Running a new SWA to supply a shed

[Helm-Electric]

Running a 4mm SWA to the shed, approx distance is 20m. Earthing is PME.

I plan to run the 4mm SWA out from the wall of the house and cleat it along the side until it reaches the back of the house. From there the cable will go to ground at a depth of 450mm all the way to the shed. I plan to fit a 2 way CU for lights and a double socket within the SHED. The SWA will be protected by 30mA RCD and MCCB at the CU within the house. Total load shall not exceed 2kW. The installation will be inspected and tested by qualified electrician who also happens to be my friend. I am making it easier for him by doing all the grunt work...

I am guessing there is no height restriction for the SWA?

Thanks

 

[a1guvner]

I just thoughts of the dreaded exported earth thread .................... rearing it's ugly head

With a dash of V-phase?

 

[malcolmsanford]

With a dash of V-phase?

I've also got your hat as well ...................................

 

[Helm-Electric]

What is wrong with exporting the earth from a PME system? The earth loop impedance will still be within the required value. Or are you thinking about circulating currents if both ends of the SWA is earthed?

Thanks.

 

[a1guvner]

Sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .sorry sorry .

 

[IQ Electrical]

Phew, that was a close one!

 

[a1guvner]

Phew, that was a close one!

lol.......

 

[Helm-Electric]

Well I take it exporting PME is fine, as there are no extraneous-conductive-parts, and if the shed is all wooden (insulating), then a perfectly adequate equipotential zone can be constructed using just the cpc and so it doesn't seem any more hazardous then using PME inside a house[FONT=Arial, Helvetica, sans-serif]. [/FONT]

 

[IQ Electrical]

Well I take it exporting PME is fine, as there are no extraneous-conductive-parts, and if the shed is all wooden (insulating), then a perfectly adequate equipotential zone can be constructed using just the cpc and so it doesn't seem any more hazardous then using PME inside a house[FONT=Arial, Helvetica, sans-serif]. [/FONT]

Absolutely and where there are extraneous-conductive parts, the zone can still be extended but that cpc would have to be sized to meet the requirements of a main protective bonding conductor too.

 

[Helm-Electric]

Thanks IQ. No metal frame in shed. Just out of curiousity, what do you with a CEW system? Just continue the earth through in the same scenario?

 

[Helm-Electric]

The other half was asking if the cable could just be under the stone chuckies when going along the side of the house (she doesnt like the idea of cable along the wall - aesthetics and all that) before going to 500mm when it reaches the backgarden. My initial thought is no its not acceptable, but I might as well ask the question and I can feed that back to her!

Or I volunteer her to do all the digging if she really wants it underground all the way

 

[a1guvner]

Bring the spade round,,,,,,,,,,,,,,,,,,,,,

 

[Guitarist]

How about running it inside 32mm white waste pipe along the side of the building? She may find that less intrusive than black swa. Just a thought

 

[Helm-Electric]

How about running it inside 32mm white waste pipe along the side of the building? She may find that less intrusive than black swa. Just a thought

I have got black polypipe already.. so will this suffice? I want to do it properly, no short cuts.

Below is how I think I may be able to connect the SWA without disrupting the wooden paneling that my current house CU is on. Basically, the tails get split from the meter via a new 2 way CU with RCD.

 

[malcolmsanford]

You won't need 25mm tails for the 2 way CU if they are under 3mts

 

[Helm-Electric]

It is under 3m. 16mm suffice? Overall, no quams with the above idea? The shed end wouldnt have a RCD as it would rely on the RCD back on the new 2 way CU in the garage.