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Which is best, long ring final with 2 spurs or short ring final with more spurs?

Former Community Member
Former Community Member
Good afternoon, hope you are all well. I have been re-evaluating the number and position of sockets in my bungalow, and considering having a few more added for convenience. Currently I seem to have a relatively short ring with 2 long spurs. If I measure the new route for cables incorporating the existing spurs and new sockets, I anticipate a total cable run of about 100m. From what I gather on this forum this is the limit for a ring final per 100m square of floor. Question is, is this a good idea, or should the ring final be made to run a shorter route and add more spurs, not exceeding the number of sockets on the ring, in order to keep volt drop to within acceptable limits. Not being an electrician I have used online cable size calculators to see if my idea is anywhere close to being ok and they come back with a huge 25mm squared cable. I am clearly out of my depth here hence the question. As always, many thanks in advance. Kind regards, Simon   
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    Which is best, long ring final with 2 spurs or short ring final with more spurs?



    In may ways it's swings and roundabouts. In terms of voltage drop you're trading a reduced load (on a spur) against having two cables rather than one (ring) - so it's down to the particular individual circumstances (which will probably vary over time anyway). In terms of other design factors, such as Zs, then a ring probably wins, usually.


    In terms of flexibility and future-proofing (e.g. adding an extra socket or two in the future) - an extended ring almost certainly wins over a spur - since you can add as many sockets as you like to a ring, but you can't (other than changing a single to a double) on a spur.


    If you prefer spurs then you might be better not having a ring at all and just have a simple radial circuit (with as many branches as you want).


      - Andy.

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  • 0

    Which is best, long ring final with 2 spurs or short ring final with more spurs?



    In may ways it's swings and roundabouts. In terms of voltage drop you're trading a reduced load (on a spur) against having two cables rather than one (ring) - so it's down to the particular individual circumstances (which will probably vary over time anyway). In terms of other design factors, such as Zs, then a ring probably wins, usually.


    In terms of flexibility and future-proofing (e.g. adding an extra socket or two in the future) - an extended ring almost certainly wins over a spur - since you can add as many sockets as you like to a ring, but you can't (other than changing a single to a double) on a spur.


    If you prefer spurs then you might be better not having a ring at all and just have a simple radial circuit (with as many branches as you want).


      - Andy.

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