main bonding

Discussion in 'Electricians' Talk' started by sparksgalore, Feb 26, 2006.

  1. sparksgalore

    sparksgalore Member

    recently went to a friends house who had just had his extension wired and asked to see the test sheets to compare with my own the electrician had filled in minor works for the lights and the sockets even though the lights are wired from the board he also put in the comments that the main bonding was only 6mm ,is this ok because i thought the bonding should have been upgraded and a completion cert for the lights.
     
  2. Ripped Off

    Ripped Off New Member

    This is OK as long as this was the earth that was already in the premises. Goes down as a Cat 2 defect
     
  3. masterseal

    masterseal New Member

    Depend's what type of supply if PME/TN-C-S then need's to be upgraded to 10mm, if TN-S you would need to use your judgement and state on cert reasons for leaving as 6mm.

    Personally i would change it anyway for my own piece of mind.
     
  4. sparksgalore

    sparksgalore Member

    thanks for the replies but shouldn't the lighting definitely go on a completion cert.
     
  5. masterseal

    masterseal New Member

    Yes definitley need's to be on an EIC if a new circuit, minor work's only for extending circuit's
     
  6. rutspark

    rutspark New Member

    i thought the bonding should
    have been upgraded and a completion cert for the
    lights.

    If the customer does'nt want it doing (extra cost) I've started just noting on the cert that you've explained it needs an upgrade. Its down to the customer then

    Needs full eic for light circuit though
     
  7. Lokkars Daisy

    Lokkars Daisy New Member

    Depend's what type of supply if PME/TN-C-S then
    need's to be upgraded to 10mm, if TN-S you would need
    to use your judgement and state on cert reasons for
    leaving as 6mm.

    Personally i would change it anyway for my own piece
    of mind.


    Sorry Masterseal ,but keep to the facts , if it is PME then also use your judgement ,it is often not necessary to change a 6mm to a 10mm
     
  8. masterseal

    masterseal New Member

    Depend's what type of supply if PME/TN-C-S then
    need's to be upgraded to 10mm, if TN-S you would
    need
    to use your judgement and state on cert reasons
    for
    leaving as 6mm.

    Personally i would change it anyway for my own
    piece
    of mind.


    Sorry Masterseal ,but keep to the facts , if it is
    PME then also use your judgement ,it is often not
    necessary to change a 6mm to a 10mm

    542-02-01 Except where PME conditions apply, a main equipotential bonding conductor shall have a cross- sectional area not less than half the cross-sectional area required for the earthing conductor of the installation and not less than 6.0mm The cross-sectional area need not exceed 25mm if the bonding conductor is of copper or a cross-sectional area affording equivalent conductance in other metals.

    Where PME conditions apply, the main equipotential bonding conductor shall be selected in accordance with the neutral conductor of the supply and table 54H.

    From table 54H

    Supply neutral conductor 35mm or less Minimum copper equivalent CSA of the main equipotential bonding conductor 10mm.

    Note 547-02-01 Clearly states except where PME conditions apply

    How's this for fact Daisy ;)
     
  9. masterseal

    masterseal New Member

    Should read 547-02-01
     
  10. nottsspark

    nottsspark New Member

    hes right, minimum equipotential conductor size should be 10mm when PME
     
  11. Ripped Off

    Ripped Off New Member

    Electricians guide to the building regs has this down as a Cat 4 fault ~ does not comply to BS7671. No requirement to replace though
     
  12. masterseal

    masterseal New Member

    I know this is what you would put if doing a PIR Ripped Off, but if you carrying out any additions or alterations surely you would need to upgrade to 10mm on PME supply?
     
  13. Ripped Off

    Ripped Off New Member

    Took this up with the ODPM & IEE. The answer is if it was OK before you started work and you did not touch it then it still stands albeit with a defect. You cant fail an installation because regs have moved on.
    Just think in a couple of month we wil have new colours as a standard, does that mean all installations with red & black conductors are wrong and need to be ripped out
     
  14. masterseal

    masterseal New Member

    I understand that, but PME has alway's required 10mm as far as i know, i must admit though that i only started out from the red issue of the 16th so i might be proven otherwise. And i've seen PME installations from circa 1993 that have had 6mm installed they would have been subject to 16th ed,
     
  15. nottsspark

    nottsspark New Member

    like ripped off sez, it does require 10mm ideally but comes down as a number 4, as we will have to start doing when the new colours come into force
     
  16. masterseal

    masterseal New Member

    Nottspark i thought you also said that it should be 10mm?

    Like i said when doing a PIR i would put this down as non compliance with BS7671, my argument is would you feel happy leaving it if carrying out additions or alteration?
     
  17. nottsspark

    nottsspark New Member

    no masterseal i would always recommend upgrading but if the customer doesnt want it wat can you do. it usually happens when the leccy board replace an old cut out with a pme terminal and reconnect the main earth, thats why it often isnt 10mm even tho it should be when tncs. ive tested 2 houses 2day like that, just put it down on pir as a number 2, ze was good so even tho its not to regs its also nowt to worry bout
     
  18. DUMBSPARKY

    DUMBSPARKY New Member

    IF, you leave 6mm in, you will have to take into account over-current device and length, of main bonding conductor and wether the conductor is protected thermally!
     
  19. Ripped Off

    Ripped Off New Member

    Does changing a light fitting or replacing new socket faceplate warrant an upgrade in earthing or a full rewire.
    Need to assess whats been done.
    Guide it says no.
     
  20. nottsspark

    nottsspark New Member

    i was only doing a pir so just reported but i agree if you are to work on the installation u shud upgrade
     

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