Quote Originally Posted by Glot View Post
The ring circuit was introduced in to the UK during the war to save copper. Each outlet is fed via two cables of half the size. The cable is protected but an overload device matched to the two cables in parallel. It's not a good system. One issue is a break in one cable can allow an overload in the other. However, this isn't as bad as it sounds when you understand how cable current ratings are calculated ( as every electrician should!).
That story about saving copper during the war is not supported by any documentation at all https://en.wikipedia.org/wiki/Ring_c...istory_and_use. To declare it "not a good system" is to ignore the crucial part of the system that actually makes it a very good system the BS 1363 plug and socket system. We have waited nearly 60 years for Australian designed plugs and sockets to come close to providing the same number of safety features (shuttering and insulated pins). The reason why the ring main circuit wasn't adopted here is simply because the plug and socket chosen for commercial reasons https://en.wikipedia.org/wiki/AS/NZS_3112#History don't have the features (fusing) needed to make a ring main a viable choice.

The current wiring rules allow for radials in the UK yet still the most common installations are ring mains? Are UK electricians dumber than Australian ones? I doubt it they make their choices for valid reasons. The fact that it isn't a choice you could make means you probably haven't had any exposure to its advantages. For instance a broken earth in a radial system doesn't stop the system from working but makes it dangerous. In a ring main you get two earth paths.