RCD selection

Discussion in 'Apprentice Talk' started by Always learning, Mar 21, 2019.

  1. Always learning

    Always learning New Member

    Hi there,
    I'm an apprentice electrician and looking for some help/advice. I want to rewire my parents house. 3 bedrooms, 2 living rooms, 1 kitchen, 1 utility and 1 bathroom. Approx 2 double sockets in each room except bathroom obviously and a few extra in kitchen and utility. Standard pendant light in each room. No electric shower. Has immersion and electric oven. I can wire sockets, lights etc and consumer unit but my question is how to select RCD size. I purchased a consumer unit fully populated. 100a main switch and dual RCD, both 80a and multiple mcbs. I'm in Ireland and have only seen 63a or lower in domestic. Is 80a to large. I work for a large electrical company with multiple people so advice is hard got because you never work with anyone interested. Just a lot of fed up electricians. Help would be much appreciated.
     
  2. Peterdevon

    Peterdevon Active Member

    Use rcbos
     
    rogerk101 likes this.
  3. rogerk101

    rogerk101 Well-Known Member

    I agree. If I were wiring from scratch there's no question ... RCBOs throughout. The best thing about it is you know immediately exactly which circuit has a fault because it's the only one that is tripped.
     
  4. Always learning

    Always learning New Member

    I looked at that, but was looking at RCD, MCB etc route cause I was given a brand new populated unit from a cancelled job. Trying to stick to this route cause money is tight as an apprentice and wanna do it for free for parents rather than them having to buy bits for the job.
     
  5. spirits are real 2016

    spirits are real 2016 Active Member

    no 80a is not too big bigger the better than you can't overload it who will be doing the testing and certification.
     
  6. Always learning

    Always learning New Member

    Will have to try and talk nice to some of my workmates when its done. Just wanna have it done right so when the time comes they don't see a load of problems with my work. I was afraid if RCD didn't have enough circuits/load it might be a problem. 63a and 80a are the same price. Why would you put in a 63a then?
     
  7. spirits are real 2016

    spirits are real 2016 Active Member

    normally the only difference is the printing on the label and i know that for a fact I've seen the biggest electrical company do it on there main switch had the same internals just different label printed but i would put 80A then it would allow for future growth say higher rated shower in the future or if they moved one day. Plus what you could do is arrange the circuits downstairs sockets, upstairs lighting on one rcd and so on plus cooker on different rcd to downstairs sockets so if circuit tripped you would still have power and my favourite is having two way switching on stairs so you can turn the hall light on from upstairs so you don't have to go down stairs in the dark in the winter or you think you hear a noise down stairs during the night and have to investigate. Hope this helps.
     
    Last edited: Mar 21, 2019
  8. Always learning

    Always learning New Member

    There's only gonna be a few circuits for now and like you said maybe more in the future, but should I put all on the one RCD or use both. Is it better to keep the load high/low or does it matter. Thanks
     
  9. spirits are real 2016

    spirits are real 2016 Active Member

    don't put all on one rcd split the load upstairs sockets on one and downstairs on the other and split the lighting circuits on the rcd so your not left in darkness if one should Tripp its always better to split the loads then just use one.
     
  10. spirits are real 2016

    spirits are real 2016 Active Member

    what you should do is fit two double sockets side by side behind where the TV would go saves on having trailing extension leads tucked up at the back unless the TV is wall mounted.
     
  11. Always learning

    Always learning New Member

    Sounds good, was thinking along those lines but my lack of knowledge on RCD or sizing of which just made me doubt how to do it. Thanks for the help and advice
     
  12. dobbie

    dobbie Well-Known Member

    Read your copy of the on site guide regarding amount of recommended sockets.
    What does your tradesman have to say on the matters of rcd's?
     
  13. spirits are real 2016

    spirits are real 2016 Active Member

    i will always give help and advice were i can I've got 42 years of experience to full back on and done everything domestic that your about to incounter and much more.
     
  14. Always learning

    Always learning New Member

    Thanks again, I know it can be frustrating working with apprentices but I think some people don't really show you much, just leave it to be learned in a class room or let you try and piece it together yourself. My experience at least. Nice to do something like this rewire myself, but nice to know you have a bit of backup if required
     
  15. Always learning

    Always learning New Member

    Sorry only say other message now. Do you mean amount of sockets per circuit/MCB. I know some things vary from UK to Ireland. Need to check for sure but think it could be 10 sockets per circuit recommended. Not much to say on RCDs, fits 63a as far as I can see, don't know if that's recommended or just convenient to source off the shelf or old school methods
     
  16. Peterdevon

    Peterdevon Active Member

    It is not the number of sockets per circuit it is the floor area the circuit covers. Ring up to 100²m radials 50²m
     
  17. Always learning

    Always learning New Member

    I know what you mean now, I'd say the entire floor area would be 70-80 sq metres max. I haven't seen any ring circuits done. As far as I know, ring circuits aren't really recommended/allowed here anymore
     
  18. Sparkielev

    Sparkielev Well-Known Member

    Radial circuits best way to go either 4mm or 2.5mm better for testing and if the DB is large enough I would radial each bedroom maybe ring the kitchen depending on size
     
  19. dobbie

    dobbie Well-Known Member

    Why do you not ask the tradesman,who is teaching you and will know the regulations in Ireland?
     
  20. Always learning

    Always learning New Member

    Yeah, I have 12 mcbs do can do mostly radials. Prob do in 2.5mm, not much power gonna be drawn on any of the sockets really
     

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