1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Submain to an outbuilding, perhaps

Discussion in 'Electrics UK' started by ladiesman020, 5 Jan 2015.

  1. ladiesman020

    ladiesman020

    Joined:
    13 Apr 2014
    Messages:
    32
    Thanks Received:
    1
    Location:
    London
    Country:
    United Kingdom
    I've got a detached garage only 2.2 metres away from front of house with no electric. How would I go about sinking cable into the ground. What cable would I use (6.0mm t&e?) swa? Would I have the cable going from the main fuse box in the house to another fuse box into the garage.
    Ideas needed
     
  2. Sponsored Links
  3. winston1

    winston1

    Joined:
    11 Jan 2010
    Messages:
    7,197
    Thanks Received:
    555
    Location:
    London
    Country:
    United Kingdom
    This is an old thread you have dug up. However.
    To sink the cable in the ground you need a spade and pick axe.
    Use SWA cable, the size depends on the load in the garage.
    It can be run from a separate way on the house consumer unit assuming there is RCD protection. You don't necessarily need a consumer unit it the garage, sockets can be run direct and lights through a switched fused connection unit which you use as the light switch.
    If there is no RCD you will need to fit one at one end or other of the cable.

    But you can't do this yourself legally easily. Someone will be along shortly to tell you the full procedure and no doubt tell you to get a qualified sparks in.
     
  4. ladiesman020

    ladiesman020

    Joined:
    13 Apr 2014
    Messages:
    32
    Thanks Received:
    1
    Location:
    London
    Country:
    United Kingdom
    I was thinking about 1 500w floodlight, 4 100w lights and 6 sockets
     
  5. Taylortwocities

    Taylortwocities

    Joined:
    28 Jul 2006
    Messages:
    20,553
    Thanks Received:
    2,132
    Location:
    Oxfordshire
    Country:
    United Kingdom
    500watt floodlight???

    Are you trying to light up wembley stadium, or something?
     
  6. winston1

    winston1

    Joined:
    11 Jan 2010
    Messages:
    7,197
    Thanks Received:
    555
    Location:
    London
    Country:
    United Kingdom
    500 watt flood lights are no longer allowed. Use a 50 watt LED type. Likewise 100 watt lights ( if you mean light bulbs) are no longer available. In a garage fluorescent fittings would be better, say two 5 foot types.
    Are the sockets for a battery charger and drill etc or do you intend higher power devices? Heaters would be quite high power.
     
  7. ladiesman020

    ladiesman020

    Joined:
    13 Apr 2014
    Messages:
    32
    Thanks Received:
    1
    Location:
    London
    Country:
    United Kingdom
    Ok a 400w floodlight!!! 4 batten holders and 4-6 sockets for 12v car battery charger and 1300w mitre saw
    I was thinking of 6.0 t&e or swa in metal conduit underground would be enough
     
  8. Taylortwocities

    Taylortwocities

    Joined:
    28 Jul 2006
    Messages:
    20,553
    Thanks Received:
    2,132
    Location:
    Oxfordshire
    Country:
    United Kingdom
    No way, Jose!

    Building Regulations now have a 150W limit on external lighting.


    Read about it at http://www.planningportal.gov.uk/permission/commonprojects/lighting/

    In particular this bit|:


    External Lights

    If you are installing an external light which is supplied from your electrical system and fixed to the exterior surface of your house then you should ensure that reasonable provisions are made to enable effective control and/or use of energy efficient lamps. Two options for achieving this are:

    Installing a lamp with a capacity which does not exceed 150W per light fitting and the lighting automatically switches off both when there is enough daylight and also when it is not required at night
    Ensuring that the lighting fittings you use have sockets that can only be used with lamps having an energy efficacy greater than 40 lumens per circuit-watt.


    In any case, think about the running cost. (AND your effect on the ice cap) Allow £1 per year per watt.

    Use LED lighting.
     
  9. winston1

    winston1

    Joined:
    11 Jan 2010
    Messages:
    7,197
    Thanks Received:
    555
    Location:
    London
    Country:
    United Kingdom
    As I said earlier use SWA cable, not T & E. 6mm will be ample, even 2.5mm will be OK for your needs. You don't need conduit, SWA can be direct buried.

    Take it from a 20A MCB indoors (bearing in mind what I said about RCD protection).
     
  10. Sponsored Links
  11. Taylortwocities

    Taylortwocities

    Joined:
    28 Jul 2006
    Messages:
    20,553
    Thanks Received:
    2,132
    Location:
    Oxfordshire
    Country:
    United Kingdom
    Only 20A, Winston? XLPE 6mm² is better than that!
     
  12. ban-all-sheds

    ban-all-sheds

    Joined:
    27 Aug 2003
    Messages:
    69,782
    Thanks Received:
    2,858
    Location:
    London
    Country:
    United Kingdom
    Why?
     
  13. ladiesman020

    ladiesman020

    Joined:
    13 Apr 2014
    Messages:
    32
    Thanks Received:
    1
    Location:
    London
    Country:
    United Kingdom
    6.0 T&E cos I thought it would be more than enough for 1000w of lights and 6 double sockets.
    Would 4.0 be better?
    I was thinking of running T&E from CU to a junction box near where the cable goes outside/underground into SWA there its goes underground the 2.2m to the garage where it comes up to a CU in the garage
     
  14. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    48,650
    Thanks Received:
    3,191
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    That obviously would depend entirely on what you were planning to plug into those 6 double sockets - after all, if you plugged 3kW loads into each of those 12 outlets, you'd be talking about 36,000 watts (over 150A at 230V)!! You need to design on the basis of expected loads.

    Kind Regards, John
     
  15. ladiesman020

    ladiesman020

    Joined:
    13 Apr 2014
    Messages:
    32
    Thanks Received:
    1
    Location:
    London
    Country:
    United Kingdom
    So would 4.0 be better. I'm not using it much maybe a bit of lighting
     
  16. Taylortwocities

    Taylortwocities

    Joined:
    28 Jul 2006
    Messages:
    20,553
    Thanks Received:
    2,132
    Location:
    Oxfordshire
    Country:
    United Kingdom
    Geez

    FOUR pages of discussion and we still haven't determined the requirement for the current.

    The generally process is:

    Determine the load
    Select CPD
    Examine the installation requirement (method, environment, etc)
    Calculate volt drop
    Select the cable size

    (and there's more)

    Want to know how to do it? Here's a guide and example

    There is no room for "maybe I'll use size x" or "would size y be better" (or I wonder what I've got round the back of the shed/ on the van)..

    Its a calculation, with a result, not a guess.
     
    • Thanks Thanks x 2
  17. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    48,650
    Thanks Received:
    3,191
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    Not really - this present discussion started as a hijack at the bottom of page 3. However, that aside, I agree wholeheartedly with everything that you go on to say.

    Kind Regards, John
     
Loading...

Share This Page