Power to shed

[PCAnimal]

Its probably been asked lots! I've got the idea of using 40mm pipe or Armour cable underground.
However the main power line would be far easier to get outside if I could run the cable down the external wall from the roof. I have got a spare mains cable in the loft which is not serving anything at present (used to do electrical shower until it was removed).

Are you allowed to run it down the wall and if so what should I cover it with? trunking?

 

[ban-all-sheds]

Its probably been asked lots! I've got the idea of using 40mm pipe or Armour cable underground.

The latter.

I have got a spare mains cable in the loft which is not serving anything at present (used to do electrical shower until it was removed)

RCD protected? MCB rating? Size?

What do you plan to do in the shed?

Are you allowed to run it down the wall and if so what should I cover it with? trunking?

Don't use it outside - joint it to the SWA inside the loft and run that down the wall.

• 
  
  
  
• //www.diynot.com/wiki/electrics:books
  
  
• //www.diynot.com/wiki/electrics:mcbtocable
  
  
• http://www.tlc-direct.co.uk/Book/4.3.1.htm (all subsections)
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/cableselection_web.pdf
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  
  
• http://www.tlc-direct.co.uk/Book/5.3.1.htm
  
  
• //www.diynot.com/wiki/electrics:mcb2
  
  
• http://www.tlc-direct.co.uk/Book/7.13.3.htm
  
  
• http://www.tlc-direct.co.uk/Book/8.1.1.htm <-- VERY IMPORTANT
  
  
• //www.diynot.com/wiki/electrics:swa-gland
  
  
• http://electrical.theiet.org/wiring-matters/16/elect-inst-outdoors.cfm?type=pdf
  
  

 

[PrenticeBoyofDerry]

Are you allowed to run it down the wall and if so what should I cover it with? trunking?

Providing the cable is adequately protected for external and environmental influences yes it would be allowed.
But as BAS has posted the logical step would be to joint the SWA to the existing cable in the loft, using an adaptable box.
Prior to making this connection, I would check that this circuit is safe and suitable for continued use.
If using SWA cable external of the building this must be fitted to a secure structure (that does not include fencing) or routed overhead or underground.
(there are permitted minimum heights and depths, that must be complied to)
You would also need to calculate the load required in shed and any voltage drop over the distance the cable is run, to assess cable sizing and fuse rating required.
RCD protection would be required on at least the part of the new circuit within the shed, if using SWA as distribution externally.

 

[bernardgreen]

When digging a trench for SWA it is just as much hard work to lay in two ducts. The extra expense of the duct is a small price for the extra peace of mind. One duct to pull the SWA into and one for other circuits such as phone, door bell repeater, alarm and data cables to be install as and when you find you need them.

 

[dhutch]

All good advice I think.

My understanding from looking at this myself is that you cant add a new circuit [without notification], but you can extend and old on as you preposed. Equally, you cannot DIY outdoor wiring[without notification], but if you join the SWA inside the house, and the other end inside the shed, that is then allowable.

If the shed is made of non-combustable material and under 25m^2 you can then do pretty much anything you like in it, if its wood, your more limited.

There is then the topic of exporting the earth of PME supplied building. And if the shed is metalic, the issue of if you should bond that to earth or not.

NB, Im not an electrician.


Daniel

 

[JohnW2]

My understanding from looking at this myself is that you cant add a new circuit, but you can extend and old on as you preposed. Equally, you cannot DIY outdoor wiring, but if you join the SWA inside the house, and the other end inside the shed, that is then allowable.

Anyone, if competent, can do anything - I presume you are talking about what can be done without notification. Did the need for notifying outdoor wiring (wiring of outdoor power and lighting installations) not disappear with the April 6th changes - which left very little notifiable (primarily just bathrooms and 'new CUs', IIRC).

Kind Regards, John

 

[maltaron]

I think the new Part P allows DIY outdoor wiring, but not if it requires a new circuit.

 

[dhutch]

[quote="JohnW2";p="2755572]
Anyone, if competent, can do anything - I presume you are talking about what can be done without notification. [/quote]
Yes indeed, post edited for clarification.

Did the need for notifying outdoor wiring (wiring of outdoor power and lighting installations) not disappear with the April 6th changes - which left very little notifiable (primarily just bathrooms and 'new CUs', IIRC).

If im honest, I wouldnt know.

Although it would still be advisable to make the joins inside if at all possable.


Daniel

 

[JohnW2]

Anyone, if competent, can do anything - I presume you are talking about what can be done without notification.

Yes indeed, post edited for clarification.

Thanks

Did the need for notifying outdoor wiring (wiring of outdoor power and lighting installations) not disappear with the April 6th changes - which left very little notifiable (primarily just bathrooms and 'new CUs', IIRC).

If im honest, I wouldnt know.

I've just checked, and I was more-or-less right. The one other thing (which I knew but forgot to mention) was the installation of a new cicuit.

There are hence only three things now notifiable - installation of a new circuit (which may be subject to interpretation and 'wriggling'!), installation of a 'new CU' and work additions/alterations in a 'special location' (primarily bathrooms).

[Although it would still be advisable to make the joins inside if at all possable.

No argument with that.

Kind Regards, John

 

[dhutch]

...and work additions/alterations in a 'special location' (primarily bathrooms).

And kitchens?

 

[EFLImpudence]

Nope.

http://www.legislation.gov.uk/uksi/2012/3119/regulation/6/made

 

[JohnW2]

...and work additions/alterations in a 'special location' (primarily bathrooms).

And kitchens?

Nope, kitchens aren't 'special locations'. The only special locations of normal domestic relevance are within the 'zones' of a bathroom, or in a room containing a swimming pool or sauna.

As I said, notfication has almost 'gone'.

Kind Regards, John

 

[securespark]

Not quite there with bathrooms:

It is only notifiable if inside a zone.

 

[JohnW2]

Not quite there with bathrooms: It is only notifiable if inside a zone.

Indeed, but that's what I said:

The only special locations of normal domestic relevance are within the 'zones' of a bathroom, or in a room containing a swimming pool or sauna.

Kind Regards, John

 

[JohnW2]

As I said, notfication has almost 'gone'.

I might have added that one effect of this might be to largely kill the market for very expensive 'old colours' T&E. Whilst, in the past, some people will have been trying to argue that electrical work was undertaken prior to 1st Jan 2005, as time moves on, they will be progressively trying to argue that the work was undertaken after 5th April 2013. 'New circuits' might be the main exception to this, although I imagine that it would very often be difficult/impossible to establish whether a circuit was 'new' or not!

Kind Regards, John