Cable size for showers

Discussion in 'Electricians' Talk' started by iandaviot, Feb 19, 2010.

  1. iandaviot

    iandaviot Member

    Assuming that cable is about 10-15m from fuse box and clipped direct in loft and walls what is the maximum size of shower you would fit on a 6mm cable. I normally say 8.5kw, any bigger and i use 10mm Does anyone else do other wise?
  2. 14th edition

    14th edition Well-Known Member

    Can't recall what the clipped direct rating is but 8.5 on 6mm with a 32/40 is fine.

  3. robster911

    robster911 New Member

    hi.. providing there is no insulation involved and the whole run is clipped direct or in free air..6mm and 40a mcb will be ok up to and including 8.5kw..any bigger and10mm is im sure you are aware there are many other factors that need to be considered when selecting size..but on average your 6mm is sufficient 4 most installs off this size..:)
  4. JP.

    JP. Screwfix Select

    Just auto whip a lump of 10mm in and be done with it. You will be glad you did..;)
  5. wally2

    wally2 New Member

    I try & stay clear of 10mm, Bit of a problem getting it into a pull switch at the same time as keeping the outer sheath in the box as well. I usually use 6mm for up to 8.5kw. It does not however allow for upgrading to a higher rated shower later on. I reckon 8.5 is enough power most of the time.
  6. JP.

    JP. Screwfix Select

    Those Crabtree 50 Amp DP have got nice terminals Wal.
  7. kangooman

    kangooman New Member

    Hi all,

    I thought that on 6mm a 32A breaker 7.2Kw would be your max size shower, using anything bigger would it not mean you would need to go to a 10mm cable and larger breaker?

    Appreciate other factors, insulation, grouping, clipped, distance etc.

  8. iandaviot

    iandaviot Member

    Thanks for your comments. Its just i am doing a shower replacement on Monday and its a 9kw that the customer has bought with only 6mm cable. It could be a total ***** to get 10mm in, so if i can get away with it would have left 6mm in. I normally will always use 10mm in a new install, it allows for upgrading later on.
  9. Removed 4

    Removed 4 New Member

    Don't worry about it Ian. Just use the existing 6mm cable for the 9kW shower. Your customer won't have the slightest problem with it - unless he's rich enough to spend all weekend in the shower.......

  10. seneca2

    seneca2 New Member

    As long as the cable isn't surrounded by insulation and not an excessively long run, 6mm will be fine on 9.5 Kw.
  11. JP.

    JP. Screwfix Select

    I don't belive that people would use 6mm for a shower unless it is pre-existing.

    Ok 2 or more years back yes..but now? No Way.
  12. JP.

    JP. Screwfix Select

    If I went back into re-furbs and stuff and had to stick cable in for a electric shower, then it would be 10mm and nowt less..:)
  13. mr sillys

    mr sillys New Member


    if it is not required seems a bit untrained to me


    put in the right gear at the time of installation

  14. JP.

    JP. Screwfix Select

    I've never fitted an electric shower Mr Sillys..but I sure as heck know whats indicated with these things M8.
  15. mr sillys

    mr sillys New Member

    lap dog if you do not know then shut the * UP


    gord bless him......

    [Edited by: admin]
  16. JP.

    JP. Screwfix Select

    I do know though Mr Sillys..;)

    I state again that in a new install then I would use 10mm. What other people do is there business..and they have there own modus operandi.

    Its no joke if a customer wants a more powerful electric shower after the install. What you going to say?..Sorry thats the max as the cable wont take it..try saying that to one of the Hampstead lot and see where you get.
  17. sinewave

    sinewave Screwfix Select

    try saying that to one of the Hampstead lot and see where you get.

    U don't frequent 'The Heath' do ya JP? :O
  18. unphased

    unphased Screwfix Select

    I might ask you to do the same silly *. You are such a bore.

    [Edited by: admin]
  19. mr sillys

    mr sillys New Member

    get some balls

    and say

    "you gets what you wanted change your mind you pay my time"

  20. unphased

    unphased Screwfix Select

    Such a bore.

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