Is a "ring"-type cirquit essential for the sockets in one-bed flat?

[Dave Plowman (News)]

Err, what other purpose do you thing a 'fuse' has?

[Dave Plowman (News)]

I'm not so sure - electric heating was around long before rings which were a post WW2 device - or at least only became common then. Several birds were killed with one stone - the standardisation of an outlet for any portable appliance, rather than the many before. More economical use of cable. And the ability to have near limitless outlets - since in practice domestically few would be loaded to maximum. That it predated the hundreds of low current appliances we all have now was simply brilliant foresight. Or luck.

[Lurch]

On Fri, 27 Apr 2007 09:55:17 +0100, "Dave Plowman (News)" mused:

Well, whether it was heating or not, the idea behind the ring being easily achievable by running an extra cable form the end of a radial was the main point in the post.

[Andy Wade]

an interesting read.

I quote:

The ring final circuit

---------------------- It was decided during this study that the alternative of providing a separate circuit fused at 15 amperes for each principal room which would feed all socket-outlets in that room: "is attractive as compared with pre-war practices but is less flexible in installation than the ring-circuit, provides less flexibility in loading and, except possibly in the smaller type of house, is not so economical." It was realised that a post-war Britain would continue to suffer from a massive shortage of raw materials and it was estimated that the proposed changes to the ring-circuit and single-pole fusing would show a saving of approximately 25% compared with pre-war regulations. The opportunity to improve both consumer safety and convenience due to the interruption in new building during the war and the massive programme of building which would be required after the war was recognised at an early stage. Initially, a majority favoured a new British Standard for a 10 A, fused, shuttered socket-outlet and a plug with round pins conforming to BS 546. The final unanimous decision was for a 3 kW (230V; 13 A) socket-outlet with fused plugs.

[Dave Plowman (News)]

Again I'm not so sure. I'd say very few had radials converted to rings - after all pre-war 15 amp radials frequently didn't have earths. My parent's house was built in the mid '30s and they specified one power point (15 amp) in each room, but these were two pin. Rings were normally installed on new builds or refurbishment - many such needed after WW2.

[Owain]

Who rarely comes knocking at the same time as means and motive.

Owain

[Clive Mitchell]

In message , Lurch writes

So what was wrong with plugging the heaters into the lamp sockets with those lovely Bakelite bayonet cap plugs?

[zikkimalambo]

How?

Do you plug/umplg each applience into the dual socket, or do you have some kind of "adapter" to allow you to plug them all in at once?

Is this a rented flat?

[Owain]

No, actually you'd join the end of one radial circuit to the end of another radial circuit and add some more sockets on the new bit.

The less conscientous would leave the fusing as 15A on each leg...

Owain

[Dave Plowman (News)]

[Andy Hall]

Exactly.

[Axel G]

Yes, I have to confess, there is actually currently only one double socket in the kitchen. From this, I have two extention leads: one feeds the washing machine and the dishwasher. The other is fixed just above the work top, and has four sockets feeding the kettle, toaster, mike, and kettle.

It will be soon.

Thank you to all for the helpful responses.

Axel G

[Dave Plowman (News)]

Do some sums by adding up the maximum load of each of these - the washing machine and dishwasher can easily exceed the 13 amps allowed on an extension if both used together and both heating water. Likewise the kettle and toaster. I'm surprised you don't have fuses constantly blowing.

Then it really needs sorting. You might be capable of knowing not to use the washing machine and dishwasher together but a tenant likely won't, and shouldn't be expected to.

And FWIW I'd consider any multi outlet extension in a kitchen a safety hazard and I'd bet your local fire service would too.

[Axel G]

Yes. I reckon I'll add two double sockets above the work top and from there run 2.5mm cable back to the CU and use a 32 amp fuse then. It will end up being a normal ring main except for the office spur, going off from a junction box.

One question: I'll need to run the cables up the back of the kitchen units - emerging from behind the top of the skirting board and going vertically up to the new double sockets, just above worktop level. Is it OK to use plastic trunking in this sort of situation? In fact, is trunking essential at all, if the cable is behind the units?

Thanks,

Axel

[Andrew Gabriel]

is an interesting read.

Elektor magazine did an interesting article on the history of the 13A plug/socket on its 50th birthday, 1996 IIRC. On the basis that I never through such things out, I will still have it somewhere, but finding it might not be easy.

[meow2222]

Although few 15A radial to 30A ring conversions occurred IRL, that was one of the considerations.

However the idea was not to run a 2nd wire back to the fusebox, but rather to join a cable from one 15A socket to another one on another fuse. So the original rings were on 2x 15A fuses, not 1x 30A. A semi- horrible situation, but a real improvement on 15A radials.

In practice of course hardly anyone did this, they left it as is until the eventual rewire decades later, meanwhile using all sorts of horrible bodgery. Slightly dodgy things remained on sale in the shops until early 70s. People made the really bad ones themselves. I still remember various short leads, including one that was a 2A plug to a

15A socket!

NT