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Obvious departures from the regulations at first glance at a new consumer unit.

Jaymack
I was asked to give an EICR on an domestic property which is to be placed on the market (part P applicable). I found that a builder as part of the other renovation work, (new doors, windows and kitchen etc.) has carried out the installation of a new metal consumer unit. On first opening this dual RCD unit, the 2 lighting circuits were on one R.C.D., and the 2 final ring circuits on the other R.C.D,, it was obvious also, that some wires to the new CB's were short and not lengthened, resulting in a bird's nest at the M.C.B.''s.


Plainly, a qualified electrician hadn't carried out the work. What would the readers as registered electricians have done ?. 1. Walk away. 2. Propose to have an E.I.C.R. carried out (UNSATISFACTORY), then carry out the rectification work and issue MWC's.3. Rectify the obvious departures, issue M.W.C.'s and then issue a SATISFACTORY E.I.C.R. 


Jaymack
  • 0

    AJJewsbury:




    I prefer to make an installation as safe as is possible, staggering circuits across RCD's is commonsense to achieve this, is paramount IMO.



    In which case twin RCD CUs are out - all RCBOs would be the only option.

     




    Nit picking, the post is about dual RCDs

    .

    Jaymack.
  • 0
    You can compromise and have a couple of RCBOs in a dual RCD consumer unit, that’s what I have at home.


    Andy Betteridge
  • 0

    Sparkingchip:

    You can compromise and have a couple of RCBOs in a dual RCD consumer unit, that’s what I have at home.

     



    Nit picking once again!


    Jaymack
  • 0
    The less circuits you want to be unusable when a RCD trips the more RCDs you need to fit.


    One upfront RCD takes everything out, a RCBO on a circuit only takes that circuit out, anything in-between is a compromise between cost and the integrity of the installation.


    You pays your money and takes your choice.


    Andy Betteridge
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    Yes if a twin RCD unit then I put 2 or 3 RCBOs in as well, cooker, shower, boiler usuallyand say the RCD split sensibly between sockets Area A, Lights Area B and vice versa usually. Although all RCBOs is my favourite. Myself I`ve a front end one RCD and never really been a problem (steam iron overfill or kettle fault being rare but slight problems)
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    Sparkingchip:

    The less circuits you want to be unusable when a RCD trips the more RCDs you need to fit.


    Andy Betteridge   




     

    Obviously. ? 


    Jaymack
  • 0
    Try pegging the precise requirement down to determine exactly how  many RCDs are required in a typical domestic installation.


    Andy Betteridge
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    Sparkingchip:

    However there’s no specific regulations regarding the ordering of devices in a consumer unit, it’s just convention to put the largest protective device next to the main switch

    Andy Betteridge 




     

    Depends on the training. As an apprentice for 5 years no less, in the Scottish steel industry.many moons ago; as a basic design feature, the ratings of equipment for connecting to busbars, was decided according to their Amp rating in order to minimise I²R losses, this was a basic design feature whether mickey mouse CU's or larger distribution equipment.


    Jaymack
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    So if a shower or appliance  circuit is added to a domestic consumer unit should the whole CU be stripped to move the protective devices along to position the new protective device next yo the main switch or can it go after the existing lighting circuits.


    I think we all generally line the CPDs up in descending order starting at the main switch, but in reality I’m sure that’s custom and practice rather than out of necessity.


    I did the electrical work in a kitchen for a High Court judge some years ago and his wife passed comment that he had spotted that I had all the accessory screws stood to an attention, I know how to be an anorak and apparently he likes anorak wearers to work in his home. but I know that some installation details don’t really make a difference. Actually the screws could be slightly over tightened or slightly loose to get them all lining up, if you used a torque screwdriver they would not line up.


    In a domestic installation what are the chances of a MCB or RCD protecting a lighting circuit with all LED lights ever tripping without some external influence? The days of a light bulb or lamp blowing and taking out a fuse or MCB are numbered.


     Andy Betteridge
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    Sparkingchip:

    I have installed economy seven consumer units with alternate ways left empty to allow the MCBs to run cooler.


    Andy Betteridge 




     

    A holier than thou and a cavalier attitude. Being economy 7, there would be long periods of no activity on MCB's. 1. How would the overall I²t losses, be affected with that arrangement?. 2. Would the maker concur with that arrangement as being necessary?. 3. Would the customer be paying for your design. 4. Would you advocate that arrangement for all C.U.'s. 5. Would you advocate others to follow suit. and the bottom line for dollars and sense - 6. Would it make you competitive? ?

    Jaymack

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