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18th edition consumer unit codes

IronFreely
This is the first time I’ve posted since the forum migrated so HELLO EVERYONE!

Ive fitted many dozens of metal units since the 3rd amendment and I’ve carried a handful of maybe 5 EICR’s on new boards and so far I’ve lucked out because they’ve all been either perfect or so bad they simply needed pulling off and starting again.


I have always ensured that my units are as sealed up as possible even from the rear knockouts, I tend to stick one of those intumescent pads over the rear knockouts before pulling the cables in or squeeze a bit of intumescent sealant in the gap back there, and if the manufacturer requires an additional Earth bond between cover and box obviously I use what’s provided.

 Recently I’ve inspected a unit which has a nice big knockout at the back straight into the wall cavity, it’s big enough to very nearly squeeze my hand into the dry wall cavity... It also has had the cross bond between the box and the cover deliberately cut off (I’m guessing they did this because it was done up with Nylock and was difficult to undo). I’m just wondering what EICR classification codes others would give for these conditions? Personally I feel they don’t meet “manufacturers instructions” nor meet requirements for sealing arrangements (527.2) and may go for a C3 or C2... 


What say you people of the forum?
  • 0
    Tricky...

    nor meet requirements for sealing arrangements (527.2)



    What's the required fire resistance of the wall? Unless it's part of a fire compartment it's likely not to have any requirement for fire resistance at all - so leaving even a door sized hole isn't technically a problem.


    Likewise lacking IP2X protection isn't an issue if the cavity can't be directly accessed - from the other side of the wall say.


    I know where you're coming from - it doesn't make much sense to have a non-combustible enclosure if you leave great big holes in it - but the regs requirement isn't for the CU to be entirely fireproof - just that the material the enclosure is made from to be non-combustible - if that's done the letter of the regs are satisfied. All the intumescent seals etc are all very well and good, but not a regs requirement as such.


    As for lack of reliable earthing of the lid of the steel enclosure - presumably the manufacturers provided a link because the fixing screws either don't provide a sufficient path for possible fault currents or lack of reliable contact (e.g. due to painted surfaces) - check the instructions, but if they day it's always needed and is seems plausible that the internal wiring could come into contact with the lid then that that would seem a clear C2 to me.


       - Andy.
  • 0
    I agree that it comes down to what the manufacturers instructions say.

    I have not seen any manufacturers specify a requirement to fill any gaps or unused knockouts with intumescent material so I would not give that a code, unless of course the hole also meant that the CU didn't comply with the requirement to have IP2X and IP4X on the top surface.

    Some manufacturers supply a earth bond between cover and box so this should be fitted. If it is absent, I would code it C3 if there is metal to metal contact between the cover fixing screws and box. If the cover was not reliably connected to the earthed box, probably a C2 but I haven't seen one like that.

    I much prefer boards that don't need an earth bond, like Hager. It's OK fitting a board with an earth bond, like Lewden, but a right pain when working on them afterwards having the cover hanging in the way.


    Dave
  • 0
    I was writing while Andy was posting.

    Agree entirely.


    Dave
  • 0
    May be worth a look

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