Editing Ring circuit (section)

{{Short description|Electrical wiring technique}}
{{About|a mains power configuration|circuits where the components are connected in a ring|ring modulation|and|phase-locked loop}}
{{Redirect|Ring main|the London water infrastructure|Thames Water Ring Main}}
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{{Electrical Wiring Sidebar}}
In [[electricity supply]] design, a '''ring circuit''' is an [[electrical wiring]] technique in which sockets and the distribution point are connected in a ring.  It is contrasted with the usual [[radial circuit]], in which sockets and the distribution point are connected in a line with the distribution point at one end.

Ring circuits are also known as ''ring final circuits'' and often incorrectly as ''ring mains'', a term used historically,<ref>{{cite web |title=How To Use Your Wylex Plugs & Sockets |url=https://xo4.uk/wylex.pdf |publisher=Wylex |accessdate=3 December 2019 |archive-date=3 December 2019 |archive-url=https://web.archive.org/web/20191203005102/https://xo4.uk/wylex.pdf |url-status=dead }}</ref> or informally simply as ''rings''.

It is used primarily in the [[United Kingdom]], where it was developed, and to a lesser extent in [[Ireland]] and [[Hong Kong]].

This design enables the use of smaller-diameter wire than would be used in a radial circuit of equivalent total current capacity. The reduced diameter conductors in the flexible cords connecting an appliance to the plug intended for use with sockets on a ring circuit are individually protected by a fuse in the plug. Its advantages over radial circuits are therefore reduced quantity of copper used, and greater flexibility of appliances and equipment that can be connected.

Ideally, the ring circuit acts like two radial circuits proceeding in opposite directions around the ring, the dividing point between them dependent on the distribution of load in the ring.  If the load is evenly split across the two directions, the current in each direction is half of the total, allowing the use of wire with half the total current-carrying capacity.  In practice, the load does not always split evenly, so thicker wire is used.