The cable that runs from my house to my garage is run in 2.5mm T&E

Discussion in 'Electricians' Talk' started by scoz, Nov 28, 2017.

  1. scoz

    scoz New Member

    The cable that runs from my house to my garage is run in 2.5mm T&E. To replace this with 4mm SWA cable does it require notification.
     
  2. seneca

    seneca Screwfix Select

    No it doesn't because it's not a new circuit, it's just replacement of an existing (damaged!) cable. (it should take the same route however)
     
  3. scoz

    scoz New Member

     
  4. scoz

    scoz New Member

    Thanks for that
     
  5. retiredsparks

    retiredsparks Super Member

    As long as its like for like....has always been my understanding ?
    RS
     
  6. seneca

    seneca Screwfix Select

    No RS, I think "like for like" has gone out of fashion a bit now, although it's a different type of cable it's still not a new circuit so therefore not notifiable.
     
  7. spinlondon

    spinlondon Screwfix Select

    Not sure ‘like for like’ has ever been in fashion.
    The term ‘like for like’ is mentioned twice in both the 2000 and 2010 versions of the Approved document.
    Both times relate to inspection & testing and the issuing of certification.
    Basically stating that certificates should be issued for all work (notifiable and non-notifiable), except for the “simplest of like-for-like replacements”.
     
  8. retiredsparks

    retiredsparks Super Member

    What's wrong with 2.5 to shed anyway ?
    why is he changing it.... increased load.... calculations ?
    why bigger......
    Was the first install correct anyway ?... RCD'ed.
    The circuit characteristics have changed.... and is not 'the simplest of like for like'......
    Any further thoughts...?
    RS
     
  9. Bob Rathbone

    Bob Rathbone Screwfix Select

    Run another 2.5 SWA in parallel if the existing is not damaged, could be a cheaper option.
     
  10. Pollowick

    Pollowick Screwfix Select

    Could be like my neighbours garage - ordinary 2.5 T&E buried less than 150mm down and at times just under the surface.
     
    KIAB likes this.
  11. retiredsparks

    retiredsparks Super Member

    Yes , could be....good point.
    maybe more info from the op ?
    RS
     
  12. scoz

    scoz New Member

    I’m considering using a larger arc welder that will pull up to 30A
     
  13. seneca

    seneca Screwfix Select

    Just put a 4mm Swa in, 30/32amp fuse, job done!
     
  14. Dr Bodgit

    Dr Bodgit Super Member

    How long is this run of cable? 4mm might not be enough for 30A if its a long run.
     
  15. scoz

    scoz New Member

    25 metres
     
  16. Dr Bodgit

    Dr Bodgit Super Member

    Did a quick check in TLC voltage drop calculator, maximum current for 4mm SWA is 33 Amps, so its marginal.
     
  17. scoz

    scoz New Member

    The max is 30A but will only for a few minutes at a time
     
  18. KIAB

    KIAB Super Member

    6mm SWA.
     
    Dr Bodgit likes this.
  19. scoz

    scoz New Member

    Looking at Quickbit electrical suppliers they give 4mm swa as 49A and 6mm swa as 62A. What gives?
     
  20. Dr Bodgit

    Dr Bodgit Super Member

    There are a lot of factors that dictate maximum current capacity...type of cable, how its mounted, where its mounted etc. Those figures are likely maximum in best conditions, play around with this https://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html or better still, ask a qualified spark to spec the cable. 6mm SWA should be fine IMHO per KIAB.

    Whilst this is replacing an existing circuit, its no longer like-for-like so may be notifiable...?
     

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