Old electrical switch gear.

Discussion in 'Electricians' Talk' started by peter palmer, Jul 12, 2018.

  1. peter palmer

    peter palmer Well-Known Member

    Been to look at a job today that we are doing, it the same one as my fire alarm post. Like a dick I forgot to take photos which would have made things a lot clearer but the job is 150 miles away and we had a day to spec it so we were rushing.

    9 flats, 5 upstairs and 4 downstairs, it looks like the 4 bottom flats were re-wired a few years ago, red and black but plastic wylex RCD units so not that long ago, a mains upgrade and new socket fronts / LED lighting will be fine in those.

    However the consumer units have had new submains run to them in 16mm T&E, and a pound coin meter fitted, they have just bolted the T&E to the old 3 phase bus bar system like this. with a 60A SW/fuse inline in the communal cupboard.

    https://www.cef.co.uk/catalogue/products/46108-100a-1830mm-width-busbar-chamber

    We are removing the pound coin meters, so the only meter point is the DNO poly-phase incoming meter. The supply goes something like this - 3 phase head - meter - main isolator - 3 phase RCD - bus bar chamber and then to various submains and isolators for things like fire alarm and heating etc.

    I was going to rip the lot out and just put some Henley blocks after the meter to wire the 9 new flat isolators to plus a communal board, the T&E sub mains are in trunking so no need for any RCD protection on them.

    The upstairs flats are a total bodge and need totally redoing with new sub mains and total re-wires, does this sound the best approach with Henleys then tails into the SW/fuses, for the distribution. I know I could fit a Bemco type unit but there is a cost factor, the developer just thought he could change sockets and switches everywhere.
     
  2. dobbie

    dobbie Well-Known Member

    Do they not want each flat metered?
     
  3. peter palmer

    peter palmer Well-Known Member

    No, its an assisted living place, just self contained apartments, one owner - the pound coin meters were landlord owned anyway.
     
  4. dobbie

    dobbie Well-Known Member

    If not fitting a ryfield board, I would keep the busbar to feed the switch fuses.
    The switch fuses would all be mounted on the trunking,a load of Henleys would look really rough.
     
  5. peter palmer

    peter palmer Well-Known Member

    Could do, if re-using the bus bar chamber the main isolator will have to stay so would you keep the main RCD inline as well otherwise it will mean re-tailing everything. Not sure what the rating is of it, its very old though, it does work as it goes with a right clunk when the test button is pressed.
     
  6. Magicspark

    Magicspark Member

    Having an RCD serving 9 flats is a stupid idea.
     
  7. peter palmer

    peter palmer Well-Known Member

    A lot of installs have one though, the modern type are adjustable. Not sure if this one is a "S" type, what was the technology like in the 70s. I will get some pictures on Monday.
     
  8. Magicspark

    Magicspark Member

    Not serving 9 self contained flats they don't. Adjustable? Are you sure you are not looking at an MCCB?
     
  9. seneca

    seneca Screwfix Select

    Do you really want to take on a job with so much potential grief Pete, especially 150 miles away!
     
  10. peter palmer

    peter palmer Well-Known Member

    I'd rather sit in my garden than do any work at all but this client has masses and masses of work all over the Country, all expenses paid, its a good laugh with the other trades as well, **** ups most nights.

    Meant to add to this, its not a difficult job, the complex is empty, the loft is empty, just basic re-wires. Its a 12 week project, we are well capable of doing the job if we get some sort of spec to go off. I think the price we put in was £14 or £15K, not including the fire alarm so its not **** money either.
     
    Last edited: Jul 12, 2018
    KIAB and seneca like this.
  11. peter palmer

    peter palmer Well-Known Member

    Maybe, I wonder why it was fitted at all then, it wan't to protect the newer submains, its part of the original switch gear, maybe it was some new fangeled idea that cost the original developer a shed load of money.
     
  12. dobbie

    dobbie Well-Known Member

    You will need to check it out Peter,you do not want an RCD up front of nine flats and the landlords.
     
  13. Lectrician

    Lectrician Screwfix Select

    A 4 way MCCB board would be best. 12 outgoing single phase circuits. No need for upfront RCD if earthing arrangement ok.
     
  14. peter palmer

    peter palmer Well-Known Member

    Is that not a bit pricey though LEC? I would imagine each MCCB is £60 or so and that's without the panel. You can get a Wylex SW/fuse for that and there is already 4 x SW/fuse's there already on the newer submains, albeit the older style like this.

    [​IMG]
     
  15. Lectrician

    Lectrician Screwfix Select

    It would be more expensive, but in my opinion, the best method. There are many ways to do a job, but I always prefer to go with the best option if possible, even if more expensive. I guess I am lucky that most of my customers take the same sort of view.
     
    Magicspark likes this.
  16. Bob Rathbone

    Bob Rathbone Well-Known Member

    The last flat job I did from a 3 phase service, I fitted a DB with a single phase breaker for each flat service, RCD protection was provided locally in each flat.
    The busbar chamber is OTT for a domestic installation, take it out and put it on E Bay.
     
  17. dobbie

    dobbie Well-Known Member

    If each flat was getting metred, rather than just one meter the dno would probably insist on a Ryfeld board.
     
  18. Magicspark

    Magicspark Member

    That's sounds poor imo as there is little to no discrimination.
     
  19. Bob Rathbone

    Bob Rathbone Well-Known Member

    The DNO have little control over what the customer installs provided that it complies with regulations and building regs.
     
  20. Bob Rathbone

    Bob Rathbone Well-Known Member

    A 50A breaker for each flat with 10mm t&e to a small CCU, one bedroom flat, cooker, water heater, sockets and lights. Never had any call back due to CB tripping before local protection operating, and it was 10+ years ago. Cable adequately protected and voltage drop under control. Each flat was fitted with a pre payment meter next to the CCU in the flat.
     

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