RCD's, MCB's and RCBO's

Discussion in 'Electricians' Talk' started by RolandK, Aug 9, 2018 at 7:30 PM.

  1. RolandK

    RolandK Active Member

    Hi
    Just looking for some clarification on what I should currently have in my CU.
    At the moment it's a split load unit with 2 RCD's and MCB's. Should I be considering getting it upgraded to RCBO's? Also where the heck do AFDD's fit in? Or leave it as is?
    Cheers
     
  2. Bazza-spark

    Bazza-spark Well-Known Member

    If you are not having any issues with nuisance tripping I wouldn't bother changing to RCBO's as your current setup looks ok.

    AFDD's are pretty new in the UK and are supposed to detect arc current in switching devices. They have been used in other countries with degrees of success. However as I understand it, the ones that are available take up a slot in your CU so you would double the size of the CU if you fit them on every circuit.

    No doubt at some point they will become mandatory, but at the moment they are new and few people understand them.

    Time will reveal all.

    Kind regards.
     
  3. unphased

    unphased Screwfix Select

    Agree with Bazza. There is no need to update a CU just because new devices become available. Basic protection for circuits has always been short circuit and overload, both handled by fuses or mcbs. IMPROVED protection to include earth faults introduced RCDs, and now AFDDs and SPDs are becoming more prominent with the advent of 18th edition. Please don't fall in to the trap of thinking you must update your CU to include these. Leave that to the cowboys to mislead the populace.
     
  4. RolandK

    RolandK Active Member

    Thanks both.
    Just like to keep up with stuff! I took a look at the AFDD's and can see CU's becoming a metre long or double deckered!
    I don't have any issues with my current setup so will take heed of what you say and hang on to my hard earned!
    Cheers
     
  5. Bazza-spark

    Bazza-spark Well-Known Member

    Like RCBO's have incorporated MCB's and RCD's in time I am sure they will incorporate AFDD's.

    Wait and see what the market does and how the scam providers push things, we are still in knee jerk territory at the moment. It is too early yet and many sparks (including me) haven't completed the training. I do have the book, and have read the public for comment version. Have many reservations so let's sit it out a while. I am sure there will be an addendum to follow.

    Kind regards
     
  6. RolandK

    RolandK Active Member

    From a 'non profesionals' viewpoint I've been looking Ed. 18 and other bits out of interest and it's mind boggling! Was in Spain the other week looking at a socket just by the hand basin I was using. Also the washing machine installed in the bathroom and thinking do many more people die of electrocution there than over here with our more stringent practices. Not saying we should go backwards but where will it end?
    Cheers
     
  7. Sparkielev

    Sparkielev Well-Known Member

    Its all very well bringing out the new amendments and AFDDS but as long as the electrical world stays unregulated it wont mean nothing, people still go to BQ and the like and buy any amount of stuff and do carp work
     
  8. Rulland

    Rulland Well-Known Member

    I would be interested in seeing comparisons between countries that have supposedly less stringent regulations to be honest.
    I was in Greece earlier in the year, and the wiring was diabolical, or so it would seem from a BS7671 point of view, BUT, is it actually causing major problems?, or extra deaths?.
    In this country we seem to be going down the route of putting all these safety measures and extra cost in place to prevent accidental death by electrocution etc.
    Does it work?, are we safer in this country because of the regs, I'm quite interested, genuinely, as to whether what we have to adhere to, that other countries obviously don't, has much impact.
    Thoughts forum members please.
     
  9. Mr A greig

    Mr A greig New Member

    Pretty soon we'll think back to the good old days when the power going out ment a fault with your wiring or appliance instead of a fault with your "safety" features.
    When things just work people leave them alone, when they stop working they feel inclined to start poking about with a screwdriver.
     
  10. RolandK

    RolandK Active Member

    There's a cost issue here too. Many people attempt their own electrical work in ignorance or deliberate avoidance of the correct procedures. Whatever the reason cost is often an issue and the increasing complexity of the regulations and the systems to which they relate will only prove to be counter productive in the search for safer and safer systems. Those costs are ultimately borne by the consumers. Not just the direct costs of materials and labour but the indirect costs of the documentation, training and equipment borne by the professionals providing those services. Not to mention the host of official and non official bodies existing to dream up and monitor the regulations.
    I saw some statistics comparing the incidence of electrical fires between the EU, USA and Japan. For the first 2 the figures were in their thousands for Japan it was 12! What are Japanese doing so right?
     
  11. unphased

    unphased Screwfix Select

    Thats so true, Roland. I was only mulling this over the other day after yet another hard day at work. I came to the conclusion that the electrical industry is filled with Union mentality. In fact it is all based around a Union. The JIB. When you examine all the different bodies that are supposed to regulate it it all falls in to a Union structure. Its a Union in all but name. The requirement to join one of the bodies or you dont fit in. On top of all that we have this diabolical regular issue and amendment of the wiring regulations. I really don't know why we can't just freeze the Regs as they stand. They are good enough, safe enough and do the job. The reason, as we all suspect, is to generate revenue from book sales for the industry as a whole. It is such a corrupt trade. I can't blame people for having a go themselves and avoiding all the corruption that surrounds the professional side of it. DIY has a lot going for it. There are many good DIYers out there who can do a better job than some of the pros.
     
  12. Pollowick

    Pollowick Well-Known Member


    You need to split the Regulations away from the implementation - Part P, registered bodies/schemes and such.

    The regulations define what is safe/unsafe. It is the installation, regulations and registration that is "unionised" and a near closed shop. I know of a very well qualified electrical engineer who did his own house wiring but had real problems getting it signed off. The LA sent an "inspector round" who tried to fail it on several points - none of which were anything like a failure. And he made comments about "bad design" as the CU had a bank of RCBOs protecting specific circuits, or that there was a ring of RCBO protected outdoor sockets - "much better to spur of the house ring" and more.
     
  13. Mr A greig

    Mr A greig New Member

    How could that be construed as bad design?
    I know that this will be contrary to most people's feelings, but I think it should be easier to do your own work and get it checked while it's all still visible. At the end of the day some people are always going to do things themselves and if it's double checked rather than kept a secret there would probably be far fewer hazards out there.
     
    RolandK likes this.
  14. RolandK

    RolandK Active Member

    Begs the question do any LA inspectors actually have practical on hands experience!? Even I know that one was talking b*****ks.
     
  15. RolandK

    RolandK Active Member

    I used to have a local experienced and qualified sparks who worked in the 'real world'. He would pop round before any work was done and see what was needed and how to do it. He was the happy for me to do the first fix laying cables and fitting back boxes etc. So long as he could see all cable runs and check it was all ok then he'd connect it all up and test it. I used to do more of my own electrical work some years ago but nowadays I want a piece of paper to say the work is ok so I have no hassle come sale time. Fortunately I can afford but many can't.
     
  16. Pollowick

    Pollowick Well-Known Member

    He was apparently an electrical contractor employed by the LA ...

    Another which I could not initially believe, the Live:Earth (R1:R2) and Neutral:Earth (R1:Rn) resistance ratios were the same as each other but both were wrong on a 2.5mm ring. He had failed to note that it was wired with 1mm CPC which, at the time of installation, was standard. And when his failing was pointed out, tried to insist it was replaced.
     
  17. RolandK

    RolandK Active Member

    How did it all finish up? Did you have to replace anything due to this bozo?
     
  18. Pollowick

    Pollowick Well-Known Member

    No, he did not replace anything. Except one twin socket which had failed for some reason.
     
  19. RolandK

    RolandK Active Member

    So he went off with his tail between his legs!
     
  20. seneca

    seneca Screwfix Select

    Agreed UP, that's why i'm pulling out of the "scam", apart from their 550 quid fee they'll also want me to do an 18th. course. It could have just been done as 17th. amendment 4 couldn't it.
     

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