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I`ve been thinking

OK the title might startle some who know me.

Ring Final rules.

What is the intention behind the rule "no more spurs than points on the ring".

I think most of us who have run rings would almost exclusively put every point on a ring and no spurs at all.

Spurs are then usually just additions.

One spur max per point.

One spur allowed at origin.

If I saw a ring with say 12 points on ring and one ring per point and say 1 point at origin that would be 12 on ring and 13 spurs that would not worry me.

In fact if I saw say 5 points at origin it would not worry me either.

If I saw 12 on ring each with one spur then 5 spurs at origin then 11 spurs on joints between points woul I worry?

No I would not although this "golden rule" would have been well and truly broken.

I think the rule intention was purely good housekeeping to keep us all on the straight and narrow.

In fact some on here have mentionded a ring in a loft with junction boxes dropped dow to spurs. Therefore all spurs and not on ring.

Note I did not pick the number of 12 points on ring for any reason, I could have picked 5 or 50 or 5000.
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  • No, I think the intention is always that the spurs are wired in the same stuff as the ring, namely 2.5mm. IF you had 4mm radials the 2 socket limit would make no sense.


    In any case the rating of 2.5mmsq is 27A for surface wired or in plaster - which would have been the options when it was being dreamt up. Dont forget that part L and all this thermal stuff ony go t going after the 1984 revisions to the building regs - because until you have central heating the indoor and outdoor temps in all rooms without a fireplace are not so different.
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  • No, I think the intention is always that the spurs are wired in the same stuff as the ring, namely 2.5mm. IF you had 4mm radials the 2 socket limit would make no sense.


    In any case the rating of 2.5mmsq is 27A for surface wired or in plaster - which would have been the options when it was being dreamt up. Dont forget that part L and all this thermal stuff ony go t going after the 1984 revisions to the building regs - because until you have central heating the indoor and outdoor temps in all rooms without a fireplace are not so different.
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