Jerry wrote:
"Sidney Endon-Lee" wrote in message
...
:
:
: Jerry wrote:
: "harry" wrote in message
:
...
: On 1 Sep, 21:28, "alexander.keys1"

: wrote:
:
: snip
: : Ring circuits and fused plugs were introduced in the UK
: : to save copper etc. in the post-WW2 rebuilding programme,
: : they have a number of disadvantages.
:
: : Which are?
:
: I take it that you have never come across the bolt being used
as
: a 'fusible' link within the a Bullshi... sorry BS1363 plug
that
: is feeding a device that draws 3amp via a similar rated
length
: of flex.
:
: I take it that you have never come across the situation were
an
: faulty appliance fails to blow the fusible wire within the
: Bull****... sorry BS1363 plug but trips out the much more
: sensitive CB on the panel, taking out all other devices
connected
: to that circuit (which in a house can be the entire power
: circuit.
:
: The ONLY two advantage of ring circuits is installation cost
and
: smaller size of fuse/CB panel.
: --
: Regards, Jerry.
:
: Jerry,
:
: I am happy for you that you are so certain. I suggest you
practise
: 'thinking around the problem' a little more,

Who says I have not 'though through these problems', perhaps that
IS why I have come to the conclusions I have...

I say, and it is self-evident from your answers so far.

and also clarifying your
: thinking. There are benefits and disadvantages to ring and spur
: circuits;

Err, spur circuits are supplied from ring circuits, thus they are
one and the same, duh!

Apologies, for 'spur', read 'radial'.


and benefits and disadvantages to fuses and circuit
: breakers; and benefits and disadvantages to having fuses in
plug-tops
: or at the consumer unit. Different choices will be better in
different
: situations, and it is well worth understanding that. It is not
the
: case that one method is unambiguously better than all the
others in
: all situations.
:
: To give an example: generally, domestic lighting circuits are
not ring
: circuits, even though the circuit serving sockets frequently
is.

Most of the domestic lighting circuits I've ever come across of
based on looping in and out of ceiling (rose) fittings, thus one
faulty fitting will trip all the lights on that circuit, hence
why there will/should always be two lighting circuits (one
usually for stair-well lighting) protected independently of each
other BECAUSE the design failings of loop-in, loop-out circuits
are recognised and accepted - one out, all out, so to speak!...

You didn't answer the question: perhaps you are confusing 'loop' and
'ring'.

You
: might like to reflect on why that is. You may also like to
reflect on
: why it is not uncommon for kitchens to have a ring circuit
separate
: from the other circuits in a dwelling; and why immersion
heaters are
: usually put on their own spur. And to start things off, what do
you
: think the function of a plug-top fuse is?
:

Perhaps you should do the reflecting, WHY is it usual to install
such circuits, perhaps if you actually thought through the actual
issues then you would realise that you have made a very good
argument against ring circuits!
--
Regards, Jerry.

I think you do need to take things a bit more slowly, and think deeply
about your answers. Just because you do things in a certain way,
possibly the way you were taught, doesn't necessarily make it the
right way. You may, of course, be correct, but nothing you have said
has convinced me you actually understand what you are doing.

Jerry wrote:
"Bob Eager" wrote in message
...
: On Thu, 02 Sep 2010 10:33:19 +0100, Jerry wrote:
:
: taking out all other devices connected to that circuit
(which
: in a house
: : can be the entire power circuit.
: :
: : Pretty badly designed if it's the ONLY power circuit - our
house has
: five
: : rings.
: :
:
: Only if you are being a pedantic fool and taking the meaning
of the word
: "House" to me a multi floor dwelling rather than the more
usual generic
: meaning of the word as a place were people live. Anyway, even
if there
: was multiple ring circuits one faulty device will still take
out all
: devices being powered from that circuit rather than just the
one or two
: that would be on a radial circuit.
:
: No pedantry - you don't seem to understand at all.

Whhhoooossshhhh, unless you are makintg a very good case for
radial circuits in small houses, flats and bungellows!

:
: Never mind - it'll ne OK when you finish Key Stage 2.

Just because you are still at Key Stage 1, repeating,
unquestioned, all your are being told parrot fashion, you think
everyone else is...
just because you have fished stage 2, don't assume that those of us with
degrees in electrical engineering and a lifetime of dealing with
electrical circuits haven't thought about it just as much as you have,
and don't need to be patronised.

The benefit of ring final circuits is...
1) Power is shared between two "legs" each of which must have a
Corrected Current Carrying Capacity of 20A. Since most installs have
FTE 2.5mm under capping/direct the two legs are individually often
closer to a 27A rating so it is better than it appears.
2) CPC has 2 routes and twice the cross sectional area, which if into
separate terminals is actually rather useful against "no CPC".
3) Prior to 17th where final circuit length was often limited by earth
fault loop impedance having two CPC meant you could go substantially
further than say a radial.
4) Ring final circuit could achieve a 32A final circuit using 2.5mm
rather than more expensive 4.0mm which suffers the afliction of having
only a 1.5mm CPC when TBH it could have had say 2.0mm.

The disadvantage of ring final circuits is...
1) Power draw may all be at one end of the ring, which is to say an
imbalanced ring exists, for example 24A is supplied by one leg (above
its 20A min rating) and only 8A in the other leg. It is here that ring
finals have less of a leg to stand on.
2) Physical layout for a ring can actually be disadvantageous with
solid floors, inaccessible ceiling voids etc, because you have twice
as many cables as with a radial
3) 32A ring final circuit can tempt installers to fit just one such
final circuit to a house, when it would be much wiser to have say 3 re
upstairs, downstairs & kitchen.

Since I have solid floors, inaccessible ceiling voids, odd roof shapes
and sloping ceilings, steel beams & chimney's everywhere etc, I much
prefer 20A radials on a per room basis and 32A radial with 4mm in a
kitchen. The original install had 32A radials on a per room basis
including kitchen, however it is hard to justify 32A on a bedroom -
that is over 3x 2kW fan heaters.


Lighting, loop-in does suffer from one lost supply, lose everything.
You can use loop-in light switch which might be useful if future
technologies require a neutral at the switch.

I designed a loop-in switch off a 2G accessible jn-box just below the
ceiling, that way each room gets a supply to the switch (with neutral)
and then switch to light fitting. If a room goes bad you can simply
disconnect it quickly, test it, replace it - whilst other rooms are
unaffected. Makes it easy to migrate from an old multi-junction box
(19 for up & down lights) to a zero junction box system one-by-one
with a MK Grid 2-module DP switch for "old lights" & "new lights" at
the CU.

Lighting can be wired in a ring and often is industrially re 10A &
even 16A lighting circuits, not so common domestically though. It
provides some benefits like socket rings though. RCD reduce the need
to get EFLI within 80% limit although personally I prefer that it is
(TT rely on RCD critically for disconnect tho anyway).

js.b1 wrote:

[A very informative, long reply]

Thanks js.b1. That's the kind of reply I was hoping Jerry might come
up with.

Sid

js.b1 wrote:
3) Prior to 17th where final circuit length was often limited by earth
fault loop impedance having two CPC meant you could go substantially
further than say a radial.


For a type B MCB then voltage drop was the limiting factor for both rings
and radials prior to the 17th ed. Under the 17th with a 5% volt drop allowed
on sockets you can go even further.

But the word "further" is where the big difference between rings and radials
matters.

I make good use of spurs for those far away sockets that would eat up lots
of the maximum length of 2.5T&E if I was to include them on the ring.

--
Adam

Oh, one other disadvantage (in theory) of 32A ring and indeed 32A
radial is that a 2G socket is only capable of 19.5A continuously -
somewhat less than 2x 13A fuse protection and somewhat less than the
32A fuse/circuit breaker.

I say in theory because running 19.5A continuouslly on a 2G socket is
quite difficult. Even twin 2kW fan heaters are only 20A and are very
likely to cycle on a thermostat. I guess in a warehouse it is
possible, but that is not domestic. Tumbler dryer is a few hours at
most, kettle minutes, toaster minutes. A commercial kitchen is one
location perhaps.

On 2 Sep,
"Jerry" wrote:

Anyway, even if there was multiple ring circuits one faulty
device will still take out all devices being powered from that
circuit rather than just the one or two that would be on a radial
circuit.

One faulty device will just take out the fuse in the plug top.

--
B Thumbs.

On Thu, 02 Sep 2010 14:04:40 +0100, John Rumm wrote:


No offence Jerry, but this is a load of ill thought out twaddle.

snipped excellent reply

What an elegantly crafted reply!


--
The Wanderer

Faith is a gift from your God
Religion is a gift from the Devil

On 2 Sep, 09:14, "Jerry" wrote:
"harry" wrote in message

...
On 1 Sep, 21:28, "alexander.keys1"
wrote:

snip
: Ring circuits and fused plugs were introduced in the UK
: to save copper etc. in the post-WW2 rebuilding programme,
: they have a number of disadvantages.

: Which are?

I take it that you have never come across the bolt being used as
a 'fusible' link within the a Bullshi... sorry BS1363 plug that
is feeding a device that draws 3amp via a similar rated length
of flex.

I take it that you have never come across the situation were an
faulty appliance fails to blow the fusible wire within the
Bull****... sorry BS1363 plug but trips out the much more
sensitive CB on the panel, taking out all other devices connected
to that circuit (which in a house can be the entire power
circuit.

The ONLY two advantage of ring circuits is installation cost and
smaller size of fuse/CB panel.
--
Regards, Jerry.

No I haven't. I 've been an electrician/electrical engineer for forty
years. Including a spell repairing domestic appliances.
I have seen aluminium foil wrapped round a fuse. I have seen the 13a
fuse left in the plug when it should have been replaced with a smaller
one. But it only takes us back to what they have in America or the
continent.

It takes a lot of effort to create a solid metal replacement for a
fuse. Easier to get a fuse.

On 2 Sep, 10:33, "Jerry" wrote:
"Bob Eager" wrote in message

...
: On Thu, 02 Sep 2010 09:14:39 +0100, Jerry wrote:
:
: I take it that you have never come across the bolt being used
as
: a 'fusible' link within the a Bullshi... sorry BS1363 plug
that is
: feeding a device that draws 3amp via a similar rated length
of flex.
:
: And this never happens with other fuses? Of course it does.
Anyway, it's
: quite hard to use *abol;t with many modern moulded plugs.

********, it only need metal the same dia of the BS fuse, rather
than having to dismantle a distribution board, take out a CB and
replace even with a higher rated unit never mind a solid bridge.

:
: And no, I haven't come across it. Anyone who does that has
probably done
: lots of other dangerous things too.

Your point being what, exactly?...

:
: I take it that you have never come across the situation were
an faulty
: appliance fails to blow the fusible wire within the
Bull****... sorry
: BS1363 plug but trips out the much more sensitive CB on the
panel,
: taking out all other devices connected to that circuit (which
in a house
: can be the entire power circuit.
:
: Pretty badly designed if it's the ONLY power circuit - our
house has five
: rings.
:

Only if you are being a pedantic fool and taking the meaning of
the word "House" to me a multi floor dwelling rather than the
more usual generic meaning of the word as a place were people
live. Anyway, even if there was multiple ring circuits one faulty
device will still take out all devices being powered from that
circuit rather than just the one or two that would be on a radial
circuit.
--
Regards, Jerry.

You are in cloud cuckoo land. A faulty appliance virtually never
trips the 32a circuit breaker. You talk as if it did every time.
The plug fuse blows in 99.999% of cases. There are three sorts of
circuit breakers available with different time characteristics anyway.
When we had fuses in the control panel, it was a 30a fuse. The reason
the CB is 32a is exactly to forstall the non-existant problem in your
brain.
We are talking of a sytem that has been in use for sixty years. Any
snags have long been ironed out.
The system is cheap to install and extend, safer than American and
European systems, more flexible and efficient.

On 02/09/2010 17:32, harry wrote:

It takes a lot of effort to create a solid metal replacement for a
fuse. Easier to get a fuse.

OP here,

Having just got off the phone to EDF Energy Networks (EDN) who said that
they were sending a repair team over after the emergency, but have now
cancelled them (2 days running now, after lame excuses about them being
engaged on other jobs) - I'm rather tempted to find the solid metal
replacement (for neutral) and probably more sensibly uprate their fuses
(60A = 2 parallel bits of 30A fuse wire?), after they are now saying
their eventual fix upgrade will be chargable.

What other choice? This is turning into a mess :-(

--
Adrian C

Having just got off the phone to EDF ...

Don't take any s*** from EDF - they make Scrooge look like a
philanthropist. They really are money-grubbing b*******.

Demand that they send an engineer round to asses the work required
(surveys for cost estimates aren't charged) - making it very clear
that a professional electrician has warned you that their supply side
is in a dangerous state.

Then if they try to quote a charge for the work - print off and send
them the pdf links given by another poster here.

On Thu, 02 Sep 2010 18:18:11 +0100, Adrian C wrote:

On 02/09/2010 17:32, harry wrote:

It takes a lot of effort to create a solid metal replacement for a
fuse. Easier to get a fuse.

OP here,

Having just got off the phone to EDF Energy Networks (EDN) who said that
they were sending a repair team over after the emergency, but have now
cancelled them (2 days running now, after lame excuses about them being
engaged on other jobs)

It happens. I recollect one job that went wrong four or five times because
of staff being diverted onto major faults. (And that was after management
had promised the person it would be done!)

- I'm rather tempted to find the solid metal
replacement (for neutral) and probably more sensibly uprate their fuses
(60A = 2 parallel bits of 30A fuse wire?),

Definitely not. You don't want to finish up as an accident statistic.
Without getting too technical, but if you happen to short out L & N, the
potential amount of energy there is far more than you wold be used to in a
normal domestic situation, and there's every possibility that you could
electrocute yourself. I've had to attend one or two electrocutions some
years ago, not pleasant.

after they are now saying
their eventual fix upgrade will be chargable.

Whoa there. 'Phone them back again. Tell them their equipment - rewireable
fuses that date back perhaps 60-70 years - does not meet the requirements
of paragraphs 3, 7, & 34 of the The Electricity Safety, Quality and
Continuity Regulations 2002. Ask them why are they charging you to correct
work that should have been done by them some 20 years or more ago.

The document is here

http://www.legislation.gov.uk/uksi/2002/2665/made

Tell them you will take it to OFGEM if they won't make arrangements to
carry out the work - that's usually enough to push 'em into action.

http://www.ofgem.gov.uk/Pages/OfgemHome.aspx


Sadly their response is indicative of what has happened within the industry
since privatisation, when they try to get the customer to pay for
everything......





--
The Wanderer

Caffeine isn't addictive as long as you keep taking it.

"Sidney Endon-Lee" wrote in message
...
:
: Jerry wrote:

snipped
:
: Who says I have not 'though through these problems', perhaps
that
: IS why I have come to the conclusions I have...
:
: I say, and it is self-evident from your answers so far.

Yes, that I have given the issues thought whilst all you appear
to have done is read the building code/electrical regs - no doubt
electricians in the US also blindly defend (their) *accepted*
ways of "doing it"...

:
: and also clarifying your
: : thinking. There are benefits and disadvantages to ring and
spur
: : circuits;
:
: Err, spur circuits are supplied from ring circuits, thus they
are
: one and the same, duh!
:
: Apologies, for 'spur', read 'radial'.
:
:
: and benefits and disadvantages to fuses and circuit
: : breakers; and benefits and disadvantages to having fuses in
: plug-tops
: : or at the consumer unit. Different choices will be better
in
: different
: : situations, and it is well worth understanding that. It is
not
: the
: : case that one method is unambiguously better than all the
: others in
: : all situations.
: :
: : To give an example: generally, domestic lighting circuits
are
: not ring
: : circuits, even though the circuit serving sockets
frequently
: is.
:
: Most of the domestic lighting circuits I've ever come across
of
: based on looping in and out of ceiling (rose) fittings, thus
one
: faulty fitting will trip all the lights on that circuit,
hence
: why there will/should always be two lighting circuits (one
: usually for stair-well lighting) protected independently of
each
: other BECAUSE the design failings of loop-in, loop-out
circuits
: are recognised and accepted - one out, all out, so to
speak!...
:
: You didn't answer the question: perhaps you are confusing
'loop' and
: 'ring'.

No, that is what you seem to be doing, or you simply do not
understand the physical wiring schemes. There is very little
*schematic* difference in how a feed wires for lighting circuit
loop in and out of the ceiling (rose) fitting and how the feed
wires on a ring circuit loop in and out of sockets, the only
differance is the lack of one set of conductors in the lighing
circuit that would complete the 'ring' (and there is no techical
reason why that conductor couldn't be pressent, other than added
cost on instalation).

Ring Circuit;
[CB1]==[SKT]==[SKT]==[SKT]==[SKT]==[CB1]


Lighting Circuit;
[CB2]==[CRF]==[CRF]==[CRF]==[CRF]~~[CB2]

SKT = Socket
CRF = Ceiling rose/light fitting

Spurs and switch drops are incidental [1] to how the *power* is
delivered to the load, the missing conductor shown as ~~ is all
that preventing the lighting circuit being a true 'ring' and if
it was present the circuit would still work, still be protected
and might even theoretically allow a smaller cross sectional
conductor to be used.

[1] spurs are not always present whilst some light fittings /
lighting instillations are devoid of individual switch drops

:
: You
: : might like to reflect on why that is. You may also like to
: reflect on
: : why it is not uncommon for kitchens to have a ring circuit
: separate
: : from the other circuits in a dwelling; and why immersion
: heaters are
: : usually put on their own spur. And to start things off,
what do
: you
: : think the function of a plug-top fuse is?
: :
:
: Perhaps you should do the reflecting, WHY is it usual to
install
: such circuits, perhaps if you actually thought through the
actual
: issues then you would realise that you have made a very good
: argument against ring circuits!
:
: I think you do need to take things a bit more slowly, and think
deeply
: about your answers. Just because you do things in a certain
way,
: possibly the way you were taught, doesn't necessarily make it
the
: right way. You may, of course, be correct, but nothing you have
said
: has convinced me you actually understand what you are doing.

Whilst nothing that you have said suggests that you actually
understand anything other than what the regs say...
--
Regards, Jerry.

"The Natural Philosopher" wrote in message
...
: Jerry wrote:
: "Bob Eager" wrote in message
: ...

snip
: :
: : Never mind - it'll ne OK when you finish Key Stage 2.
:
: Just because you are still at Key Stage 1, repeating,
: unquestioned, all your are being told parrot fashion, you
think
: everyone else is...
:
: just because you have fished stage 2, don't assume that those
of us with
: degrees in electrical engineering and a lifetime of dealing
with
: electrical circuits haven't thought about it just as much as
you have,
: and don't need to be patronised.
:

Just because you have learn to act like parrots, repeating
ad-nausea what your owners tell you, rather than use your brain
cells... It was people like you who held industrial
manufacturing/development in the UK back for so long, allowing
others to have the blue "skies thinking" that turned much of the
UK Plc into not much more than assembly lines at best and
importing/warehousing agents at worst.
--
Regards, Jerry.

"John Rumm" wrote in message
...
: On 02/09/2010 10:33, Jerry wrote:
:
: Only if you are being a pedantic fool and taking the meaning
of
: the word "House" to me a multi floor dwelling rather than the
: more usual generic meaning of the word as a place were people
: live. Anyway, even if there was multiple ring circuits one
faulty
: device will still take out all devices being powered from
that
: circuit rather than just the one or two that would be on a
radial
: circuit.
:
: Although I suspect that Jerry has not realised it, his beef
seems to be
: with fused plugs, since he has actually highlighted nothing of
relevance
: to circuit topology.

Yes, and I have said that both radial and ring circuits have both
advantages and disadvantages.

Plug fuses can be abused (as can rewireable fuses
: in consumer units), however in reality this much less of a
problem that
: might be imagined.

But we are talking about (theoretical) risks, allowing the
ignorant to defeat final protection with not much more than a
kitchen or pen knife and thus compete for a "Darwin Award" has a
very much higher risk factor than many of the risk that the regs
are obsessed with now!

Most appliances are designed to be sold all over the
: world, and hence will usually have a flex that is capable of
surviving
: faults with only 16A head end protection (as would be common in
some
: countries),

Not so sure, whilst many appliances are sold all over the world,
since the UK law has required the pre-fitment of BS1363 plugs
complete with the correctly rated BS fuse many appliances now
come with power leads not only with moulded on plugs but the lead
rated to the fitted fuse IYSWIM.

hence the fact that someone might substitute a 13A fuse in
: place of a 3A is not likely to be a problem with most
appliances. There
: is the remaining issue that one could substitute a solid object
for a
: fuse, but that does not appear to be something that happens
regularly.
: Quite possibly because it is very rare for plug fuses to blow
in the
: first place.

How do know the practice is rare or not, only when something goes
dramatically wrong will the miss-use ever become apparent and if
protecting an appliance with a grossly over-rated device (15A or
even 30A instead of 3A) isn't really that much of a problem then
the rational behind the original design of the BS1364 plug/socket
must be in question! Also any appliance that does need careful
protection should perhaps have to have a 'tools-only' accessible
internal fuse anyway?

:
: The absence of a plug fuse requires that the protective device
at the
: head end of the circuit can clear not only overloads of the
whole
: circuit, but also faults that may occur in light weight
appliance
: flexes.

But that IS the way things are going anyway, hence stories of
RCBs tripping out because someone has pluged in a doggy table
lamp in one room and taking out the supply to someone using a
computer in another and thus their unbacked up work - and don't
suggest that they should have had the computer on a differant
ring circuit, "Average Joe" and his family use what the
builders/electritains have installed.

This second requirement places significant restraints on the
: circuit as a whole, and drastically limits the total power
supply
: capability. Hence the proliferation of inflexible[1] low
current rated
: circuits you get in places like the US.
:
: [1] Think about a kitchen / utility room with tumble drier,
dish washer,
: and washing machine. That could represent 8kW of load -
although it
: would be diverse - the chances of all three being in use at one
time is
: relatively small, and the presence of thermostatic controls on
the
: heaters will mitigate further. These could safely be power on
one 32A
: ring circuit, but would probably require three 16A or 20A
radials to do
: the same job.
:

Indeed, or perhaps even a sub-main feeding a sub-board. Also,
remember if these appliances/utility room is feed via it's own
ring circuit this requires two of the two out of the three cable
runs needed for the radials anyway, cost savings will be minimal
and thus I would prefer the redundancy given by radial circuits,
also radial circuits and 15amp unfused plugs would remove the
issue of either BS1363 plugs stuck behind these difficult to move
appliances, plug and sockets being fitted in cupboards, trailing
leads or hard-wired flex outlet plates.

Most owners don't care how many, or indeed the cross section of
such, wires have been installed in a building (even the fitment
of 5amp lighting points in the wall), what they do notice is
price (of new house or re-wiring a old house), so the choice of
ring vs. radial circuit comes down to cost at the end of the day,
not really the technical pros and cons of each.
--
Regards, Jerry.

"Brian D" wrote in message
...
: On 2 Sep,
: "Jerry" wrote:
:
: Anyway, even if there was multiple ring circuits one faulty
: device will still take out all devices being powered from
that
: circuit rather than just the one or two that would be on a
radial
: circuit.
:
: One faulty device will just take out the fuse in the plug top.
:

In theory, in practice a wire fuse (as fitted to the BS1363 plug)
might not melt before a (R)CB trips...
--
Regards, Jerry.

On 02/09/2010 19:06, The Wanderer wrote:

- I'm rather tempted to find the solid metal
replacement (for neutral) and probably more sensibly uprate their fuses
(60A = 2 parallel bits of 30A fuse wire?),

Definitely not. You don't want to finish up as an accident statistic.
Without getting too technical, but if you happen to short out L& N

I'm really not going to do that ;-)


Whoa there. 'Phone them back again. Tell them their equipment - rewireable
fuses that date back perhaps 60-70 years - does not meet the requirements
of paragraphs 3, 7,& 34 of the The Electricity Safety, Quality and
Continuity Regulations 2002. Ask them why are they charging you to correct
work that should have been done by them some 20 years or more ago.

The document is here

OK, 9am tomorrow I'm going to warm up their 'general enquiry' phone
wires a bit.

--
Adrian C

"harry" wrote in message
...

: You are in cloud cuckoo land.

Well, perhaps, but then I live in the real world and not that
perfect world that you seem to inhabit, were if something is
meant to happen it always will, like all company supply neutral
fuses having been removed by the mid 1980s or that the BS1364
plug will always have the correct fuse installed, or indeed any
fuse...

snip
: The [UK] system is cheap to install and extend,
: safer than American and European systems, more
: flexible and efficient.

The only true statement in the above is the words "cheap to
install". The problem with North American system is more to do
with quality (of the components used) rather than the design of
the circuits, same is true of European systems added to issues of
workmanship [1]. How is someone in the UK being able to protect
their 3amp table lamp via a bolt (or indeed a 13amp fuse) in the
BS1363 plug and the 20 to 30A CB at the D-board any more safe
than someone in either the US or EU plugging the same 3amp table
lamp into a wall socket protected at ~15amp CB at the D-board?

[1] and shoddy workmanship is also a problem in the UK also
--
Regards, Jerry.

"John Rumm" wrote in message
...
: On 02/09/2010 09:14, Jerry wrote:
: wrote in message
:
...
: On 1 Sep, 21:28,
: wrote:
:
: snip
: : Ring circuits and fused plugs were introduced in the UK
: : to save copper etc. in the post-WW2 rebuilding programme,
: : they have a number of disadvantages.
:
: : Which are?
:
:
: No offence Jerry, but this is a load of ill thought out
twaddle.
:
: I take it that you have never come across the bolt being used
as
: a 'fusible' link within the a Bullshi... sorry BS1363 plug
that
: is feeding a device that draws 3amp via a similar rated
length
: of flex.
:
: Being able to abuse a fuse in a plug is not a fault of ring
circuit.

No, it's the fault of the regs that allow the design of the
circuit and/or the hardware.

The
: circuit in question could be a radial, and the circumstance
would be no
: more desirable.

Not so, radial circuits would be/are more tightly protected, a
15amp CB rather than the 20 to 30 amp CB fitted to ring circuits.

:
: I take it that you have never come across the situation were
an
: faulty appliance fails to blow the fusible wire within the
: Bull****... sorry BS1363 plug but trips out the much more
: sensitive CB on the panel, taking out all other devices
connected
: to that circuit (which in a house can be the entire power
: circuit.
:
: Again, this is nothing to do with circuit topology. As a
general rule,
: overload related problems are more likely to blow the plug
fuse, and
: hence result in "perfect" discrimination (i.e. the only device
losing
: power is the faulty one). Fault (i.e. short circuit related)
may
: occasionally trip a circuit breaker in the consumer unit.
However again,
: this has nothing to do with circuit topology, the same could
happen with
: a radial.
:
: If you follow US practice for example where the only protection
is at
: the origin of the circuit, then you can be sure to de-energise
the whole
: circuit for all faults (either than or have to work out how to
get at an
: internal appliance fuse).

Oh, so taking out just a room rather than a floor (as is usual
with a ring circuit) is worse?!

:
: The ONLY two advantage of ring circuits is installation cost
and
: smaller size of fuse/CB panel.
:
: In fact neither of these are true now. Installation cost, when
: installing from scratch is not significantly different.

But was when the UK ring circuit was first designed and
introduced, now the ring has just become the day-facto standard
and is often installed without (prior) thought.

Also remember
: than in the UK we can have 32A radial circuits if required, so
there is
: no particular advantage in reducing the number of ways in a
consumer
: unit either.

But the use of ring circuits HAS resulted in a reduction in the
number of ways in the average domestic D-board.

:
: It is important to realise that what started as a way of saving
copper
: after the war, has been refined and improved over the years, to
what we
: have now, which is a circuit that is very well suited to modern
patterns
: of use.

Has it been refined, *circuit* protection might have been refined
and this has allowed a refinement in conductor size etc. but the
circuit design and end appliance protection hasn't been refined
that much if at all.

The ring circuit is also well suited to provision of power for
: "diverse" loads - i.e. large numbers of appliances can be
provided for
: over a large floor area, and also higher power devices can be
included
: in that mix without fear or overloading a circuit.

Err, one can only use, either, the number of appliances up to the
total number and rating of sockets or the total rating of the
circuit, the same is true of radial circuits. 'Diversity' is
applicable to the loading of radial circuits as it is to ring
circuits.

Alternatively they
: also cope with applications where many high power appliances
are used in
: proximity such as kitchens, where the ability to provision for
7.2kW of
: load without needing unmanageable cables sizes is a great
advantage.

Sorry but that sounds somewhat like a straw-man argument, how
many domestic kitchens would draw that sort of (non "diverse")
load [1] and if we are talking about industrial installations
then running radial circuits via a sub-main and sub-board could
be as convenient, with the added advantage of appliance
redundancy - not having the one out all out total failure of a
ring circuit tripping out.

[1] and as has been pointed out elsewhere, if 7.2KW of non
diverse load does need to be supplied then 2/3rds of the cabling
needed for three radial circuits would be needed in a dedicated
ring circuit anyway.

:
: You have a circuit that behaves better under most of the common
failure
: modes in circuit wiring (i.e. high resistance or broken
conductors), and
: retains higher levels of protection under most of these failure
modes.

In other words, what you seem to be saying is, the ring circuit
is good at masking (possibly) fatal faults, such as a
disconnected conductor, thus the circuit has the same load on a
single 2.5mm T&E rather than sharing the load between two sets of
such conductors...

:
: For a full description see:
:
http://wiki.diyfaq.org.uk/index.php?..._circuit_types
:
: Ring circuits typically have lower earth fault loop impedances
as well,
: result in quicker clearing of faults.
:

Why should that be, and what would need to be changed in a radial
circuit spec to mirror the results found in ring circuits?
--
Regards, Jerry.

"The Wanderer" wrote in message
.. .
: On Thu, 02 Sep 2010 14:04:40 +0100, John Rumm wrote:
:
:
: No offence Jerry, but this is a load of ill thought out
twaddle.
:
: snipped excellent reply
:
: What an elegantly crafted reply!
:

Another unthinking parrot, "the regs say such and such, so that
is that then"...

"harry" wrote in message
...

snip
:
: It takes a lot of effort to create a solid metal replacement
for a
: fuse.

No it doesn't, not for a BS1363 plug, just a hacksaw and a
suitable bit of metal (such as the common 8mm bolt found in so
many cheapo DIY packs of 'essential' DIY fixings as sold by the
sheds, TV channels and even supermarkets. Bloody idiots for doing
it, but that is how easy it is. :~((

: Easier to get a fuse.

Not if the frecking appliance keeps 'popping' the highest
available fuse...
--
Regards, Jerry.

On Thu, 2 Sep 2010 21:56:14 +0100, Jerry wrote:

"The Wanderer" wrote in message
.. .
: On Thu, 02 Sep 2010 14:04:40 +0100, John Rumm wrote:
:
:
: No offence Jerry, but this is a load of ill thought out
twaddle.
:
: snipped excellent reply
:
: What an elegantly crafted reply!
:

Another unthinking parrot, "the regs say such and such, so that
is that then"...

Whatever you say, Jerry.

I'm minded of the proud mum watching her army son marching with all his
fellow squaddies. 'Ooh look! My son's the only one in step......'



--
The Wanderer

Inertia keeps me going!

On 2 Sep, 18:18, Adrian C wrote:
On 02/09/2010 17:32, harry wrote:

It takes a lot of effort to create a solid metal replacement for a
fuse. Easier to get a fuse.

OP here,

Having just got off the phone to EDF Energy Networks (EDN) who said that
they were sending a repair team over after the emergency, but have now
cancelled them (2 days running now, after lame excuses about them being
engaged on other jobs) - I'm rather tempted to find the solid metal
replacement (for neutral) and probably more sensibly uprate their fuses
(60A = 2 parallel bits of 30A fuse wire?), after they are now saying
their eventual fix upgrade will be chargable.

What other choice? This is turning into a mess :-(

--
Adrian C

You are just talking to a phone monkey. You need to talk to one of
their engineers. Get on the phone, tell the phone monkey to F****
off, you need to speak to their supervisor. Tell them someone has had
an electric shock. Tell them you have contacted the Daily Mail and a
reporter id coming round.
Get the idea? You need to get nasty with the *******s right?

On 2 Sep, 19:18, "Jerry" wrote:
"The Natural Philosopher" wrote in ...: Jerry wrote:

: "Bob Eager" wrote in message
: ...

snip
: :
: : Never mind - it'll ne OK when you finish Key Stage 2.
:
: Just because you are still at Key Stage 1, repeating,
: unquestioned, all your are being told parrot fashion, you
think
: everyone else is...
:
: just because you have fished stage 2, don't assume that those
of us with
: degrees in electrical engineering and a lifetime of dealing
with
: electrical circuits haven't thought about it just as much as
you have,
: and don't need to be patronised.
:

Just because you have learn to act like parrots, repeating
ad-nausea what your owners tell you, rather than use your brain
cells... It was people like you who held industrial
manufacturing/development in the UK back for so long, allowing
others to have the blue "skies thinking" that turned much of the
UK Plc into not much more than assembly lines at best and
importing/warehousing agents at worst.
--
Regards, Jerry.

99% of major innovation has come from the UK (or Germany) The Yanks
invented nothing new.
I have walked round construction sites in America. It's like going
back to the 1920s. And the standard of work was total crap.
Your wiring systems date from the early 20th century. Your plumbing/
heating systems are even worse.

On 2 Sep, 20:48, "Jerry" wrote:
"John Rumm" wrote in message

...
: On 02/09/2010 10:33, Jerry wrote:
:
: Only if you are being a pedantic fool and taking the meaning
of
: the word "House" to me a multi floor dwelling rather than the
: more usual generic meaning of the word as a place were people
: live. Anyway, even if there was multiple ring circuits one
faulty
: device will still take out all devices being powered from
that
: circuit rather than just the one or two that would be on a
radial
: circuit.
:
: Although I suspect that Jerry has not realised it, his beef
seems to be
: with fused plugs, since he has actually highlighted nothing of
relevance
: to circuit topology.

Yes, and I have said that both radial and ring circuits have both
advantages and disadvantages.

*Plug fuses can be abused (as can rewireable fuses
: in consumer units), however in reality this much less of a
problem that
: might be imagined.

But we are talking about (theoretical) risks, allowing the
ignorant to defeat final protection with not much more than a
kitchen or pen knife and thus compete for a "Darwin Award" has a
very much higher risk factor than many of the risk that the regs
are obsessed with now!

Most appliances are designed to be sold all over the
: world, and hence will usually have a flex that is capable of
surviving
: faults with only 16A head end protection (as would be common in
some
: countries),

Not so sure, whilst many appliances are sold all over the world,
since the UK law has required the pre-fitment of BS1363 plugs
complete with the correctly rated BS fuse many appliances now
come with power leads not only with moulded on plugs but the lead
rated to the fitted fuse IYSWIM.

*hence the fact that someone might substitute a 13A fuse in
: place of a 3A is not likely to be a problem with most
appliances. There
: is the remaining issue that one could substitute a solid object
for a
: fuse, but that does not appear to be something that happens
regularly.
: Quite possibly because it is very rare for plug fuses to blow
in the
: first place.

How do know the practice is rare or not, only when something goes
dramatically wrong will the miss-use ever become apparent and if
protecting an appliance with a grossly over-rated device (15A or
even 30A instead of 3A) isn't really that much of a problem then
the rational behind the original design of the BS1364 plug/socket
must be in question! Also any appliance that does need careful
protection should perhaps have to have a 'tools-only' accessible
internal fuse anyway?

:
: The absence of a plug fuse requires that the protective device
at the
: head end of the circuit can clear not only overloads of the
whole
: circuit, but also faults that may occur in light weight
appliance
: flexes.

But that IS the way things are going anyway, hence stories of
RCBs tripping out because someone has pluged in a doggy table
lamp in one room and taking out the supply to someone using a
computer in another and thus their unbacked up work - and don't
suggest that they should have had the computer on a differant
ring circuit, "Average Joe" and his family use what the
builders/electritains have installed.

This second requirement places significant restraints on the
: circuit as a whole, and drastically limits the total power
supply
: capability. Hence the proliferation of inflexible[1] low
current rated
: circuits you get in places like the US.
:
: [1] Think about a kitchen / utility room with tumble drier,
dish washer,
: and washing machine. That could represent 8kW of load -
although it
: would be diverse - the chances of all three being in use at one
time is
: relatively small, and the presence of thermostatic controls on
the
: heaters will mitigate further. These could safely be power on
one 32A
: ring circuit, but would probably require three 16A or 20A
radials to do
: the same job.
:

Indeed, or perhaps even a sub-main feeding a sub-board. Also,
remember if these appliances/utility room is feed via it's own
ring circuit this requires two of the two out of the three cable
runs needed for the radials anyway, cost savings will be minimal
and thus I would prefer the redundancy given by radial circuits,
also radial circuits and 15amp unfused plugs would remove the
issue of either BS1363 plugs stuck behind these difficult to move
appliances, plug and sockets being fitted in cupboards, trailing
leads or hard-wired flex outlet plates.

Most owners don't care how many, or indeed the cross section of
such, wires have been installed in a building (even the fitment
of 5amp lighting points in the wall), what they do notice is
price (of new house or re-wiring a old house), so the choice of
ring vs. radial circuit comes down to cost at the end of the day,
not really the technical pros and cons of each.
--
Regards, Jerry.

Have you ever been here?

On 3 Sep, 06:56, The Wanderer wrote:
On Thu, 2 Sep 2010 21:56:14 +0100, Jerry wrote:
"The Wanderer" wrote in message
. ..
: On Thu, 02 Sep 2010 14:04:40 +0100, John Rumm wrote:
:
:
: No offence Jerry, but this is a load of ill thought out
twaddle.
:
: snipped excellent reply
:
: What an elegantly crafted reply!
:

Another unthinking parrot, "the regs say such and such, so that
is that then"...

Whatever you say, Jerry.

I'm minded of the proud mum watching her army son marching with all his
fellow squaddies. 'Ooh look! My son's the only one in step......'

--
The Wanderer

Inertia keeps me going!- Hide quoted text -

- Show quoted text -

We're talking about a Yank here. They don't even get a proper
education.

On Sep 2, 10:33*am, "Jerry" wrote:
"Bob Eager" wrote in message

...
: On Thu, 02 Sep 2010 09:14:39 +0100, Jerry wrote:
:
: I take it that you have never come across the bolt being used
as
: a 'fusible' link within the a Bullshi... sorry BS1363 plug
that is
: feeding a device that draws 3amp via a similar rated length
of flex.
:
: And this never happens with other fuses? Of course it does.
Anyway, it's
: quite hard to use *abol;t with many modern moulded plugs.

********, it only need metal the same dia of the BS fuse,

How many people do you know who would go to the bother of finding a
bolt of the correct diameter and cutting it to length just to avoid
fitting a fuse? An incorrectly rated fuse is a far more likely
scenario.

MBQ

On Sep 2, 8:48*pm, "Jerry" wrote:
"John Rumm" wrote in message

...
: On 02/09/2010 10:33, Jerry wrote:
:
: Only if you are being a pedantic fool and taking the meaning
of
: the word "House" to me a multi floor dwelling rather than the
: more usual generic meaning of the word as a place were people
: live. Anyway, even if there was multiple ring circuits one
faulty
: device will still take out all devices being powered from
that
: circuit rather than just the one or two that would be on a
radial
: circuit.
:
: Although I suspect that Jerry has not realised it, his beef
seems to be
: with fused plugs, since he has actually highlighted nothing of
relevance
: to circuit topology.

Yes, and I have said that both radial and ring circuits have both
advantages and disadvantages.

*Plug fuses can be abused (as can rewireable fuses
: in consumer units), however in reality this much less of a
problem that
: might be imagined.

But we are talking about (theoretical) risks, allowing the
ignorant to defeat final protection with not much more than a
kitchen or pen knife and thus compete for a "Darwin Award" has a
very much higher risk factor than many of the risk that the regs
are obsessed with now!

Fine.

The regs, if followed, will protect everyone from bad installation.
They might not, and should not attempt to IMHO, protect you from
yourself.

MBQ

On Sep 2, 8:48*pm, "Jerry" wrote:


Not so sure, whilst many appliances are sold all over the world,
since the UK law has required the pre-fitment of BS1363 plugs
complete with the correctly rated BS fuse many appliances now
come with power leads not only with moulded on plugs but the lead
rated to the fitted fuse IYSWIM.

I can think of numerous devices that come with various gizmos to adapt
them to a number of plug styles, rather than pre-fitted or moulded-on
BS plugs. Sometimes the BS style pins slide on and lock into place,
but are not pre-fitted. Others have a clamshell style adapter that
fits around a euro style two pin plug.

All carry CE marks and were purchased in the UK. Unless there's a
massive conspiracy among manufacturers and/or importers, then I thinnk
the UK law must have been relaxed or re-worded somewhat.

MBQ

On Sep 2, 9:09*pm, "Jerry" wrote:
"harry" wrote in message

...

: You are in cloud cuckoo land.

Well, perhaps, but then I live in the real world and not that
perfect world that you seem to inhabit, were if something is
meant to happen it always will, like all company supply neutral
fuses having been removed by the mid 1980s or that the BS1364
plug will always have the correct fuse installed, or indeed any
fuse...

snip
: The [UK] system is cheap to install and extend,
: safer than American and European systems, more
: flexible and efficient.

The only true statement in the above is the words "cheap to
install". The problem with North American system is more to do
with quality (of the components used) rather than the design of
the circuits, same is true of European systems added to issues of
workmanship [1]. How is someone in the UK being able to protect
their 3amp table lamp via a bolt (or indeed a 13amp fuse) in the
BS1363 plug and the 20 to 30A CB at the D-board any more safe
than someone in either the US or EU plugging the same 3amp table
lamp into a wall socket protected at ~15amp CB at the D-board?

http://en.wikipedia.org/wiki/Straw_man

No one in this thread is claiming that abusing the system is any
safer, only that the incidence of such behaviour leading to a
"problem" is so small as to be an acceptable risk.

MBQ

On Sep 2, 9:09*pm, "Jerry" wrote:

: The [UK] system is cheap to install and extend,
: safer than American and European systems, more
: flexible and efficient.

The only true statement in the above is the words "cheap to
install". The problem with North American system is more to do
with quality (of the components used) rather than the design of
the circuits, same is true of European systems added to issues of
workmanship [1]. How is someone in the UK being able to protect
their 3amp table lamp via a bolt (or indeed a 13amp fuse) in the
BS1363 plug and the 20 to 30A CB at the D-board any more safe
than someone in either the US or EU plugging the same 3amp table
lamp into a wall socket protected at ~15amp CB at the D-board?

[1] and shoddy workmanship is also a problem in the UK also
--

I've worked on countless North American installations and equally on
countless UK installations.

My conclusions?

1. North American installations do indeed tend to use components --
especially wall receptacles and plugs -- of unbelievable crudeness and
totally-deplorable quality. Quality components are available, but
absent from almost all domestic installations. The electricity supply
isn't up to the job -- sadly, 110v and the consequent high current
draw means that there are rarely enough circuits and tripping the
breaker is an everyday occurrence in a very large proportion of
installations. 220v is needed anyway, for the stove and dryer, not to
mention air conditioning units. Surprisingly, switches are
remarkably long-lived and some good ones are readily available. And
the ES lamp socket is inherently a better socket design in physical
terms than a BC one.

2. I'd much sooner live with UK installations. Ring mains and BS1363
are both IMHO very much superior to other practices. The horrendous
weakness of UK installations is to be found in BC22 lampholders which
in domestic use are almost invariably made of cheap and nasty plastic
which disintegrates very rapidly. BC lampholders CAN be properly
made -- and indeed I replace failed plastic ones with brass+porcelain
ones which are just fine, but really, the design is flawed.

On 02/09/2010 20:53, Adrian C wrote:


OK, 9am tomorrow I'm going to warm up their 'general enquiry' phone
wires a bit.


Job done :-) Thanks all for the comments.

After 10 minutes of SWMBO blowing her fuse on the phone, 3 electrical
company vehicles turned up. One of these was a transit towing an
excavator on a trailer, another was a van and the other a range rover.
Disappointed to see no helicopter.

Anyway four nice chaps looked at the nicely laid pavement outside our
house, decided that they weren't going to dig all that up to temporarily
isolate us, and instead proceeded to the nearest electrical manhole
cover to work out which phase to isolate by pulling things.

So unfortunately a number of our neighbours (some out of 50 houses in
the street) were without electricity for a good hour, and when power was
returned their burglar alarms tripped, the noise set the dogs off, and
our mad nutty next door neighbour (sadly on the same phase, but
different planet) stuck even more pins in his voodoo doll replica of me.

The replacement work involved melting the semicircular 'boat' of
bitumen, cleaning up the cables and installing a single 60A fuse in the
live conductor, linking out the neutral and fitting a new earth to the
incoming cable shield.

http://i912.photobucket.com/albums/ac327/turnstyler/newunderthestairs.jpg

This is now me wiring mess, which one day I'll get around to sorting
with a new consumer unit. I asked whether they could fit me an isolating
switch past the meter but was told they stopped doing that favour for
customers 5 years ago.

Another neighbour popped in and asked whether his similar 1930's fuses
could be changed and was told it's done on an emergency case by case
basis - 'just phone up the helpline and tell 'em you smell burning, and
it will be done...'. Ah, it was _that_ easy then :-(

For interest, these are the removed fuses.
http://i912.photobucket.com/albums/ac327/turnstyler/IMG_3463.jpg

--
Adrian C

On 3 Sep, 16:40, Adrian C wrote:
On 02/09/2010 20:53, Adrian C wrote:



OK, 9am tomorrow I'm going to warm up their 'general enquiry' phone
wires a bit.

Job done :-) Thanks all for the comments.

After 10 minutes of SWMBO blowing her fuse on the phone, 3 electrical
company vehicles turned up. One of these was a transit towing an
excavator on a trailer, another was a van and the other a range rover.
Disappointed to see no helicopter.

Anyway four nice chaps looked at the nicely laid pavement outside our
house, decided that they weren't going to dig all that up to temporarily
isolate us, and instead proceeded to the nearest electrical manhole
cover to work out which phase to isolate by pulling things.

So unfortunately a number of our neighbours (some out of 50 houses in
the street) were without electricity for a good hour, and when power was
returned their burglar alarms tripped, the noise set the dogs off, and
our mad nutty next door neighbour (sadly on the same phase, but
different planet) stuck even more pins in his voodoo doll replica of me.

The replacement work involved melting the semicircular 'boat' of
bitumen, cleaning up the cables and installing a single 60A fuse in the
live conductor, linking out the neutral and fitting a new earth to the
incoming cable shield.

http://i912.photobucket.com/albums/ac327/turnstyler/newunderthestairs...

This is now me wiring mess, which one day I'll get around to sorting
with a new consumer unit. I asked whether they could fit me an isolating
switch past the meter but was told they stopped doing that favour for
customers 5 years ago.

Another neighbour popped in and asked whether his similar 1930's fuses
could be changed and was told it's done on an emergency case by case
basis - 'just phone up the helpline and tell 'em you smell burning, and
it will be done...'. Ah, it was _that_ easy then :-(

For interest, these are the removed fuses.
http://i912.photobucket.com/albums/ac327/turnstyler/IMG_3463.jpg

--
Adrian C

No lead seal on the suppliers fuse as yet - so you have an isolator
for the time being! (but only pull that fuse out with the CU's
isolated)

Glad you got it sorted mate.

On Fri, 03 Sep 2010 16:40:02 +0100, Adrian C wrote:

On 02/09/2010 20:53, Adrian C wrote:


OK, 9am tomorrow I'm going to warm up their 'general enquiry' phone
wires a bit.


Job done :-) Thanks all for the comments.


There, just got to know the right direction to go! :-)



--
The Wanderer

Whenever I look for something, it's always in the last place I look.

Try http://ukpanels.com/forum1/index.php

Adrian C wrote:

http://i912.photobucket.com/albums/ac327/turnstyler/newunderthestairs.jpg

I asked whether they could fit me an isolating
switch past the meter but was told they stopped doing that favour for
customers 5 years ago.

You(?) managed to insert the Henley blocks between meter and CUs, so why
not precede those with your own isolator?

Andy Burns wrote:
Adrian C wrote:

http://i912.photobucket.com/albums/ac327/turnstyler/newunderthestairs.jpg

I asked whether they could fit me an isolating
switch past the meter but was told they stopped doing that favour for
customers 5 years ago.

You(?) managed to insert the Henley blocks between meter and CUs, so
why not precede those with your own isolator?

That is not the same as getting an isolator for free!

--
Adam

On Sep 4, 12:21*pm, "ARWadsworth"
wrote:
Andy Burns wrote:
Adrian C wrote:

http://i912.photobucket.com/albums/ac327/turnstyler/newunderthestairs....

I asked whether they could fit me an isolating
switch past the meter but was told they stopped doing that favour for
customers 5 years ago.

You(?) managed to insert the Henley blocks between meter and CUs, so
why not precede those with your own isolator?

That is not the same as getting an isolator for free!

--
Adam

No, but at least you get it in there without any hassle and before
some meter reader reports the company fuse as being unsealed.

Of course, meter readers are becoming a thing of the past now. Had a
guy from British Gas replacing one electrical meter this week with a
meter which they can dial up on the mobile phone network in order to
read it. Neat.

--
John MacLeod

ARWadsworth wrote:

Andy wrote:

You(?) managed to insert the Henley blocks between meter and CUs, so
why not precede those with your own isolator?

That is not the same as getting an isolator for free!

I only paid about a fiver for a Wylex REC2S on thiefbay.