Looking To Build Office Shed - Need Help With Electrics

[Jagz64]

Hi There

Looking to build an office shed but want some advice on the best
way to run a supply to the shed.

The CU is at the front of the house in the front room and the shed
will be in the garden.

The distance between the CU and Shed will be about 40-50 Meters.

The CU is Split Load RCD.

I was looking into running an SWA supply cable from the CU to the shed
but i wanted to know what the max distance is allowed.

Also I have a spare 2.5mm T&E which i runned not that long ago
in the kitchen with the new harmonized colours.

Is there any chance i could use the 2.5mm T&E to supply the shed. ?

Will only be using the shed for 2 computers, 1 server + lighting and
maybe a standard 3-pin plug heater.

Thanks, Jagz

 

[davelx]

No kettle, coffee machine? It's quite a walk back to the house in the pouring rain

What is a "standard" heater - 1kW, 2kW, 3kW?

 

[Jagz64]

Hahahahah i love it

Yeh going to need to add a kettle to the list aswell as a beer fridge and tv.

as for heater 1KW

oh and the distance between the house and shed is only 10meters or less.

 

[ban-all-sheds]

• //www.diynot.com/wiki/electrics:part-p
  
  
• //www.diynot.com/wiki/electrics:mcbtocable
  
  
• http://www.tlc-direct.co.uk/Book/4.3.1.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.theiet.org/publishing/wiring-regulations/mag/2005/16-elect-inst-outdoors.cfm?type=pdf
  
  
• http://www.tlc-direct.co.uk/Book/7.14.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/7.13.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://www.tlc-direct.co.uk/Book/5.3.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/6.1.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/8.1.1.htm
  

 

[HullMarc]

The distance between the CU and Shed will be about 40-50 Meters.

oh and the distance between the house and shed is only 10meters or less.

Your house is 30-40 meters long?

What sort of route are you planning on running the cable? What's your earthing system?

 

[Jagz64]

Not to sure mate i ain't measured the house lol...

I'm just guessing but for you i will measure it with my feet and
then get back to you on how long it is in feet loll.

its a terraced house in north london

we have an extension as well with a concrete floor so i will have to
Burry the SWA cable into the wall.

Not to sure how far in to the brick wall.

As regards to the earthing system i think its a TN-S system.

hope that helps.

I'm just looking to install 4 wall sockets and some spot lights.

and as for route please see the image.

Blue is SWA cable.

Thanks, Jag

Office Shed - SWA Route

• Jagz64
• 14 Jun 2010
• 1

 

[bongos]

Jag, your descriptions sound a little vague and confusing. I think your best bet here is getting some sparks in to offer quotes and finding out if you can do as much of the 'donkey work' as possible, to their requirements. This will help to save you money.

You wouldn't want to be chasing walls in your house for SWA either. It might get a bit messy.

How long did you decide the cable run was in the end?

 

[Chri5]

There's no reason why you can't use TE 4mm, 6mm or even 10mm in the internal run from CU to external breakout and change over to swa to cover element and mechanical protection.

You don't seem to have grasped that volt drop comes in to play and we need a fairly accurate distance assessment to offer advice on cable sizing.

You also need to confirm the load at the shed in watts / kw so the cable can be calculated for drop and installation method.

So come on stick your nose out and tell us what sized fuse / load you will need:-

10a = 2300w
20a = 4600 w
30a = 6900w

Be clear about the items in the shed, there's no point running something that trips daily, so assess the use of sockets and come back with the detail requested.

 

[Jagz64]

Thanks for the info guys.

I will get back to you with the correct details as to whats going to be
in the shed and also the correct measurements.

I want some overhead as well just incase as i don't want to be installing
more cables or changing cables.

Price is not an issue for me ... Safety is

Thanks, Jagz

 

[ban-all-sheds]

You don't seem to have grasped that volt drop comes in to play and we need a fairly accurate distance assessment to offer advice on cable sizing.

• 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/4.3.11.htm[/list][/QUOTE]

 

[SgtTrojan]

I thought shed advice was banned on here?

 

[ban-all-sheds]

Depends what you mean by "shed"...

 

[Taylortwocities]

Price is not an issue for me ... Safety is

Thanks, Jagz

In which case go to www.competentperson.co.uk and do a local search using your post code.

Problem solved!