Euro Electrics

[John Rumm]

Even my mums place with its early 1900's lighting circuit (replaced years ago) had seperate circuits... Common socket circuits seem more common in fact.

[Mike Halmarack]

That would make interesting reading. Have you read it yourself?

-- Regards, Mike Halmarack

Drop the EGG to email me.

[Owain]

The fact that standards would be applicable to all countries would have little impact on quality of workmanship. It's well understood that CE marking has lead to a lowest common denominator approach to standards throughout the EU.

What affects quality of workmanship is *local* training, qualification, and, dare I say it, regulation.

Owain

[Owain]

They also like little platforms in their loos to examine turds for worms. The Germans can do what they like but why force it on Britain.

The use of a ring circuit where the total demand is anticipated to be within the ring capacity, and to allow flexibility in locating loads and benefit from the increased capacity of two conductors in parallel matches commercial building installation, and distribution, practice in many EU countries.

We *used* to use submains and multiple small CUs in assorted cupboards all round the house. We don't any more.

Owain

[Mike Halmarack]

This is the way I see it too. Given the "Us and them" context of this thread, bald statements about the facts and figures are more likely to be based on the effects of flag waving, rather than switch toggling.

Yes, for some the element of uncertainty is a convenient reinforcer of the argument.

Since these counties contain a high proportion of the worlds population, comparisons between "the UK and the rest of the world" isn't significant. Even a highly organised society can be forgiven for not producing data on events that don't occur.

That seems relatively convincing. It won't please everyone though.

-- Regards, Mike Halmarack

Drop the EGG to email me.

[Peter Parry]

Electrical fires in the UK attributable to fixed wiring are much less than 10% of the total attributable to electrical faults. The vast majority are due to portable appliances.

In the UK the number of household electrical fires caused by electrical faults is about 10% of the total. In France and Germany it is about 25% of the total.

It was the dire German Shuko plug being touted as the "harmonised" solution. The house I had for a time in Germany had all three phases brought in, the "earth" was a 6in long rod pushed into dry sand by hand. In the living room one socket was on one phase and the other socket on the other (there were only two), 400V between sockets.

The overhead feed went to three fuses in the attic where poor connections often led to them smouldering gently (24kW instantaneous water heater). It's the only house I've ever had where turning a tap on caused the lights to dim and the TV picture to shrink.

Complete nonsense.

"Answer given by Mr Liikanen on behalf of the Commission (11 November 2003)

"The Commission is aware of this non-harmonised situation in Europe with regard to the plug and socket outlet system. All attempts to harmonise plugs and socket outlet systems for domestic use (i.e. up to16A rated current) throughout the Union, which were heavily inspired by the Commission, have been abandoned in the past. The majority of the Member States do not see the need to agree on a harmonised solution. Various attempts were made by the European Committee for Electrotechnical Standardisation (Cenelec) to agree a standard on these plugs, however, after several years of intensive meetings it has not been possible to find consensus with the manufacturers of plugs and socket outlets"

Eh? Which "modern house" is this?

[Peter Parry]

Of course. The UK has the best collection of fire data in Europe, it can be found via:-

World fire data can be found at

however varying reporting standards and definitions have to be considered when comparisons are made.

As a recent report from the European Copper Institute and European Association of Electrical Contractors said "Many conclusions are based on UK statistics, since the UK is the country for which the most detailed information is available. The UK has a high installation standard, and hence extrapolating UK results to other markets tends to underestimate the real safety hazard, and err on the conservative side."

The figure for 25% of household fires in France being of electrical origin (compared with 10% in the UK) came from Centre National de Prévention et de Protection.

In France, the ANAH (Agence Nationale pour l'Amélioration de l'Habitat) estimated that about 200 000 individuals suffer burns in their homes each year (population 61.7 million) and that one in four of these victims are children under 5 years old (Limiter les risques de brulures et d'electrocutions, ANAH, 2001, 8 pages). The report claims that electric shock is a major cause of these accidents and comments that the figures indicate that the number receiving electric shocks is far greater than should be possible with a properly designed and maintained installation.

[Mike Halmarack]

Need I have asked? :)

In other words the information lends itself to being moulded to suite the user's purpose, as it would need to be, when attempting to support the statement on which this aspect of the thread was based. That is: "The fact remains that the UK electrical system is statistically extremely safe in comparison to the rest of the world".

-- Regards, Mike Halmarack

Drop the EGG to email me.

[dennis]

One like mine where all the downstairs is on one ring.

That's kettle, microwave, washing machine, dryer, portable airconditioner, toaster, vac......

So much for diversity.

The ring main was designed years ago when there would have been an electric fire carried about the house not one where there are many electrical appliances.

Even then it was a compromise of safety v cost and a poor one at that IMO.

The safest thing to do with rings is to fit a 22A MCB... 30A fuses are too big.

[Andrew Gabriel]

I was following it in the 1990's when I was working with ETSI. I think there were about 5 attempts at this standardisation (some may date back earlier).

At that time, the EU had laid down that any common plug/socket would have to be different from any currently existing so as not to give some countries an economic advantage over others. In most cases, there were sound reasons technical for not using most of the existing connectors anyway. E.g. Shuko was ruled out because it mates with too many other outlets for which it was not designed, including several sockets in common use in the EU with no earth connection.

At one point, there was nearly agreement on a 2-pin plug for those countries which wanted it, but even that fell apart.

[Mike]

And the answer is whatever is used now is probably not optimal, if not downright dangerous (e.g. parts of France). Hence the proposal for a common new design (NOT the German design as somebody suggested). Adoption of this would have allowed a new common set of wiring regulations behind it as well.

There's a real problem. Many countrie's electrics are poor to abysmal and governments want to begin mass upgrading but without a common standard it is difficult to justify pressing the go button. Indeed if they did at the moment it would be for the German system which still has a lot of problems.

Apparently there is going to be another attempt in 2006/7. Hopefully there will be a little less vested interest from certain parties this time as this won't be a veto-able item this time.

[Mike]

Of course it understands it. The IEE were there explaining it. Problem is although it is better than a lot, possibly most of Europe, one cannot have harmonisation on one countries existing standard. And few apart from the UK regard ring mains as safe.

Works for most things. For example the Internet we are using now wouldn't work if each country had their own standards.

[John Rumm]

Are you likely to use all of those at one time and for prolonged periods?

How long does your kettle take to boil, or your toaster toast? Both are short term loads and can be largely ignored. Same is true for the microwave in most cases.

The washing machine and dryer are potentially large users and it is for this reason that kitchens are often placed on their own ring circuit.

So in answer to your statement "So much for diversity", you have just described it in action.

True. But the modern usage pattern may change the number of sockets you provide, and possibly the number of circuits. It does not however make switching to radials any more attractive (other than for fixed high point loads which ought not be on a ring circuit anyway).

The safety of a UK speced ring final circuit is first rate if installed to guidelines.

You have each connection point connected to a pair of cables that in many cases will be able to supply in 40 to 50A continuously without any negative effects (i.e. well in excess of the fuse/mcb size). Fitting a

22A MCB in many cases simply acquires you many of the limitations of a small radial in exchange for no apparent benefit.

[Mike]

The average householder probably has no idea what a ring is, let alone which rooms share rings. They could, and do, thus plug in more appliances than the ring can take.

There's a report showing they do. Although very large older houses may have two lighting rings, smaller (even 4/5 bed) houses of that period as well as flats tend to lose all lighting when the trip goes.

And yes I'm British.

[bigcat]

so quite obviously they dont understand it. The comments quoted also demonstrate that.

The fact that the IEE is there to explain it doesnt imply they'll understand. Calling our ring system unsafe is entirely incompatible with understanding it, or even having basic statistical facts.

Further comment seems pointless.

NT

[Stefek Zaba]

That's actually pretty hard to achieve. Somewhere in the maze of twisty little links that is the IEE website is, or was, a nice little study of how even a heavily-applianced kitchen stays within sensible

2.5mmsq-rating territory, with a pretty bargraph showing how the appliances which are heavy short-term loads are damn unlikely to cause a *sustained* overload: kettles boil within a few minutes, dishwashers and washing machines don't heat their water for more than 10 minutes at a stretch, usually less; tumble-driers do go on, but tend to be closer to 1kW than 2kW; ovens have thermostats; microwaves aren't used for long periods.

You'd have to have all those on the go, *and* a notably unbalanced ring (one leg a lot shorter than t'other to where these concentrated loads are) to 'plug in more appliances than the ring can take'. To get the sustained overload to happen, your choice of loads has to be just enough to overheat the cable, but below the MCB trip point.

However, arguments with average-case, diversity-taken-into-account seem to be above the heads of the wannabe SafeTee PoeLiss - even though the LV distribution network is designed with load-averaging very much in mind...

Stefek

[Owain]

On the contrary. The ring circuit (not ring main) was designed to replace the previous inconvenient arrangement of a 15A 'power plug' in each room together with 5A 'plugs' for table lamps, radio, etc (usually

3 to a circuit). It was specifically the foreseen increase in the number and diversity of portable appliances that lead to the adoption of the ring circuit which allows an *unlimited* number of sockets supplying predominantly low power appliances. This it does extremely well.

Electric heaters were usually wired on 15A radials anyway, and that practice was expected to continue. Also, postwar housing was usually intended to have some form of fixed heating installation anyway, so the ring circuit would not have been used for the main heating load.

The point where the ring circuit falls down is the increase in high-power kitchen appliances, which really only happened in the last

20-30 years. If you take the washing machine, dishwasher, tumble dryer and combi-microwave off the ring, one ring will usually be adequate for a whole house, although convenience and good practice encourage the provision of two in all but the smallest houses.

Owain

[Owain]

I thought the 16A BS4343 CEEFORM was going to be the new Europlug at one time. I certainly don't think having big blue sockets would be an aesthetic improvement in most decors.

Owain

[dennis]

No I have just listed some appliances which would bust diversity on my ring main if I used three or four of them. Diversity doesn't work very well.

I didn't even bother with the bread maker, foreman grill, rice cooker.....

Radial circuits are safer and cost no more (1 MCB at the most).

Ring mains can appear to be working fine but may have a break that makes them function as two radials (2.5mm T&E) with a common 30A fuse. It is difficult to find such a fault and they may exist for years just waiting to start a fire.

2.5mm T&E is speced at 22A IIRC. The general rule is that you should never use a fuse that exceeds the cable rating. Ring mains break this basic rule.

[Peter Parry]

You can do that with almost any bit of information.

The data supports that statement quite well. Things like the number of people killed in fires is relatively accurately recorded throughout Europe. If you use that to prove your case it is likely that the data is quite accurate and complete.

Where you need to take care is in things like "number of fires". Some countries only record those where a fire appliance was deployed and extinguished the fire. Some report all those where an alarm was raised (even though the fire was out by the time the fire appliance arrived). Some only report those where damaged exceeds an arbitrary threshold. There is also unreliable reporting in some places so data is likely to be incomplete. "Injury" is also notoriously inconsistently recorded with some countries only counting injuries which lead to hospital treatment and others reporting the slightest scratch.