Hi
Just getting started with a view to DIY electrics on my house extension in a few months time, and ideally would like to map out the current circuits so I can plan the best way to join up, or where new circuits may be required etc.
2 Questions
I reckon I can do some DIY non-live testing of each ring main circuit, firstly establish which outlets are included on each ring main, then all that area of work (R1 + R2) / 4 etc etc to detect any faults on the ring or at the outlet; but can anyone point me in the direction of a method for working out what order the outlets sit on the ring? Or do you never really know until the floorboards are up? It occurs to me that you can do a long sequence of trial and error by disconnecting the outlets 2 at a time, then anything not working must sit between these two (or if everything else still works they must be adjacent), and slowly build a picture. Please, is there a method easier and quicker, perhaps with a multi-meter?
I read online that you can only have one spur per ring main, but I also read that if you only have two sets of wires at a socket, you can spur at this point without checking everywhere else - which infers one spur at any given point on a ring main (eg: 4 x 2 gang sockets in a ring, you could spur from each to provide 8 x 2 gang sockets in total - in practise I would try to put more outlets into the ring, and fewer on spur, unless all this spurring saves £££ in cable - but this is just an illustrative example). I take it as a given that you should not spur from a spur (although I don't yet see why this has to be limited by a hard rule, rather than Ohm's law application, but this is probably want of knowledge on my part). I guess it is also common sense to perform separate load calculations at any point on the circuitry where supply is only from one direction rather than the two directions allowed by the ring. Please, which is correct: one spur per outlet, or one spur per ring main?
Sincere thanks for sharing your knowledge on this thread and forum. Please, don't be fooled by any occasional bits of knowledge - it's only that I read a book last night. I am just starting out.
Just getting started with a view to DIY electrics on my house extension in a few months time, and ideally would like to map out the current circuits so I can plan the best way to join up, or where new circuits may be required etc.
2 Questions
I reckon I can do some DIY non-live testing of each ring main circuit, firstly establish which outlets are included on each ring main, then all that area of work (R1 + R2) / 4 etc etc to detect any faults on the ring or at the outlet; but can anyone point me in the direction of a method for working out what order the outlets sit on the ring? Or do you never really know until the floorboards are up? It occurs to me that you can do a long sequence of trial and error by disconnecting the outlets 2 at a time, then anything not working must sit between these two (or if everything else still works they must be adjacent), and slowly build a picture. Please, is there a method easier and quicker, perhaps with a multi-meter?
I read online that you can only have one spur per ring main, but I also read that if you only have two sets of wires at a socket, you can spur at this point without checking everywhere else - which infers one spur at any given point on a ring main (eg: 4 x 2 gang sockets in a ring, you could spur from each to provide 8 x 2 gang sockets in total - in practise I would try to put more outlets into the ring, and fewer on spur, unless all this spurring saves £££ in cable - but this is just an illustrative example). I take it as a given that you should not spur from a spur (although I don't yet see why this has to be limited by a hard rule, rather than Ohm's law application, but this is probably want of knowledge on my part). I guess it is also common sense to perform separate load calculations at any point on the circuitry where supply is only from one direction rather than the two directions allowed by the ring. Please, which is correct: one spur per outlet, or one spur per ring main?
Sincere thanks for sharing your knowledge on this thread and forum. Please, don't be fooled by any occasional bits of knowledge - it's only that I read a book last night. I am just starting out.
