Just curiosity really, but on various occasions we have discussions here
that touch on the relative merits of the UK vs Euro style electrical
installations and fittings.

I had always thought that the UK regs and practices were amongst the
best, but perhaps not everyone agrees.

Anyone with experience of non UK electrical installations care to
comment on which systems they feel are better/worse and why?


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
...
Just curiosity really, but on various occasions we have discussions here
that touch on the relative merits of the UK vs Euro style electrical
installations and fittings.

I had always thought that the UK regs and practices were amongst the
best, but perhaps not everyone agrees.

I don't agree for one. More importantly neither does almost every
electrical representative to the EU apart from the UK and Malta.


Anyone with experience of non UK electrical installations care to
comment on which systems they feel are better/worse and why?

The view of a friend working for the EU directorate on this matter in the
mid-90s was roughly as follows :

The UK plug/socket is dangerous and probably causes more electrical fires
than any other piece of electrical equipment. In the 90s the rest of Europe
worked on a harmonised version of the IEC plug/socket only for the UK to
scupper it. Note that the UK plug was actually designed in Sweden and
rejected as lethal, though we have since then added the shields to the L and
N pins.

Similarly although the IEE have done well getting ring mains systems safe,
it is felt they rely on diversity too much for a modern house where there
may be large numbers of high current consumption devices often in separate
rooms where the users do not realise they are using a common ring. Also the
allowed practice of adding almost uncontrolled numbers of extra sockets to a
ring makes this worse. It is accepted that UK house make far less use of
electrical heaters than some other countries due to our cheap supply of gas
but pointed out that this won't last indefinitely.

The proposed EU recommended wiring system consists of separate feeds to each
room with a small CU in that room with a breaker for lights and one for each
group of sockets/piece of equipment. The best CUs actually fit under the
light switch by the door which hinges up. A simple look round the room will
soon tell you if you are taking too much current (and the much more likely
to be correctly rated trip in that room blows anyway - not taking out the
whole house as in the UK). This is not to say that any particular country
in the EU follows this approach to the letter today.

There was the intention in the EU to try for harmonisation again on this in
2007 but of course there may be more important matters to worry about now.


Others will strongly disagree with this of course so I'll put my flak hat on
now :-)

Mike wrote:
"John Rumm" wrote in message
...

Anyone with experience of non UK electrical installations care to
comment on which systems they feel are better/worse and why?

I did a thread recently on South African wiring, where one 15A round
pin socket per house was standard, and supplied the entire house.
Total fuses in house: 1
RCDs: 0
Earths: 0
plugs and sockets on appliances: 0



The view of a friend working for the EU directorate on this matter in the
mid-90s was roughly as follows :

Others will strongly disagree with this of course so I'll put my flak hat on
now :-)

Evidently he didnt understand our system too much.


NT

wrote in message
ups.com...
Mike wrote:
"John Rumm" wrote in message
...

Anyone with experience of non UK electrical installations care to
comment on which systems they feel are better/worse and why?

I did a thread recently on South African wiring, where one 15A round
pin socket per house was standard, and supplied the entire house.
Total fuses in house: 1
RCDs: 0
Earths: 0
plugs and sockets on appliances: 0


At least the house had a fuse and at least one socket. :-) I've seen them
full of extension cables to each room, and all connected to a set of screw
terminal connectors. One shack in Conchasa had bell wire to all the pinched
sockets the man of the house obtained from a British run building site. He
saw the guys running the two core bell wire to some sockets on the site, and
he thought that's how they were connected. He didn't know the bell wire to
the sockets was for transformers to door alarm systems. The shack had a
fridge/freezer, a television and a microwave cooker that he'd also obtained
on his travels. :-)

A nice little fire starter right in the middle of a shanty town, wouldn't
you think? LOL




The view of a friend working for the EU directorate on this matter in
the
mid-90s was roughly as follows :

Others will strongly disagree with this of course so I'll put my flak
hat on
now :-)

Evidently he didnt understand our system too much.


NT


The wiring schemes used throughout Europe are pretty well standard now. We
all use PVC insulated cabling for the installations. We all use the same
sorts of safety protective systems. But it's all down to the use of the
socket designs really. The British three pin version has become safer with
the use of insulated pins, as Mike says, but the same also applied to the
two pin plug tops used in other countries. These too have had half
insulated pins fitted as standard, because they too had people touching the
live pin as the plug was connected / disconnected from the socket, and a
stray finger went round the face of the plug top.

All in all, the basic installation schemes are very similar now though. I
find that the biggest differences are found when you travel further a field.

BigWallop wrote:

At least the house had a fuse and at least one socket. :-) I've seen them
full of extension cables to each room, and all connected to a set of screw
terminal connectors. One shack in Conchasa had bell wire to all the pinched
sockets the man of the house obtained from a British run building site. He
saw the guys running the two core bell wire to some sockets on the site, and
he thought that's how they were connected. He didn't know the bell wire to
the sockets was for transformers to door alarm systems. The shack had a
fridge/freezer, a television

well those 2 would run on 1A bell wire, long as no condensation on the
thermostat connections occurred.


and a microwave cooker that he'd also obtained
on his travels. :-)

On bell wire! gawd. 1.5kW... maybe 1.1kW. Would have to rely on low
duty cycle to avoid fire. 2 or 3 minutes it should just survive. I once
wired a stage lighting bank on bell wire, at the age of barely doule
figures, and it ran for several minutes before fuzenpoppen
wireallmelten funnysmellenburntwhysthat. Somehow it hadnt occurred to
me that putting a couiple of kW thru bellwire was a bad idea. I havent
forgotten


A nice little fire starter right in the middle of a shanty town, wouldn't
you think? LOL

Well, if he used 2 lengths of bell paralleled, one pair for L and one
for N it would have worked ok, for scary values of ok.

What Im wondering is what happens with the EHT to mains capacitances in
the transformer. The case would have EHT via small capacitances to
mains on it. Guess the current must have been low enough.

Reminds me of the caribbean setup where the gnerator feed cables were
various cut lengths twisted together and taped over, and the lot
dropped in a flooded ditch. Must have wasted fuel.


All in all, the basic installation schemes are very similar now though.

The ring circuit, plug fusing polarisation and earth is a fudamentally
different approach to safety to those used in most of Europe. Thats one
of the reasons Britain remains at odds with most of europe on
electrical wiring methods and standards.

Europe uses primarily non polarised sockets with unearthed appliances,
and unfused plugs relying of distribution board fusing, double
insulation and many circuits to avoid nuisance overload trips. This is
why they tend to assume our 30A rings are dangerously fused, and that
putting 50 sockets on one feed is potentially lethal.


NT

wrote in message
ups.com...
BigWallop wrote:
All in all, the basic installation schemes are very similar now though.

The ring circuit, plug fusing polarisation and earth is a fudamentally
different approach to safety to those used in most of Europe. Thats one
of the reasons Britain remains at odds with most of europe on
electrical wiring methods and standards.

Yes


Europe uses primarily non polarised sockets with unearthed appliances,

No - the proposed new standard socket had an earth pin so it was polarised
if you used the correct plug.


and unfused plugs relying of distribution board fusing, double
insulation and many circuits to avoid nuisance overload trips. This is
why they tend to assume our 30A rings are dangerously fused, and that
putting 50 sockets on one feed is potentially lethal.

Proposal was to move the trips to the room - a mini-CU in each room as I
mentioned, thereby cutting down on the km of cable needed.

In article ,
"BigWallop" wrote:

(Snip)

The wiring schemes used throughout Europe are pretty well standard now. We
all use PVC insulated cabling for the installations. We all use the same
sorts of safety protective systems. But it's all down to the use of the
socket designs really. The British three pin version has become safer with
the use of insulated pins, as Mike says, but the same also applied to the
two pin plug tops used in other countries. These too have had half
insulated pins fitted as standard, because they too had people touching the
live pin as the plug was connected / disconnected from the socket, and a
stray finger went round the face of the plug top.

All in all, the basic installation schemes are very similar now though. I
find that the biggest differences are found when you travel further a field.

In the area of France where I go, the sockets are set in a 15mm (?)
depression. This is designed to stop fingers being in contact with the
pins when the plug is inserted. I have not seen insulated types.

Also, the sockets have an earth pin sticking out. This polarises the
pins. Even so, the electrician who wired up our place, connected L & N
depending upon the direction of the wind blowing at the time ;-) I
have had to go round some of them altering the connections so as to make
it right for the Fr/UK adaptors.

I understand that in different areas of France there are different
'standard' plugs and sockets (at least two?).

__
Marcus

--
Marcus
email: marcus {att} frenchay {dott} demon {pointt} co {periodd} uk

In article ,
Marcus Foreman writes:
In the area of France where I go, the sockets are set in a 15mm (?)
depression. This is designed to stop fingers being in contact with the
pins when the plug is inserted. I have not seen insulated types.

The 2-pin 6A (IIRC) connectors have part-insulated pins.

Also, the sockets have an earth pin sticking out. This polarises the
pins. Even so, the electrician who wired up our place, connected L & N
depending upon the direction of the wind blowing at the time ;-) I
have had to go round some of them altering the connections so as to make
it right for the Fr/UK adaptors.

There is no defined polarisation for the French/Belgium socket,
even though the plug is not reversible. If you have any double
socket outlets or two-way adaptors, you will very likely find
they are hardwired the opposite way round.

I understand that in different areas of France there are different
'standard' plugs and sockets (at least two?).

Some parts of France weren't always in France, but most of France
is the connector you are describing.

--
Andrew Gabriel

not taking out the
whole house as in the UK).

Explain how please ? Thats a very sweeping statement.

Dave

"dave stanton" wrote in message
news

not taking out the whole house as in the UK).

Explain how please ? Thats a very sweeping statement.

I was thinking of older houses with about 6 fuses and possibly 1 RCD. All
lighting is on one trip, all sockets on another and so on. I agree more
modern housing is a bit better but that's a small percentage.

With the system proposed in the 90s, all rooms would have their own RCD so
you never take out anything outside the room.

I was thinking of older houses with about 6 fuses and possibly 1 RCD. All
lighting is on one trip, all sockets on another and so on. I agree more
modern housing is a bit better but that's a small percentage.

Which of course, and has been pointed out, is now verboten and has been
for quite a few years. Lighting circuits have been dual for years. Power
circuits not quite so long, in fact my house has one power ring circuit
circa 1970's but 2 x light circuits.
I don't really agree with your statements about UK circuits being
dangerous, especially when you look at the standard of practical wiring in
some countries. I don't mean design, I mean implementation by '
electricians' in those countries.

Dave

"dave stanton" wrote in message
news
I don't really agree with your statements about UK circuits being
dangerous,

Comments were from the EU harmonisation committee. I just happen to know
one of the EU reps on the committee.


especially when you look at the standard of practical wiring in
some countries. I don't mean design, I mean implementation by '
electricians' in those countries.

Quality of work is a problem in all fields. But a single set of clear
standards applicable in all countries would be a good start to getting
improvements.

In article ,
dave stanton wrote:
Which of course, and has been pointed out, is now verboten and has been
for quite a few years. Lighting circuits have been dual for years. Power
circuits not quite so long, in fact my house has one power ring circuit
circa 1970's but 2 x light circuits.

New house builders will skimp on almost anything - especially at the
budget end.

When I bought my present place in the early '70s, I provided one ring per
floor and one for the kitchen. And a lighting circuit for each floor. And
got a CU with spare ways. Despite being very tight for cash as a first
time buyer. But I only actually installed a minimum of sockets and lights
at that time - leaving the installation of what I really wanted as and
when I planned out and redecorated each room.

--
*Honk if you love peace and quiet.

Dave Plowman London SW
To e-mail, change noise into sound.

On Tue, 31 May 2005 23:05:38 +0100, "Mike" wrote:


"John Rumm" wrote in message
...
Just curiosity really, but on various occasions we have discussions here
that touch on the relative merits of the UK vs Euro style electrical
installations and fittings.

I had always thought that the UK regs and practices were amongst the
best, but perhaps not everyone agrees.

I don't agree for one. More importantly neither does almost every
electrical representative to the EU apart from the UK and Malta.

I think you're misinterpreting the meaning of the term "the best"
here. Never mind all this quality of form and function
how's-yer-father.
--
Regards,
Mike Halmarack

Drop the EGG to email me.

Mike wrote:
The view of a friend working for the EU directorate on this matter in the
mid-90s was roughly as follows :
The UK plug/socket is dangerous and probably causes more electrical fires
than any other piece of electrical equipment.

Poorly fitted *plugs* were certainly a major concern, but hasn't that
been addressed by plugs fitted on appliances before sale?

From what I've seen of European plugs they're not very substantial
either, those with cord outlets parallel to the pins are vulnerable to
being pulled out of sockets by the flex, and they're not polarised, so
their ES lampholders can have either contact live.

Similarly although the IEE have done well getting ring mains systems safe,
it is felt they rely on diversity too much for a modern house where there
may be large numbers of high current consumption devices often in separate
rooms where the users do not realise they are using a common ring. Also the
allowed practice of adding almost uncontrolled numbers of extra sockets to a
ring makes this worse. It is accepted that UK house make far less use of
electrical heaters than some other countries due to our cheap supply of gas
but pointed out that this won't last indefinitely.

However the ring was never designed for supplying fixed heating, and
if/when gas runs out we're going to be stuck for cheap electricity. For
safety reasons, if the main gas supply network fails, the bulk consumers
of gas (the electricity generators) are taken offline first, rather than
disconnecting domestic consumers.

The growth in number of sockets required is mostly consumer electronics,
which are low-current appliances. The ring was also never designed for
the large number of high-current kitchen appliances we see, but that is
being addressed by the provision of a separate circuit for the kitchen.

The proposed EU recommended wiring system consists of separate feeds to each
room with a small CU in that room with a breaker for lights and one for each
group of sockets/piece of equipment. The best CUs actually fit under the
light switch by the door which hinges up. A simple look round the room will
soon tell you if you are taking too much current (and the much more likely
to be correctly rated trip in that room blows anyway - not taking out the
whole house as in the UK). This is not to say that any particular country
in the EU follows this approach to the letter today.

Which still means (if you have 20A circuits) that some combinations of 2
x 3kW heaters, in some or other sockets on the same or different
circuits, will or won't work. The advantage of the ring circuit is the
flexibility it gives for using appliances without worrying which socket
they're plugged into. That's based on diversity, which is a sound
engineering principle.

One of the main advantages of the ring circuit, designed for the
post-war housing needs, was that it used less material than lots of
separate radials. Presumably the "proposed EU recommended wiring system"
is supported by European consumer unit and cable manufacturers, but I
doubt if by anyone else.

Why would this arrangement have a "much more likely to be correctly
rated trip"? And UK trips (do you mean MCB or RCD?) don't take out the
whole house in a correctly designed installation. Whole-house RCDs are
deprecated.

Owain

"Owain" wrote in message
t...

From what I've seen of European plugs they're not very substantial
either, those with cord outlets parallel to the pins are vulnerable to
being pulled out of sockets by the flex, and they're not polarised, so
their ES lampholders can have either contact live.

There was a new common design which was the same spacing but was a lot
better.


However the ring was never designed for supplying fixed heating,

But is used for such - hence the concern.


The growth in number of sockets required is mostly consumer electronics,
which are low-current appliances. The ring was also never designed for
the large number of high-current kitchen appliances we see, but that is
being addressed by the provision of a separate circuit for the kitchen.

But really this should be many individual circuits as used in Germany.



The advantage of the ring circuit is the
flexibility it gives for using appliances without worrying which socket
they're plugged into. That's based on diversity, which is a sound
engineering principle.

That's only fine if you can see the whole ring.


One of the main advantages of the ring circuit, designed for the
post-war housing needs, was that it used less material than lots of
separate radials. Presumably the "proposed EU recommended wiring system"
is supported by European consumer unit and cable manufacturers, but I
doubt if by anyone else.

Most German and Scandanavian housing built since the 80s meets it.



Why would this arrangement have a "much more likely to be correctly
rated trip"? And UK trips (do you mean MCB or RCD?) don't take out the
whole house in a correctly designed installation.

Umtil the late 80s, most UK houses had all lighting on one MCD.


Whole-house RCDs are deprecated.

But very commonplace and still being installed.

In article ,
"Mike" writes:

Whole-house RCDs are deprecated.

But very commonplace and still being installed.

They are part of the supplier's works in France.
However, they are rated at 500mA.

--
Andrew Gabriel

Mike wrote:
The growth in number of sockets required is mostly consumer electronics,
which are low-current appliances. The ring was also never designed for
the large number of high-current kitchen appliances we see, but that is
being addressed by the provision of a separate circuit for the kitchen.
But really this should be many individual circuits as used in Germany.

But why install 8 20A circuits just so you can plug a microwave and a
toaster anywhere in a kitchen, when one 30A circuit does just as well.
If the circumstances are such that a ring circuit is inappropriate then
a ring circuit is inappropriate - that doesn't mean that radial circuits
are always appropriate.

Owain

"Owain" wrote in message
...
Mike wrote:
The growth in number of sockets required is mostly consumer electronics,
which are low-current appliances. The ring was also never designed for
the large number of high-current kitchen appliances we see, but that is
being addressed by the provision of a separate circuit for the kitchen.
But really this should be many individual circuits as used in Germany.

But why install 8 20A circuits just so you can plug a microwave and a
toaster anywhere in a kitchen, when one 30A circuit does just as well.
If the circumstances are such that a ring circuit is inappropriate then
a ring circuit is inappropriate - that doesn't mean that radial circuits
are always appropriate.


Tell that to the Germans who still want radials all the way back to the
house's mains entry point. The use of radials to each room where another
small CU feed short radials was felt to be a good compromise by many and
matches commercial building installation practice in many EU countries.

Mike wrote:
"Owain" wrote in message

However the ring was never designed for supplying fixed heating,

But is used for such - hence the concern.

that doesnt create a convenience problem in 99% of cases, and doesnt
create a safety problem in any case. In large houses electricians are
quite capable of installing another ring to ensure things stay working
reliably. Just another non issue.


The growth in number of sockets required is mostly consumer electronics,
which are low-current appliances. The ring was also never designed for
the large number of high-current kitchen appliances we see, but that is
being addressed by the provision of a separate circuit for the kitchen.

But really this should be many individual circuits as used in Germany.

any reason? Our system works jus fine, and costs less. So no reason.


The advantage of the ring circuit is the
flexibility it gives for using appliances without worrying which socket
they're plugged into. That's based on diversity, which is a sound
engineering principle.

That's only fine if you can see the whole ring.

what does that mean?


Why would this arrangement have a "much more likely to be correctly
rated trip"? And UK trips (do you mean MCB or RCD?) don't take out the
whole house in a correctly designed installation.

Umtil the late 80s, most UK houses had all lighting on one MCD.

not at all. Are you British Mike?


Whole-house RCDs are deprecated.

But very commonplace and still being installed.

Only on TT systems where theyre a necessity. In those cases the main
RCD is time delayed, with 1 or more further RCDs downline to prevent
whole house blackouts.


NT

wrote in message
oups.com...
Mike wrote:
The advantage of the ring circuit is the
flexibility it gives for using appliances without worrying which
socket
they're plugged into. That's based on diversity, which is a sound
engineering principle.

That's only fine if you can see the whole ring.

what does that mean?

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.



Umtil the late 80s, most UK houses had all lighting on one MCD.

not at all. Are you British Mike?

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.

Mike wrote:

Umtil the late 80s, most UK houses had all lighting on one MCD.

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.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
John Rumm wrote:
Mike wrote:

Umtil the late 80s, most UK houses had all lighting on one MCD.

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.

Because in the average house it's all too easy to exceed the 5/6 amp limit
of a lighting circuit.

--


Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Mike wrote:
The growth in number of sockets required is mostly consumer
electronics, which are low-current appliances. The ring was also never
designed for the large number of high-current kitchen appliances we
see, but that is being addressed by the provision of a separate
circuit for the kitchen.

But really this should be many individual circuits as used in Germany.

But why? The UK system with fuse protection of the appliance etc in the
plug allows for much finer tuning of that protection. It might be that
there should be a wider range of fuses and types of fuse for plug top use,
but that wouldn't be too difficult.

--
*Support bacteria - they're the only culture some people have *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...

But really this should be many individual circuits as used in Germany.

But why? The UK system with fuse protection of the appliance etc in the
plug allows for much finer tuning of that protection. It might be that
there should be a wider range of fuses and types of fuse for plug top use,
but that wouldn't be too difficult.

When did Mr and Mrs Average UK Consumer 'tune the fuse'. It's 13A. Most
probably don't even know it comes in different values.

In article ,
Mike wrote:
However the ring was never designed for supplying fixed heating,

But is used for such - hence the concern.

Very, very few people will attempt to heat a full house with fan heaters,
etc. And even if they did in a large house with only one ring, even an old
rewirable fuse would blow before the wiring got overloaded to danger point.

--
*Reality is the illusion that occurs due to the lack of alcohol *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Mike wrote:
However the ring was never designed for supplying fixed heating,

But is used for such - hence the concern.

Very, very few people will attempt to heat a full house with fan heaters,
etc.

In the UK of course not. But in Sweden or other countries where electric
heating is the norm of course they will.

The proposed EU recommended wiring system consists of separate feeds to
each
room with a small CU in that room with a breaker for lights and one for
each
group of sockets/piece of equipment.

Oh joy. That sounds (a) cheap and (b) pretty.

The fact remains that the UK electrical system is statistically extremely
safe in comparison to the rest of the world.

Christian.

On Wed, 1 Jun 2005 09:48:31 +0100, "Christian McArdle"
wrote:

The proposed EU recommended wiring system consists of separate feeds to
each
room with a small CU in that room with a breaker for lights and one for
each
group of sockets/piece of equipment.

Oh joy. That sounds (a) cheap and (b) pretty.

The fact remains that the UK electrical system is statistically extremely
safe in comparison to the rest of the world.

Christian.

Are you saying that more people are killed or injured by electrical
energy in the rest of the world than in the UK?
The US penal system being a separate, special case..

--
Regards,
Mike Halmarack

Drop the EGG to email me.

Are you saying that more people are killed or injured by electrical
energy in the rest of the world than in the UK?
The US penal system being a separate, special case..

Per capita, yes.

Christian.

On Wed, 1 Jun 2005 10:08:01 +0100, "Christian McArdle"
wrote:

Are you saying that more people are killed or injured by electrical
energy in the rest of the world than in the UK?
The US penal system being a separate, special case..

Per capita, yes.

Christian.

Is that the result of a statistical survey?

--
Regards,
Mike Halmarack

Drop the EGG to email me.

On Tue, 31 May 2005 23:05:38 +0100, "Mike" wrote:

The UK plug/socket is dangerous and probably causes more electrical fires
than any other piece of electrical equipment.

Your friend was obviously a Frenchman. How many electrical fires in
the UK are caused by fixed wiring each year? How many deaths are
attributable to fires caused by fixed wiring?

What are the comparable figures for France and Germany?

In the 90s the rest of Europe
worked on a harmonised version of the IEC plug/socket only for the UK to
scupper it.

A Frenchman with no knowledge of history, how very unusual.

It is accepted that UK house make far less use of
electrical heaters than some other countries due to our cheap supply of gas
but pointed out that this won't last indefinitely.

By another Frenchman no doubt.

The proposed EU recommended wiring system consists of separate feeds to each
room with a small CU in that room with a breaker for lights and one for each
group of sockets/piece of equipment.

Oh good, a consumer unit in every room - how twee.

The best CUs actually fit under the
light switch by the door which hinges up.

One for the lights and one for the socket?

This is not to say that any particular country
in the EU follows this approach to the letter today.

How many do?

--
Peter Parry.
http://www.wpp.ltd.uk/

"Peter Parry" wrote in message
...
On Tue, 31 May 2005 23:05:38 +0100, "Mike" wrote:

The UK plug/socket is dangerous and probably causes more electrical fires
than any other piece of electrical equipment.

Your friend was obviously a Frenchman.

A Scot actually.

On Tue, 31 May 2005 23:05:38 +0100, "Mike" wrote:


The UK plug/socket is dangerous and probably causes more electrical fires
than any other piece of electrical equipment.

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.

In the 90s the rest of Europe
worked on a harmonised version of the IEC plug/socket only for the UK to
scupper it.

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"

Similarly although the IEE have done well getting ring mains systems safe,
it is felt they rely on diversity too much for a modern house where there
may be large numbers of high current consumption devices often in separate
rooms

Eh? Which "modern house" is this?


--
Peter Parry.
http://www.wpp.ltd.uk/

"Peter Parry" wrote in message
...

Similarly although the IEE have done well getting ring mains systems safe,
it is felt they rely on diversity too much for a modern house where there
may be large numbers of high current consumption devices often in separate
rooms

Eh? Which "modern house" is this?

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.

dennis@home wrote:

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.

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.

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.

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).

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

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

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

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.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
...
dennis@home wrote:

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.

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.

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.....


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.

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

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


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.


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

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.

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.

dennis@home wrote:
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.

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 wrote:
dennis@home wrote:

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.

My parents house, built in 1966, has electrical storage heating on a switched
(what would now be called Economy 7) night time, plus an afternoon boost, supply.

I've never paid it any attention but ISTR that each room with a storage heater
is fed by one 20A fuse. However the kitchen and living room both have two
heaters each, and I think these rooms are each fed by a 30A fuse.

The house is actually across two phases, so there are four fuse boxes,

Ring/Lights phase 1
Heating phase 1
Ring/Lights phase 2
Heating phase 2

The meter/fuse box area is rather large, my father built a cupboard around it
soon after moving in !

I wonder how much of any of that would be reg compliant these days ?

--
Mark
Please replace invalid and invalid with gmx and net to reply.

On Thu, 02 Jun 2005 14:03:04 GMT, "dennis@home"
wrote:


"Peter Parry" wrote in message

Eh? Which "modern house" is this?

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.

You forget temporal diversity. Moreover, a modern house (which was
what was specifically being referred to) would have a separate ring
for kitchen and downstairs.

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

Why has it proven to be so much safer than continental practice then?

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

How will this improve safety?

--
Peter Parry.
http://www.wpp.ltd.uk/