureproof if. (his wife wants a sauna at a later date)

 

[ElectricMick]

Chris, 10mm SWA will take 15 Kw. Don't know what sort of draw the sauna would have on it but 6mm will take 8 Kw. They're not going to do all that on a 20 A mcb? As I said, I can email you the cable calculator, it does everything from T+E to SWA. It gives you the rating and voltage drop at the touch of a button. Saves alot of grief (and money) putting in cable you could hang the Titanic from that may never be needed at its full potential.