On 07 Jul 2005 20:48:55 GMT,it is alleged that
(Andrew Gabriel) spake thusly in uk.d-i-y:

45 amps will be generating some 10kW at the scene of the fault.
It would be pretty impossible to even deliberately engineer such
a fault which lasted more than a few seconds, without it either
shorting completely or blowing itself out into an open circuit.
The generation of 10kW will change the nature of a fault site
very quickly.

There just aren't credible scenarios where large currents flow
for an extended period in the earth conductor.

Fair point :-)

On a fully loaded US system, the neutral current is zero.
Same is true of a fully loaded 3-phase system in UK, which
is why 4-wire 3-phase circuits do sometimes have reduced
size neutrals (need to watch out for 3rd-harmonic components
though, which do add in the neutral rather than cancel out).

Yep, many people in the US are now being caught out by needing larger
size neutrals than phase conductors, especially in IT rich
environments such as office space etc, where the PC and IT equipment
PSUs generate nasty harmonics and cause local overheating of the
neutrals, not good.

--
I have left orders to be awakened at any time in case of national emergency,
even if I'm in a cabinet meeting.
- Ronald Reagan

In message ,
(Andrew Gabriel) wrote:

In article ,
(Brian {Hamilton Kelly}) writes:
On 18 Jun 2005 22:46:09 GMT, (Andrew
Gabriel) wrote:
Transformer size is really only an issue on planes and boats, which
often do use 400Hz.

A *lot* of military hardware, neither afloat nor airborne, uses 400Hz for
power distribution, not just to cut down on the mass of transformers, but
also on their bulk.

Well, perhaps I should have broadened it to say portable/transportable.

I also got some private feedback from someone who used to be in the supply
industry who said transformer size _is_ important to them -- they want
them big and heavy, so they can't be stolen ;-)

Didn't stop someone stealing a 75MVA (? might be a factor out there, it
was a few years ago) transfromer from the ex-steelworks at
Templeborough. When British Steel handed the building over to the group
which turned it into the Magna Science Adventure Centre (I worked there
for a while) they left the last arc furnace transformer parked in the
lot while they found somewhere to put it.

No-one knows what happened to it, and it must have involved a large
crane and a low-loader, but when they came to claim it just before the
centre opened it was no longer there. Magna ended up paying a lot of
money to BS for having "lost" their transformer.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... My other neighbour is quiet.

Martin Angove wrote:
In message ,
(Andrew Gabriel) wrote:

I also got some private feedback from someone who used to be in the supply
industry who said transformer size _is_ important to them -- they want
them big and heavy, so they can't be stolen ;-)


Didn't stop someone stealing a 75MVA (? might be a factor out there, it
was a few years ago) transfromer from the ex-steelworks at
Templeborough. When British Steel handed the building over to the group
which turned it into the Magna Science Adventure Centre (I worked there
for a while) they left the last arc furnace transformer parked in the
lot while they found somewhere to put it.

No-one knows what happened to it, and it must have involved a large
crane and a low-loader, but when they came to claim it just before the
centre opened it was no longer there. Magna ended up paying a lot of
money to BS for having "lost" their transformer.


bit hard to resell that one...

NT

"Jim Michaels" wrote in message
...
On 07 Jul 2005 07:50:51 GMT, andrew@a17 (Andrew Gabriel) wrote:

In article ,
Jim Michaels writes:
On 04 Jul 2005 18:17:37 GMT, (Andrew
Gabriel) wrote:

In article
.com,
writes:

Youre not understanding safety margin. Size of cable has
nothing to do
with it, once the cables big enough not to overload. Ours are
big
enough and much more. Yours are even bigger, but for what? Its
just
poor engineering.

Because voltage drop is a serious issue for 120V supplies.
It's not for 240V supplies.

No, Our supplies are also 240V

Nope -- you require regulation mostly at the 120V level.

This is getting tedious.

We have a 240Volt supply to our homes!

It is the Edison 3 wire balanced system, where there are two power
conductors 180 degrees out of phase (240V between legs and 120V from
each leg to neutral/earth) and a neutral conductor at nominally
earth
potential.

Therefore for a home which normally has a reasonably balanced load
(see diversity) the voltage drop from the CU back to the generating
plant will be the same as a British/euro 240V single phase delivery
system.

As far as small branch circuits go, many are multi wire circuits
with
two hot legs and a neutral that only carries the imbalance between
the
loads. (see diversity) When balanced the voltage drop is EXACTLY the
same as your 240V to earth supply.

ALL large loads operate at 240V and therefore have a voltage drop
and
current the same as any other 240V system.

Voltage drop is NOT a significant issue in US residential wiring.

You seem to want there to be problems where none exist, and to
magnify
small problems into disasters.



Remove SPAMX from email address


Lots of disasters in the early days. Very interesting article at:

http://www.swehs.co.uk/docs/news25su.html

All about Sebastian de Ferranti's early championing of HV AC
distribution. Descriptions of the Ferranti / Siemans zig/zag 10,000v
alternator. In the mid 1970's there was an example of this machine in
the foyer to Ferranti's 'Wireworks Factory' at Moston in Manchester
where I spent several months commissioning computers.

AWEM

On Fri, 08 Jul 2005 15:11:25 -0500, Jim Michaels
wrote:



Voltage drop is NOT a significant issue in US residential wiring.



Really??? Then perhaps you can explain why a colleague can't use a
hairdryer properly when plugged into a socket in his dressing room
because the nominal 120v at the incoming supply has dropped to about
90v at the socket.



--

..andy

To email, substitute .nospam with .gl

The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

In article ,
Jim Michaels wrote:
Besides an electric kettle what else would draw more than 1.6kW in a
normal household?

Any number of kitchen devices. Toaster, grill, fryer, bread maker, clothes
iron. Some power tools. Portable heater. All of which you may want to use
in more than one position and need to be unplugged for cleaning - or
simply to be put away.

It makes no sense to me to have two different power circuits in a house.

--
*Caution: I drive like you do.

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

In article ,
Jim Michaels wrote:
http://houses.dsu.org.uk/info?i=6

Indicates 2500 killed & injured per year in UK

It's a pressure group. And probably manipulating the figures - as they do.

http://www.expertlaw.com/library/fires/home_fires.html

Indicates 1610 killed & injured per year in US

These numbers seem to include all ALL electrical fires

It says 110 fires *per day* That makes 40150. Perhaps your different legal
and health care system prevents minor injuries being reported?

--
*Starfishes have no brains *

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

In article ,
"Dave Plowman (News)" writes:
In article ,
Jim Michaels wrote:
If anyone here wanted one they could
install an outlet and buy a British kettle.

I didn't think your regs allow 240V outlets for portable appliances?

Besides an electric kettle what else would draw more than 1.6kW in a
normal household?

Any number of kitchen devices. Toaster, grill, fryer, bread maker, clothes
iron. Some power tools. Portable heater. All of which you may want to use
in more than one position and need to be unplugged for cleaning - or
simply to be put away.

It makes no sense to me to have two different power circuits in a house.

This question always amuses me -- it never comes from an American
who is familiar with appliances in use around the rest of the world
though. Of course you don't have portable appliances over 1.6kW, as
no one can take them home and plug them in. That means there are
ranges of products in use around the rest of the world which simply
aren't shipped to the US. Many microwaves here are over 2kW. Out of
curiosity I went looking for my microwave model when I was in the
US to see how the price compared, but couldn't find it -- only the
bottom of the range ones were there. Then I suddenly realised why.

Another example is vacuum cleaners. On the face of it, you do have
identical models, but they are all lower power. This I couldn't
initially understand as ours are typically 1.5kW which can just be
squeezed out of a US outlet, so I asked someone in that industry.
The problem there is cable verses voltage drop -- a cable of the
length required on a vacuum cleaner would be too thick to handle
easily or coil up for storage, so they typically limit their US
models to something nearer 10A so they can use a managable mains
cord without excessive voltage drop or over-heating if still
partially coiled up.

I guess you don't miss what you haven't had, but don't fall into
the trap of thinking the rest of the world is also limited to
1.6kW portable appliances -- that's certainly not the case.

--
Andrew Gabriel

In message ,
"Dave Plowman (News)" wrote:

In article ,
Jim Michaels wrote:
http://houses.dsu.org.uk/info?i=6

Indicates 2500 killed & injured per year in UK

It's a pressure group. And probably manipulating the figures - as they do.

http://www.odpm.gov.uk/stellent/grou...029959-02.hcsp

"...on average there are at least 24 deaths and 587 reported non-fatal
injuries per year due to electrical fires reported in dwellings in
England & Wales. Between 25% and 30% of the casualties are directly
associated with the fixed installation."

In other words, 70% to 75% of electrical injures are due to appliances,
which relates to a mere 7 deaths and 176 non-fatal injuries attributable
to the fixed installation.

And I've seen posts here disputing even those figures.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... If we left the bones out it wouldn't be crunchy.

Jim Michaels wrote:

Some where in this thread!

UK Ten 100watt lamps at 240V equal 4.166 amps on circuit rated at 6
amps with 1mm wire.

US Five 100 watt lamps at 120V equals 4.166 amps on 15amp rated
circuit with 14gauge (2.08mm) wire.

In this example the US system has a massively greater safety margin.

This is comparing apples with plums!

Try 10 x 100w @240V and 10 x 100w @120V Currents are 4.2A and 8.4A.
I2R Losses are in the ratio 17.6:35 , allowing for the greater cable
areas at 120V. The US has to have thicker cables to attempt to
compensate for the higher currents, but from this example the
temperature rise in the US cables for the same load will be more than
double as the tc of copper is positive! Particularly true in the South
with their much higher daily temperatures. I believe that UL cables are
using higher temperature resistant coverings than the UK, perhaps
someone knows this?

Incidentally, my pocket reference for US wiring specifies 12g 3.3mm2 as
being the minimum required size for US homes today(NEC code) and the
maximum voltage drop as being 2%. For the example above a likely wire
gauge would be 9g! 6.6mm2! With only radial wiring, the cost penalty is
phenomenal!

Just a few comments.

Regards
Capitol

On Tue, 12 Jul 2005 22:35:44 +0100,it is alleged that Capitol
spake thusly in uk.d-i-y:

[snip]

I believe that UL cables are
using higher temperature resistant coverings than the UK, perhaps
someone knows this?

Usually 90 degrees C (yes, it's specified in celsius).
But derating and so forth means you have some tables in the NEC that
require you to use 60 or 75 C temperature ratings.

Older cable was I think 60 degrees C.

Incidentally, my pocket reference for US wiring specifies 12g 3.3mm2 as
being the minimum required size for US homes today(NEC code)

That depends if the code is adopted in your particular area, most
areas don't enforce the entire code AIUI.

Areas can also specify requirements over and above the NEC, such as
Chicago requiring EVERYTHING in conduit, everywhere.

and the
maximum voltage drop as being 2%. For the example above a likely wire
gauge would be 9g! 6.6mm2! With only radial wiring, the cost penalty is
phenomenal!

You can't generally get odd numbered wire guages and even 10 gauge
will *not* connect to light switches.
Having 10x100w lamps on one circuit would be unheard of in a home,
remember the circuits are shared power/lighting, with generally an
average of 1-2 rooms/circuit for low loads, and living areas 1 circuit
per room minimum.

I agree, the US electrical system uses a _lot_ more copper than the UK
one, however, cable is cheap, and recyclable.

Rewiring a US house is almost exactly comparable with a UK one in
cost, I rewired a 2 bedroom house for my ex in Ohio, (no permits
required provided we didn't replace the main panel, according to the
city inspector). It cost about $400 in cable, (I used all 12G) another
$150 or so in switches/outlets, $200 in light fixtures (fans raised
the cost there), and another hundred for odd sundries, cable clips,
wirenuts and a couple of boxes.
(we didn't replace the old electrical boxes in most cases as they were
reusable)

That's about GBP 600 all told, not bad for a total rewire. We spent a
weekend stripping down the old cable and taking it to the scrap dealer
for cigarette money g.

--
In those days spirits were brave, the stakes were high, men were REAL men,
women were REAL women, and small furry creatures from Alpha Centauri were
REAL small furry creatures from Alpha Centauri.
- The Hitchhiker's Guide to the Galaxy

In article ,
Jim Michaels wrote:
I didn't think your regs allow 240V outlets for portable appliances?

Sure, In residential use the intended devise must draw over 1440W, in
other situations there are no restrictions.
We can even put them in bathrooms!

But then will require two sizes of sockets? We used to have that 50 years
ago. ;-) Now the only required is a different one for things like table
lights plugged into a lighting dimmer circuit where you'd want to avoid
damaging the dimmer by plugging in a Hoover, etc.

--
*Everyone has a photographic memory. Some just don't have film.

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

Two 1.5kW electric fires produce the same heat as one 3kW and are more
versatile.

Well, I've got several 3kW ones (and a couple of 2kW) and they're more
versatile than several 1.5kW ones. 3kW ones cost the same price as smaller
ones.

The main problem is with large kitchen appliances, which we can just plug in
where convenient without having to have special points put in, or
alternatively have to put up with inferior designs without built in heaters.

Christian.

"Jim Michaels" wrote in message
...

Two 1.5kW electric fires produce the same heat as one 3kW and are more
versatile.


And cost twice as much..

Admittedly grilling and frying are not usually done on portable units
in the US. but yours seem to max out at only 1900watts.

US Portable power tools are up to 1,800watt. A large router is an
example.

My 3HP semi-portable contractors saw can be plugged in anywhere here -
garage, shed, house. No need to run special 240V or 3 phase lines for it.

What portable tools do you have that are more than this?

Are you hiding the two man SDS Plus Plus Plus drills?


lol - I want one!!


It makes no sense to me to have two different power circuits in a house.

This question always amuses me -- it never comes from an American
who is familiar with appliances in use around the rest of the world
though. Of course you don't have portable appliances over 1.6kW, as
no one can take them home and plug them in. That means there are
ranges of products in use around the rest of the world which simply
aren't shipped to the US. Many microwaves here are over 2kW.

Google does not seem to find any UK microwaves over 1,000 watt output.
US full size units are also 1,000 watt output.


Often we have combi microwaves with a 1200w microwave *and* a 1300w heating
element for grilling/browning which get used simultaneously. 2500w. Try the
LG MC766YS.

Out of
curiosity I went looking for my microwave model when I was in the
US to see how the price compared, but couldn't find it -- only the
bottom of the range ones were there. Then I suddenly realised why.

You are shopping in the wrong stores.

Another example is vacuum cleaners. On the face of it, you do have
identical models, but they are all lower power. This I couldn't
initially understand as ours are typically 1.5kW which can just be
squeezed out of a US outlet, so I asked someone in that industry.

We have 1400 and 1500 watt units available from the major
manufacturers


1400w is a small one here. 2000w is easily available even in a small
cylinder vacuum. I guess thats partly why built in vacuums are more popular
over there than here.

In message ,
Jim Michaels wrote:


Google does not seem to find any UK microwaves over 1,000 watt output.
US full size units are also 1,000 watt output.


An interesting statement that. Of course you are aware that 1000W
microwave output usually translates into about 2000W absorbed energy, in
which case, presumably the "full size" US units you refer to have to be
specially catered for rather than just plugged into a standard circuit?

The very smallest microwave you can generally get in this country is
650W output which probably makes for 1300W energy consumption, which is
interestingly close to the nominal 1500W capacity of a standard 120V US
circuit.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... Don't believe in astrology. We Scorpios aren't taken in by such things.

On Thu, 14 Jul 2005 17:38:35 +0100,it is alleged that Martin Angove
spake thusly in uk.d-i-y:


The very smallest microwave you can generally get in this country is
650W output which probably makes for 1300W energy consumption, which is
interestingly close to the nominal 1500W capacity of a standard 120V US
circuit.

1800 watts is the actual capacity, fwiw, most microwaves that I am
aware of in the US (IE those I came across while there) were around
750-800w rated output, with a 950 in one particular location (lobby of
the motel I worked in, it had a 20A plug though).

Interestingly, in most newer houses, according to code, the kitchen
*should* have separate 20A small appliance circuits for the dishwasher
and microwave[1], being 2 of the highest loading appliances. (US
dishwashers, unlike washing machines, are similar to their UK
brethren, and use a heating element for the drying cycle and to heat
the water).

[1] I don't think the code requires 20A outlets though, a duplex 15A
is allowed on a 20A circuit, most installers probably do this for
cheapness.

--
Life is like a hot bath. It feels good while you're in it, but the
longer you stay in, the more wrinkled you get.
- Robbert Oustin

In article ,
Jim Michaels writes:
Besides an electric kettle what else would draw more than 1.6kW in a
normal household?

Any number of kitchen devices. Toaster, grill, fryer, bread maker, clothes
iron. Some power tools. Portable heater. All of which you may want to use
in more than one position and need to be unplugged for cleaning - or
simply to be put away.

Google seems to indicate that your toasters and bread makers are the
same wattage as ours.
Your steam irons appear to range from the same to about 20% higher
wattage. How does this effect their use?, do you iron asbestos
clothes?

Probably faster heatup and more steam production.

Two 1.5kW electric fires produce the same heat as one 3kW and are more
versatile.

Electric heaters here (and I think all 230V countries) are either 2kW
or 3kW. Usually they can be switched down to 1kW if that's all you want.
Two 1.5kW electric fires would be a pain to store, and twice as expensive
to purchase. Two 1.5kW electric fires would overload a room circuit in
the US.

Admittedly grilling and frying are not usually done on portable units
in the US. but yours seem to max out at only 1900watts.

I had an old Rowenta grill when I was a student which I think my
parents now have, and that's 2kW.

US Portable power tools are up to 1,800watt. A large router is an
example.

What portable tools do you have that are more than this?

One that I was using a few days ago -- wall paper stripper at 2.4kW.
Another is hot air guns, a friend's one I've borrowed is 2.4kW.
Pressure washers are available over 2kW.

Google does not seem to find any UK microwaves over 1,000 watt output.
US full size units are also 1,000 watt output.

Look at the input power, and look for combination ovens which have
long since taken over from microwaves here. Mine, which is a bog
standard Sharp one, is 2.65kW.

--
Andrew Gabriel

Jim Michaels wrote:
On 12 Jul 2005 09:04:23 GMT, (Andrew
Gabriel) wrote:

Google seems to indicate that your toasters and bread makers are the
same wattage as ours.

Most I've have has been 3kW, 240v 13A. One ancient one was 240v 15A,
from the round pin days.


Your steam irons appear to range from the same to about 20% higher
wattage. How does this effect their use?, do you iron asbestos
clothes?

heatup time. 3kW electric kettles are common here.


Two 1.5kW electric fires produce the same heat as one 3kW and are more
versatile.

no


Admittedly grilling and frying are not usually done on portable units
in the US. but yours seem to max out at only 1900watts.

US Portable power tools are up to 1,800watt. A large router is an
example.

What portable tools do you have that are more than this?

There are some, especially older ex-commercial equipment, but as you
say the majority are under 2kW


Are you hiding the two man SDS Plus Plus Plus drills?

Lol!

Even a 29kg road breaker is only 1.9kW. Welders are liable to be 13A or
more. Screwfix chopsaw 32129 is 2.4kW, 63319 is 2.2kW. 130A welders eg
63152, 17764, 12219 run on a 13A plug.


Google does not seem to find any UK microwaves over 1,000 watt output.
US full size units are also 1,000 watt output.

input power is what counts. Output is only around 50% of input, if
rated honestly. Theyre no longer rated honestly of course, since the
late 90s high optimism IEE ratings took over.


Another example is vacuum cleaners. On the face of it, you do have
identical models, but they are all lower power.

IIUC american portable power appliances are rated very differently,
often being rated on surge or startup power to give most optimistic
figures. Makes it very hard to compare.


We have 1400 and 1500 watt units available from the major
manufacturers

hard to know what those ratings really mean in US.


NT

In message ,
Jim Michaels wrote:

Google does not seem to find any UK microwaves over 1,000 watt output.
US full size units are also 1,000 watt output.

Our nukes range from 450w to 1kW output, with inputs of 900w to 2kW for
vanilla nukes. Combi ovens are higher power, since almost all run the
magnetron and 1kW element together, typically around 2.6 kW.

Note the newer power rating system confuses things somewhat, and
obviously the lower power ovens dont have their output power marked on
them.

A quick scan of screwfix reveals several 2-3kW tools, eg welders, wall
chasers, compressors, 14A nailer guns, heat guns, steamers / wallpaper
strippers, angle grinders, routers, universal woodworking machine, and
many more in the 1.5-1.8 kW range as well. Portable ovens are mostly
3kW, except for the junk ones.


NT

On Thu, 14 Jul 2005 17:38:35 +0100, Martin Angove
wrote:

In message ,
Jim Michaels wrote:


Google does not seem to find any UK microwaves over 1,000 watt output.
US full size units are also 1,000 watt output.


An interesting statement that. Of course you are aware that 1000W
microwave output usually translates into about 2000W absorbed energy, in
which case, presumably the "full size" US units you refer to have to be
specially catered for rather than just plugged into a standard circuit?

Sounds a bit unlikely, a 1kW microwave at 50% efficiency would also
generate the same heat as a 1kW fan heater! That would require a lot
more ventilation than they appear to have.

My combi oven is about 66% efficient, the Panasonic ones using an
inverter are about 80% efficient:

http://www2.panasonic.com/webapp/wcs/stores/servlet/vModelDetail?storeId=15001&catalogId=13401&itemId= 93565&cacheProgram=11002&cachePartner=700000000000 0005702&surfModel=NN-S505WF&catGroupId=25069&surfCategory=Standard%20Co unter%20Top&displayTab=O


The very smallest microwave you can generally get in this country is
650W output which probably makes for 1300W energy consumption, which is
interestingly close to the nominal 1500W capacity of a standard 120V US
circuit.


The above 1200W oven can run off a single 15A supply in the US, not
bad for about 50 quid!

cheers,
Pete.

In article ,
Pete C writes:
On Thu, 14 Jul 2005 17:38:35 +0100, Martin Angove
wrote:
An interesting statement that. Of course you are aware that 1000W
microwave output usually translates into about 2000W absorbed energy, in
which case, presumably the "full size" US units you refer to have to be
specially catered for rather than just plugged into a standard circuit?

Sounds a bit unlikely, a 1kW microwave at 50% efficiency would also
generate the same heat as a 1kW fan heater! That would require a lot
more ventilation than they appear to have.

Original magetrons were only 50% efficient.
Over the last few years, I think this has improved,
but there was also a change in the way microwave
output power was measured, which makes them look
better than they used to look, for no actual change.

The waste heat comes from the magnetron, and in
simple (non-combination) ovens, it was often blown
through the oven compartment to help with the food
heating.

--
Andrew Gabriel

In message ,
(Andrew Gabriel) wrote:

In article ,
Pete C writes:
On Thu, 14 Jul 2005 17:38:35 +0100, Martin Angove
wrote:
An interesting statement that. Of course you are aware that 1000W
microwave output usually translates into about 2000W absorbed energy, in
which case, presumably the "full size" US units you refer to have to be
specially catered for rather than just plugged into a standard circuit?

Sounds a bit unlikely, a 1kW microwave at 50% efficiency would also
generate the same heat as a 1kW fan heater! That would require a lot
more ventilation than they appear to have.

Original magetrons were only 50% efficient.
Over the last few years, I think this has improved,
but there was also a change in the way microwave
output power was measured, which makes them look
better than they used to look, for no actual change.

The waste heat comes from the magnetron, and in
simple (non-combination) ovens, it was often blown
through the oven compartment to help with the food
heating.

I've met quite a few nukes in my time, and I have to say that when you
compare the ratings plate (which for legal reasons has to be pretty
accurate about the absorbed power) with the declared power output, the
ratio is usually quite close to 2:1. I'd love to meet one of these
supposedly 80% efficient devices though.

Do they have ratings plates in the US?

Whether or not a 50% efficiency is going to be noticeable really depends
on the type of use the oven gets. 60 seconds spent heating a cup of
cocoa, even with 1kW dissipated as "waste" heat isn't going to be very
obvious. Last time I had our (850W output) oven on for 5 minutes (doing
a couple of bowls of supermarket-takeaway rice) it did get quite warm.
There's definitely a fan in there somewhere...

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... If speed scares you, try Micro$oft Windows.

On Fri, 15 Jul 2005 00:42:14 +0100, Martin Angove
wrote:


I've met quite a few nukes in my time, and I have to say that when you
compare the ratings plate (which for legal reasons has to be pretty
accurate about the absorbed power) with the declared power output, the
ratio is usually quite close to 2:1.

Mine's 1450W in for 900W out, making it 1.6:1

I'd love to meet one of these
supposedly 80% efficient devices though.

Here it is, got snipped out :
http://www2.panasonic.com/webapp/wcs/stores/servlet/vModelDetail?storeId=15001&catalogId=13401&itemId= 93565&cacheProgram=11002&cachePartner=700000000000 0005702&surfModel=NN-S505WF&catGroupId=25069&surfCategory=Standard%20Co unter%20Top&displayTab=S

Whether or not a 50% efficiency is going to be noticeable really depends
on the type of use the oven gets. 60 seconds spent heating a cup of
cocoa, even with 1kW dissipated as "waste" heat isn't going to be very
obvious. Last time I had our (850W output) oven on for 5 minutes (doing
a couple of bowls of supermarket-takeaway rice)

I tend to use mine for custard, which works really well.

it did get quite warm.
There's definitely a fan in there somewhere...

Agreed, they must all have fans.

cheers,
Pete.

Hwyl!

M.

Martin Angove wrote:

Do they have ratings plates in the US?

I'm currently in the US - so I took a look inside the microwave oven.
The plate reads -

Input 120v 60hz 15 or 20 amp 3-wire only
Output 650 watts 2450mhz 11 amp

It's an old unit, the label says it was manufactured in January 1989.

I don't remember the rating of the one we have in Scotland, but it cooks
faster than this one.

Sheila

In article ,
S Viemeister wrote:
Input 120v 60hz 15 or 20 amp 3-wire only

Well, that doesn't tell you its power consumption - only that it's less
than 1800 watts and it needs to be earthed.

Output 650 watts 2450mhz 11 amp

That seems even worse. 650 watts at 120 volts is 5.4 amps.

--
*Am I ambivalent? Well, yes and no.

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

Pete C wrote:

No microwave is 80% efficient. The invertor might be, but the magnetron
isnt, and the oven as a whole isnt. Apart from invertor types, all are
50% efficient, but the newer IEC rating system makes it appear that
output powers and efficiency have gone up: they havent. Think of them
as like PMPO power ratings. The only significant advatnage of the
invertors is reduced weight.

Chaos defrost is just more marketing nonsense, its no better than
regularly cycled power.


NT

On Fri, 15 Jul 2005 07:55:20 -0400, S Viemeister
wrote:

Martin Angove wrote:

Do they have ratings plates in the US?

I'm currently in the US - so I took a look inside the microwave oven.
The plate reads -

Input 120v 60hz 15 or 20 amp 3-wire only
Output 650 watts 2450mhz 11 amp

How odd. Eleven amps output?

:-)
--
Frank Erskine
Sunderland

In article ,
"Dave Plowman (News)" writes:
In article ,
S Viemeister wrote:
Input 120v 60hz 15 or 20 amp 3-wire only

Well, that doesn't tell you its power consumption - only that it's less
than 1800 watts and it needs to be earthed.

Output 650 watts 2450mhz 11 amp

That seems even worse. 650 watts at 120 volts is 5.4 amps.

It's an old unit, the label says it was manufactured in January 1989.

Yes, so efficiency of about 50%, which is typical then.
Power factor of microwave ovens is not quite 1, but it's
near enough that can probably be ignored at this level.

I don't remember the rating of the one we have in Scotland, but it cooks
faster than this one.

Domestic UK ones are typically 600 to 1000W output, so your
UK one could well be more powerful.

--
Andrew Gabriel

"Dave Plowman (News)" wrote:

In article ,
S Viemeister wrote:
Input 120v 60hz 15 or 20 amp 3-wire only

Well, that doesn't tell you its power consumption - only that it's less
than 1800 watts and it needs to be earthed.

Unfortunately, that's the only information on the label.
I would hope that newer units are better, and that their labels more
useful.

Sheila

Frank Erskine wrote:

On Fri, 15 Jul 2005 07:55:20 -0400, S Viemeister
wrote:

Martin Angove wrote:

Do they have ratings plates in the US?

I'm currently in the US - so I took a look inside the microwave oven.
The plate reads -

Input 120v 60hz 15 or 20 amp 3-wire only
Output 650 watts 2450mhz 11 amp

How odd. Eleven amps output?

:-)

That _is_ what it says........

Sheila

On 15 Jul 2005 07:28:19 -0700, wrote:

Pete C wrote:

No microwave is 80% efficient. The invertor might be, but the magnetron
isnt, and the oven as a whole isnt. Apart from invertor types, all are
50% efficient,

Bit of a sweeping statement, that...

but the newer IEC rating system makes it appear that
output powers and efficiency have gone up: they havent. Think of them
as like PMPO power ratings.

Sounds interesting, do you have any web references?

cheers,
Pete.

On Wed, 20 Jul 2005 20:25:51 -0500, Jim Michaels
wrote:

On Thu, 14 Jul 2005 09:50:48 +0100, "Christian McArdle"
wrote:

Two 1.5kW electric fires produce the same heat as one 3kW and are more
versatile.

Well, I've got several 3kW ones (and a couple of 2kW) and they're more
versatile than several 1.5kW ones. 3kW ones cost the same price as smaller
ones.

Versatile
Two 1.5s next to each other is the same as a 3.
One 1.5 in each of two rooms does what no 3 can do.

As far as price we can get 1.5s for $10 to $15 which is so little as
to be a non-issue.


The main problem is with large kitchen appliances, which we can just plug in
where convenient without having to have special points put in, or
alternatively have to put up with inferior designs without built in heaters.

US washing machines use hot water (often heated with gas).

How is saving energy inferior?


The huge volume of water used in top loading machines.



--

..andy

To email, substitute .nospam with .gl

US washing machines use hot water (often heated with gas).

How is saving energy inferior?

US machines use many, many times the quantity of water and detergent and are
an environmental nightmare.

European machines used to have heating elements and a separate hot fill to
start it off. This is no longer done as the machines use so little water
that there is no energy to be saved when you account for the lost hot water
in the pipework every time it fills.

Christian.

Christian McArdle wrote:



US machines use many, many times the quantity of water and detergent
and are an environmental nightmare.

European machines used to have heating elements and a separate hot
fill to start it off. This is no longer done as the machines use so
little water that there is no energy to be saved when you account for
the lost hot water in the pipework every time it fills.

And the result is washing machines which give you back clothes in more
or less the same filthy state as when you put them in! So you have to
wash them 2 or 3 times and the energy efficiency is unbelievably bad.
I'm still regretting not rebuilding my old washing machine when it lost
it's bearings, the local noise level is sometimes near deafening when
she looks at the results of the new machine. Looks to me like the same
effect as replacing an old working boiler with a modern piece of crap
which will not last 5 years without failure! Totally false accounting.
Just like buying a Prius!

Regards
Capitol

On Thu, 21 Jul 2005 20:31:12 +0100, Capitol
wrote:



Christian McArdle wrote:



US machines use many, many times the quantity of water and detergent
and are an environmental nightmare.

European machines used to have heating elements and a separate hot
fill to start it off. This is no longer done as the machines use so
little water that there is no energy to be saved when you account for
the lost hot water in the pipework every time it fills.

And the result is washing machines which give you back clothes in more
or less the same filthy state as when you put them in! So you have to
wash them 2 or 3 times and the energy efficiency is unbelievably bad.
I'm still regretting not rebuilding my old washing machine when it lost
it's bearings, the local noise level is sometimes near deafening when
she looks at the results of the new machine. Looks to me like the same
effect as replacing an old working boiler with a modern piece of crap
which will not last 5 years without failure! Totally false accounting.
Just like buying a Prius!

Hi,

What make and model machine do you have, and what temperature do you
use? Do you know what the wash efficiency rating is?

cheers,
Pete.

In message ,
Jim Michaels wrote:


The standard Kitchen circuit is 20amps at 120V for a 2,400watt
capacity. There is a restriction of 80% for a single item unless it
is a single outlet circuit and often these circuits have receptacles
rated at only 15amps.

The 15amp receptacle is also de rated to 80% if the device is expected
to run over 3 hours (such as a fire). A microwave is permitted to use
the full 1800watts that it's 15amp plug will provide.
Remove SPAMX from email address

So you have a 20 Amp fused (radial) circuit which...

....is only allowed to carry 16A for any single appliance where there is
more than one outlet;

....could have two (or more?) 15A receptacles fitted - unfused;

....could therefore have receptacles fitted which are not rated to the
capacity of the circuit or fused appropriately;

....could have receptacles fitted which although nominally rated at 15A
are only allowed to supply 12A (1440W) continuously (why?, and what on
earth is the difference between over three hours and under three hours?
Over 30 minutes and under 30 minutes I might have understood)

....and how on earth is this policed?

I'm afraid it sounds like a dreadful bodge to me. Compliance with that
kind of code relies hugely on the householder "behaving
themselves". Compare that with our system where every single power
take-off point is either fully rated for the fused capacity of the
circuit (e.g. blue 16A/32A BS4343 plugs) or is separately fused at a
suitable rating (e.g. 13A BS1363 plugs, 13A fused outlets). The onus to
"get it right" is on the installer with these. Once correctly installed
it is difficult for the user to misuse the system dangerously.

Penbleth 8-/

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... Journeys begin with a single step, and a decision to take it.

Pete C wrote:


Hi,

What make and model machine do you have, and what temperature do you
use? Do you know what the wash efficiency rating is?

The machine is a Whirlpool AA1200. Temperature makes virtually no
difference, The problem is IMO with both the wash and the rinse cycles.
The wash efficiency by use is not significantly above zero! It also has
a novel variety of user unfriendly features which we have only found out
by experience. (Seems like about 40 minutes to achieve a rinse and spin
function on hand washed items!) Some we are still learning( the hard way)!

Regards
Capitol

In article ,
Capitol writes:
Pete C wrote:
What make and model machine do you have, and what temperature do you
use? Do you know what the wash efficiency rating is?

The machine is a Whirlpool AA1200. Temperature makes virtually no
difference, The problem is IMO with both the wash and the rinse cycles.
The wash efficiency by use is not significantly above zero! It also has
a novel variety of user unfriendly features which we have only found out
by experience. (Seems like about 40 minutes to achieve a rinse and spin
function on hand washed items!) Some we are still learning( the hard way)!

Hum, make mental note to avoid Whirlpool's if this is really true.
I have a Hotpoint and nearly all my washes are done at 35C.
It always manages to clean everything without any repeat wash.

What washing detergent do you use?
I normally use Persil Bio. I've heard Ecover is complete crap.

--
Andrew Gabriel

On 21 Jul 2005 22:48:41 GMT,it is alleged that
(Andrew Gabriel) spake thusly in uk.d-i-y:

In article ,
Capitol writes:
Pete C wrote:
What make and model machine do you have, and what temperature do you
use? Do you know what the wash efficiency rating is?

The machine is a Whirlpool AA1200. Temperature makes virtually no
difference, The problem is IMO with both the wash and the rinse cycles.
The wash efficiency by use is not significantly above zero! It also has
a novel variety of user unfriendly features which we have only found out
by experience. (Seems like about 40 minutes to achieve a rinse and spin
function on hand washed items!) Some we are still learning( the hard way)!

Hum, make mental note to avoid Whirlpool's if this is really true.
I have a Hotpoint and nearly all my washes are done at 35C.
It always manages to clean everything without any repeat wash.

[snip]

Pretty much the same with Siemens, on the good side that is, it uses
an alarmingly tiny amount of water but cleans great.

--
The follies which a man regrets most in his life are those
which he didn't commit when he had the opportunity.
- Helen Rowland

The machine is a Whirlpool AA1200. Temperature makes virtually no
difference, The problem is IMO with both the wash and the rinse cycles.

Sounds like something is wrong. I find modern machines very effective. In
recent years I've had a Hotpoint Ultima and a Smeg. Both were 'A' rated for
washing performance and I can believe it.

I used an American style top loader at university and it was complete cr*p.
The clothes came out wet and dirty. The "rotating knife" in the middle
chopped the clothes up.

Christian.