moving the consumer unit.

Discussion in 'Electricians' Talk' started by st.clair, May 2, 2010.

  1. st.clair

    st.clair New Member

    at the moment the cu is in the basement next to the main fuse, but thats 10m away from the top of the stairs. if there is a problem it can be difficult to get to. will it be okay to put 25mm tails on and move it to the top of the stairs and do i need to put an isolator by the main fuse.
     
  2. seneca2

    seneca2 New Member

    Switched fuse required I think.
     
  3. JP.

    JP. Screwfix Select

    Concur with Sen..don't forget discrimination OP..or is that all a load of rubbish? Example if the cutout is 100 Amps then the switchfuse would be 80 Amps..is this discriminatory fusing factor still needed?
     
  4. JP.

    JP. Screwfix Select

    Although appreciate away from fuse discrimination then 80 (or even below that in some rare cases) could be indicated.
     
  5. X

    X New Member

  6. JP.

    JP. Screwfix Select

    Evening X..hows things going M8?
     
  7. st.clair

    st.clair New Member

    JP found one to do the job but to i fit it closer to the DNO or the CU. X good idea i will be fitting that as well never thought of that one,was going to use torch.
     
  8. seneca2

    seneca2 New Member

    Put switch fuse at supply end of tails to protect them.
     
  9. JP.

    JP. Screwfix Select

    Hi St Clair. Here is a picture of an EM light in my intake cupboard (cupboard under the stairs) The switch defeats the supply which turns it on (also handy for testing)..nowt else to say on the matter really, but may help.
     
  10. JP.

    JP. Screwfix Select

  11. Coloumb

    Coloumb Screwfix Select

    JP discrimation should be roughly half the upstream protection, ie 100a would be 50a etc..
     
  12. Coloumb

    Coloumb Screwfix Select

    I recently moved a cu on a 60a cut out. Used 10m SWA (OP Don't use tails unless they are surface mounted all the way). Put in an isolator but didn't bother with a switch fuse as after working out the Zs it seemed pointless to have a 60a cut out in line with a 60a switch fuse. How is that going to make anything any safer?
     
  13. JP.

    JP. Screwfix Select

    Many thanks for the enlightenment Mr C.
     
  14. seneca2

    seneca2 New Member

    But the switch fuse over 3 metres is a dno requirement isn't it Col?
     
  15. Coloumb

    Coloumb Screwfix Select

    Well, you know what, I tried doing some extensive research on this, rang the DNO, surfed like **** but as far as I can tell there doesn't appear to be any actual requirement under law to do this, so I didn't. It just seemed totally pointless.
     
  16. Removed 4

    Removed 4 New Member

    During my very long employment with LEB & EEB, the only requirement was for a DP isolator without the need for such a silly downgrade of the service fuse.

    Something has gone wrong somewhere........


    Lucia.
     
  17. seneca2

    seneca2 New Member

    It just seemed totally pointless.
    ------------

    I agree Col, it's a bit like exporting tncs earth, difficult to find definitive answers!
     
  18. JP.

    JP. Screwfix Select

    Maybe its because instead of 25mm tails people are using 16mm, thus necessitating the use of a switchfuse? This is with respect to a 100 Amp cutout ,and a run over what 3 meters.
     
  19. JP.

    JP. Screwfix Select

    PSCC..;)
     
  20. Coloumb

    Coloumb Screwfix Select

    JP, I do recall I did the maths and even with the given figures in 7671 guidence I recall the run could be about 50m before you had problems so long as the right sized swa was used.
     

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