American electrics

[:::Jerry::::]

,

appliances? Less

considered quite

bedrooms; in

sockets whilst

Possibly, and how many of those sockets you need will ever be used for anything over 2Kw?

[Doctor Drivel]

On cue the idiot responded.

[Martin Angove]

As you are "GMT not EDT" then:

Probably the most common radials to be found in Britain are those for showers (no sockets, obviously), lights and cookers, however we're talking specifically about circuits supplying socket-outlets.

There are three "standard" circuits for use with BS1363 socket outlets:

"A1" is a ring topology with 30 or 32A protection wired in 2.5mm2/1.5mm2 cable. Such a ring can serve a floor area of up to 100m2.

"A2" is radial with 30 or 32A protection wired in 4mm2/2.5mm2 cable (though it is only really rated for "clipped direct" and many people advocate the use of 6mm2 cable instead). This type of radial can serve up to 75m2.

"A3" is radial with 20A protection (though possibly more often found with 15/16A) wired in 2.5/1.5 cable and serving up to 50m2.

The IEE On Site Guide says "A ring or radial circuit, with spurs if any, feeds permanently connected equipment and an unlimited number of socket-outlets and fused connection units." (Appx 8)

Given that an average Valleys terraced house will have a floor area of

70 to 80m2 you can see that it is perfectly possible to wire the entire house with one ring circuit, and it may even be possible to wire it with one 30A radial. It will certainly be possible to wire it with two radials of either rating (cable length aside). You can see that there will be many more than your "one or two outlets per circuit" and that the circuit will of necessity cross both room and floor boundaries.

Indeed, for a house shaped like a terrace (i.e. long and narrow), a radial may be the most economical use of cable.

Therefore, from a discrimination point of view, there is absolutely no advantage at all from running radials.

If we follow your idea of radials feeding just a few outlets - let's be charitable and say one radial per "room" - then you begin to escalate the cost of the system enormously. My house is unusual in that I have three ring (East, West, Kitchen) and two radial circuits (utility/outside, fridge). Five sockets circuits is a lot for a house with a floor area of some 80m2 (three bed semi). With the "one radial per room" idea though, I'd need even more!

Three bedrooms One for hall/landing ("office" area on landing) living room kitchen dining room utility outside fridge

Makes a total of ten circuits; double the number. I have a 12-way board which, at the moment, has a few spare ways. With the new regime that board would be over-full:

10 sockets radials 2 lights 1 cooker 1 heating radial

makes 14. Also the utility/outside circuit I have installed is run from an RCBO rather than from the RCD which commonly feeds the rings. This RCBO takes two slots in the board so now I need 15 ways; whatever, it means a bigger board. A 12-way board kit is available from Screwfix for as little as £60. Bigger boards are a lot more expensive as they are less common.

And then what about the spare ways I currently have? One of them is earmarked for a supply to the shed I'm planning. One of them might be used for a third lighting circuit. Perhaps the best way would be with two 10 or 11 way boards, one exclusively for the sockets radials and one for everything else? Never mind the cost, what's the wife going to say?

Even after all that, you *still* have multiple outlets per circuit, and hence unfused connections (which I think were the original argument) are still a big problem. In total we have the equivalent of 31 double sockets in the house. This is an average of three and a bit per circuit to the "one radial per room" plan, though two of the radials only actually serve one double each.

I wasn't going to add any more to this thread, but I'm intrigued how you can be such a radial fan when it doesn't (in real life) solve any problems.

Hwyl!

M.

[Doctor Drivel]

I put 4 sockets with TV point, in each corner of the living room. People were confused and thought it overkill. The TV, VCR, Stereo bits, etc took the four up. I could arrange the furniture to just about anywhere, everyone else had double adaptors and the TV always in the same place.

[Doctor Drivel]

Not really. Rings came about because of ships, to reduce the amount of cable, and one lighting cable could be strung around the whole ship. Many British go to Spain and take with them UK cables and CUs and fit Spanish plugs, using rings. The Spanish authorities cut the circuit off when they see them. The Spanish forbid rings. Cheeky bastards I know, when you see the state of Spanish wiring. The new Euro wiring standards is to only have radials. Not finalised or approved yet, and still up in the air, but looking that way.

There is no evidence to prove that rings are safer than radials.

[John Cartmell]

One will have a heater attached whilst many of the others will be running computers that require no more power than 2 or 3 AA batteries could provide.

But I was illustrating that times change.

[Doctor Drivel]

Tell that to the Europeans.

[Doctor Drivel]

When was it universally adopted? I think the 1960s. Rings are "not" mandatory. Many are going to radials as rings create magnetic fields around a house. Many people are susceptible to this. Radials avoid the problem

[Doctor Drivel]

Most of the world have unfused plugs and radials. When installed properly they appear safe enough. Many appliances have in-built fusing in these countries too.

Some Continentals think we are mad. A washing machine. A fused plug behind, which is a pain to get at. A fused spur above, over the worktop, with a fuse in, and the ring mcb, and then an RCD. They say we overkill. If there is a fault and the fuse blows behind the washing machine? They thing it is silly to have a fuse in that plug, when a fused spur gives protection above. I agree with them. I know some people who remove the fuse and put a copper wire across the washing machine plug, so they don't have to drag the washing machine out. A good thing? Maybe not as the appliance may be faulty.

[:::Jerry::::]

Other than placing the responsibility for appliance 'final protection' in the hands of the user (who might have little grasp of the whys and wherefores) rather than those who do.

[Andrew Gabriel]

1946 supplement to the 11th Edition Wiring Regs was when it was officially sanctioned, but people had started using ring circuits beforehand. Installation was universal by 1950, except in towns which didn't yet have a 200-250V AC mains supply (13A sockets were not allowed on DC supplies or AC supplies with no neutral).

[:::Jerry::::]

overkill.

remove the

That is one of the many failing with ring circuits I've tried to illustrate, but the IEEE 'dinosaurs' just can't see the wood for the trees....

[:::Jerry::::]

,

I read DD as meaning that the BS1363 plug was not universally adopted until the 1960s.

As for radials, they are still being installed, they just have either a FCU or BS1363 socket at the end, as of the date of sanction / implication, the date is most telling - being a time of shortage, final ring circuits using less raw material than radials circuits....

[Gerd Busker]

The fundamental difference between "continental" installations and UK installations is that here in the UK the plug is fused. This allows for higher capacity circuits (such as 30A rings) as you have some degree of over current protection in the plug.

In Spain, or the Netherlands, there is no fuse in the plug, so you will need to reduce the circuit rating to keep things safe. In NL most circuits are fused at 16A.

So if you drop a knife on a CD player power cable it trips the fuse for that radial. And before anyone starts crying about the whole house being out of power because of a CD player short: We use many radials with only a few sockets on each.

There is little point using a ring circuit for a 16A circuit (yes, yes I know all the arguments for and against). Why they would be forbidden is a different question, but I have not yet come across a situation where I would need one, as you usally have multiple radials instead of the one or two rings common in the UK.

For exceptions (ovens, etc) you just lay 3-phase or 2 circuits. It's rare to find an appliance that requires a single phase >16A that doesn't have the option of a double plug in the NL.

Gerd.

[Owain]

That is not a failure of ring circuits. That is a failure of people who install sockets behind the appliance, instead of to the side.

If you want to you can wire the washing machine into an unfused flex outlet unit below the worktop and use an FCU above, or use an unfused

15A socket below the worktop.

But there are good arguments for not using general-purpose rings and assuming load diversity when it comes to kitchen appliances anyway.

Owain

[Doctor Drivel]

My mothers house was new in 1953, was 250V, 3 pin plugs and radials. Radials are not outlawed and rings are not mandatory. Even today it is take your choice. AFAICS, rings became common in the 1960s.

[Pete C]

There's not /that/ much difference between a 30A ring and 2 16A radials. MCB's are cheap these days, also rings are harder to fault find and the ring can get a break in it.

Anyway a 13A plug fuse can take 26A for up to 30 mins before breaking, I'm sure a 16A MCB can do better than that.

cheers, Pete.

[Andrew Gabriel]

There will undoubtedly be some variation across the country; the building trade has always been quite regional. My parents bought their house new in 1955, and by then the builders were no longer offering round pin sockets -- a few years before you could still ask for round pin sockets if you really wanted them.

You can still install BS546 15A sockets on radials today if you really want to, and have the installation conform to the current wiring regs.

Radials were certainly gone by then, and 10 years earlier in many places. Also note that both rings and fused plugs existed before the 1946 supplement, but there was no standard. Fused plugs from different manufacturers were not interchangable, and I doubt the ring circuits were all standardised at 30A. Some of the designs had the fuses as the plug prongs, and some fused both prongs (as not all areas had a 'neutral'). There are tales of the fuses coming off and getting stuck in the socket.

[bigcat]

Even after making yourself look unclued in this thread, you still insist the others know even less than you. Welcome to uk.diy.ld.

NT

[Harvey Van Sickle]

On 24 Jul 2005, Andrew Gabriel wrote

-snip-

1970 or thereabouts? Are you sure?

I'm positive that when I moved to the UK in 1982, it was still the practice to sell small appliances without a plug -- that was sold (and charged for) separately.

(It got my goat: buy an expensive appliance, and then then be charged an extra quid or so for a plug....cheap bastards....)