Attention Sparkies - Help Needed, RE Power to outbuildings / sheds

[greatoldone]

Hi chaps,

I'm building a shed in the back garden to house my Lathe and other machine tools I plan on getting later on. Obviously this will all need power.

I need some advice on the best way to run the cabling to the shed.

Here's a rough, not to scale layout of the house and the sheds:



The main consumer unit is in the garage.

I'd rather not lift the paving, as it's been professionally laid and if I dig it up, it all look rubbish when I put it back down. I also would like to avoid going around the perimeter of the garden, as it'd cost a fortune in armoured cable.

My initial thought is it would be easier and cheaper to take a feed from the consumer unit out of the garage wall and then straight up to the loft, with the cable in some galvanized conduit. Then run the cable through the loft to the opposite wall and then down toward the sheds in more conduit, with the main feed ending up in the workshop and a separate small consumer unit there.

Here it would feed 4-5 double 13amp sockets and some fluorescent lighting, and some form of light in the shed down the side of the house.

What I need to know is would this be OK by the electrical regs?

I know this sort of thing is notifiable to the powers that be, so it would have to be signed off by a qualified professional - but how much of it can I do my self, and what needs to be left to the Sparkie?

I've tried researching this myself, but get lost with earthing methods, cable cross section, separate earths, Part P and voltage drops.

Other things - the Lathe is 1000w, 13amp. Any other machine tools would be of similar rating, but unlikely that they would be run at the same time. An outside socket on the wall of the workshop would be nice for the lawn mower.

Thanks In Advance,

Jason

[Starchaser]

Re: Attention Sparkies - Help Needed, RE Power to outbuildings / sheds

Not a sparks so just the way i did it,
To give you something to think about DONT FOLLOW, JUST IDEAS, when i wired my garage I went in to the fuse box via I think it wes 30 amp fuse that fed the emersion (n0 longer used) ( or a spare fuse) if you have one, I went through the wall and ran the cable ( electric cooker cable) on the outside of the house in conduit well above head height. availble B&Q
I run the cable from the house to the garage by stretching a steel cable between the house and garage and ran the cable through a suspended flexible conduit under the steel cable I then went into a fuse/distribution box in the garage, from which you can run circle mains to lights, sockets ect on their own fuses but keeping the max load/fuses to under 30 amp in total, I ran a seperate earth down to an earth stake in the ground direct from the RCB in the garage fuse box.

[cameronfurnival]

Re: Attention Sparkies - Help Needed, RE Power to outbuildings / sheds

Hi Jason, I had a similar job though not over the disance you and Starchaser are talking about. I was able to run all cables but the sparky made the connection to the main board. Had to sign a bit of paper iirc to say it was up to regs. I used plastic conduit. You can screw it to walls and stuff using saddle connectors. the circuits will have to be tested and approved or you wont be able to sell Goo Towers at a later date without remedial testing. A copy of the regulations is probably in the library if you are looking for some bedtime reading one day?

[CABRIOBOB]

Re: Attention Sparkies - Help Needed, RE Power to outbuildings / sheds

Hi Jason

When I wired my garage, I would advise a trip fuse box, 1 for the lights and 1 for the sockets. Then I would double wire the sockets, ie when you wire 1 socket then wire on to the next etc and at the last socket run a wire from the last socket direct back to the fuse box, so if you are using all the sockets at once you could get an over load and by fitting an extra wiring to last socket back to the fuse box it gives you max voltage and prevents the fuse box from triping.

A 2,5mm 3 core cable would be ok for the sockets and a 1.5 or 2mm cable would be ok for the lights.

Cheers

Bob

[Starchaser]

Re: Attention Sparkies - Help Needed, RE Power to outbuildings / sheds

Yes I agree when I said "circle" thats what I ment "ring" curcuits back into the fuse box

Cheers Bob