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Radial Circuit using box installation method...

Former Community Member
Former Community Member
I am curious if anyone has ever done this, and if not any reason?  Is it acceptable? 


So, the scenario is that you install a radial circuit for lighting or sockets for that matter (could apply to either in this instance), and the image I've attached as the example probably isn't the best, but it was the clearest image I could find. 


The example is as follows - you have a circuit coming from the CU on a 16amp radial, rather than just go from one to the other repeatedly could you not use a junction box installation method. As long as the box was accessible.  I know the image shows lighting etc, but I was not thinking of it like that in this instance, it would be either just lighting or just sockets. 

992563266d16340370be4f2ff3f68dde-huge-screenshot-2021-02-15-at-16.28.37.png1f339cb9468d38ac0d0749602b0dec82-huge-screenshot-2021-02-15-at-16.42.16.png


  • 0
    well for a socket circuit you might use 2.5 T & E and use a 16A or 20A MCB (or RCBO) and branch off in all directions or for a lighting circuit use 10A or 6A say in 1.5 or 1.0 T & E . Just as a starter for ten. in fact you could do away with the box and use a socket or a switch or even a ceiling rose as your first or only branch so long as cables and terminations permit being mechanically and electrically robust. Or similarly you can wire as "Tees" or branches, not that uncommon. Or just use "conventional" circuits if that is easier. The world is yer lobster

  • 0
    I would prefer to use non flammable junction boxes/enclosures rather than flammable plastic ones. But the system is do-able. We used to call it the junction box method.


    Z.
  • Former Community Member
    0 Former Community Member
    I did wonder, I know I posted before about the lighting and plugs on the same and some people don't like it. 


    I have seen the above image a few times in that form, usually with those junction boxes, I suppose that is something to considering being that they are plastic that is more flammable.  I also find those Schneider boxes a little strange as you can in theory pull the cable out unless you secure it before it goes in. 


  • 0
    What specifically are you concerned about in the suggested circuit arragnement?
  • 0
    Looks a bit like BS 7671 Fig 15B. Be aware that if you want to branch at a socket, the terminals of BS 1363 socket-outlets are not required to accept more than 8 mm² of conductor although the better ones will accept 12 mm².
  • 0
    Chris Pearson:

    Looks a bit like BS 7671 Fig 15B. Be aware that if you want to branch at a socket, the terminals of BS 1363 socket-outlets are not required to accept more than 8 mm² of conductor although the better ones will accept 12 mm².


    And the photo looks like somebody's college practical work on a board.


    Z.


  • 0
    Most electricians avoid installing junction boxes​​​​​, particularly those that can only be accessed by clambering around in lofts looking for the boxes under the insulation, and those that involve lifting floors and floor coverings.


    Generally, junction boxes not should be needed or installed.


  • 0
    spacey:

    I did wonder, I know I posted before about the lighting and plugs on the same and some people don't like it. 




     


    I  think you mean lighting and SOCKETS or socket outlets on the same circuit, not plugs.


    Z.


  • Former Community Member
    0 Former Community Member
    Zoomup:
    Chris Pearson:

    Looks a bit like BS 7671 Fig 15B. Be aware that if you want to branch at a socket, the terminals of BS 1363 socket-outlets are not required to accept more than 8 mm² of conductor although the better ones will accept 12 mm².


    And the photo looks like somebody's college practical work on a board.


    Z.




    :) afraid not, the screen grab of the sockets etc are from a Legrand PDF - wasn't going to upload an entire catalogue! - the second is actually from a youtube video about something completely different but it was the best image I could find - if you want to watch it its here  - https://www.youtube.com/watch?v=IZs8PKWAHEo


  • 0
    Reg. 559.5.1.204 limits certain popular type lamp holders to a 16 Amp maximum protective device. That may restrict lighting circuits being fed from socket circuits.


    Z.

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