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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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    One ring final circuit is one ring final circuit normally protected by a 32 Amp miniature circuit breaker. That limits the total loading to a maximum of about 7kW. What will you use at any  one time? Will the total circuit loading exceed 7kW? Perhaps more than one circuit is a wiser option, rather than just one ring final circuit. That way you are reducing the risk of overloading and the inconvenience caused by that if the M.C.B. trips off. A radial or two can be very useful, easy to install and self contained.


    Appendix 15 of B.S. 7671 suggests that appliances such as cookers, ovens and hobs of 2kW or above should be run on their own circuit, not from a ring final. 


    Fig. 15B in B.S. 7671 shows some radial options and requirements.


    Z.
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  • 0
    One ring final circuit is one ring final circuit normally protected by a 32 Amp miniature circuit breaker. That limits the total loading to a maximum of about 7kW. What will you use at any  one time? Will the total circuit loading exceed 7kW? Perhaps more than one circuit is a wiser option, rather than just one ring final circuit. That way you are reducing the risk of overloading and the inconvenience caused by that if the M.C.B. trips off. A radial or two can be very useful, easy to install and self contained.


    Appendix 15 of B.S. 7671 suggests that appliances such as cookers, ovens and hobs of 2kW or above should be run on their own circuit, not from a ring final. 


    Fig. 15B in B.S. 7671 shows some radial options and requirements.


    Z.
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