Re: Wiring consumer unit and shore power

In article <t8YNh.56470$mJ1.29497@xxxxxxxxxxxx>,
wilburhubbard@xxxxxxxxxxxxxxxx says...

"Duncan McC (NZ)" <hard@xxxxxxx> wrote in message
news:MPG.20725e4f5c2e6d3e989763@xxxxxxxxxxxxxxxxxxxxxxx
In article <CcXMh.15781$s8.10382@xxxxxxxxxxxx>,
wilburhubbard@xxxxxxxxxxxxxxxx says...

"Duncan McC (NZ)" <hard@xxxxxxx> wrote in message
news:MPG.206f016676f3bb7a989760@xxxxxxxxxxxxxxxxxxxxxxx
In article <fcGLh.66687$_w.22818@xxxxxxxxxxxx>,
wilburhubbard@xxxxxxxxxxxxxxxx says...

"Geoff-Uphill" <geoff.rich@xxxxxxxxxxxxxx> wrote in message
news:1174351058.154551.243110@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Don't see its any
different to using any 240v appliance on the end of a 25m lead ?

I guess that means England uses 240VAC? Why do you guys use twice
as
many volts as you need to run appliances? Here in the USA most
stuff
runs on 120VAC except for some of the bigger things like welders,
etc.
We do the same jobs using half as much electricity.

You guys use twice the electricity you need to get the job done
and
then
you complain about the United States contributing more to global
warming
gasses? How about getting your own house in order?

On second thought, keep up the good work. Melt the north and south
poles
and there will be more places to sail to.

I like your ideas on the North and South poles.

Can I suggest that your theory on voltage is flawed. Surely at
school
you learnt:
V(olts) = IR (or I = V/R) and P(ower) = IV
Could we assume that house wiring around the world is, largely, the
same. This means R is the same. I'll let you do the rest :)

--
Duncan

The way I understand it is voltage can be likened to pressure. If you
have an air tank pressurized to 240psi and one the same size
pressurized
to 120psi you can get twice as much air out of the 240psi tank. If
you
don't need 240psi to inflate your car tires to 32psi,for example, and
inflating them reduces the tank pressure to 180psi then you could
have
inflated the tires using the 120psi tank and had plenty enough air to
get the job done.

Now, the key is this. It takes more energy to fill an air tank to
240psi
than it takes to fill one to 120psi. So why waste energy filling the
tank up to 240 psi when you only need less than 120psi to get the job
done.

Now, take the same thing with electricity. Why fill (pressurize) the
wires with 240 volts which takes extra energy when you can fill them
with 120 volts and do the necessary work? As voltage goes up so does
impedance which means energy turned to heat and is wasted even more
in
transmission. Try explaining that with some dumb formula.

There's just one problem with your analogy. Say you take yer bike
pump
and pump it with your finger over the end. No heat (yet). It's not
until you let air bleed out (analogous to 'I' (current)) that heat is
generated. Yer with me?

So it's not the voltage that is 'wasted' as heat, it is the current.

Given the equation prev. mentioned: P = V^2 / R...

it is in fact your American system that is WORSE than the British, New
Zealand or Aussie - in fact every country bar America, Japan and some
south american countries (I think that's about it).

Doing the maths, you should quickly conclude you're about four times
worse off!

What voltages are used to get the power from your generation sources
to your homes? 1 volt? Less?
You work out why they use *large* voltage values (I've done it for
you already mind).
assuming the resistive value of wiring (anywhere on the planet) is
about the same; therefore the higher the voltage the less the
current (to produce the same power), and therefore less wastage
(current that is wasted as heat in the wiring).

--
Duncan


But you've got to remember the power must be produced in the first
place. Given a fossil fuel powered generator it takes more fossil fuel
to produce 10 amps at 240 volts than 20 amps at 120 volts. This is due
to the energy loss caused by heat (resistance). Everybody knows you can
move about ten times the water in a four inch pipe as you can in a two
in pipe. Electricity makers use hot skinny little wires instead of nice
big fat cold wires that would transmit the power more efficiently.
Water companies know it's more efficient moving the same volume of water
at lower pressure in a four inch pipe than at higher pressure in a two
inch pipe. Electricity producers ignore all this because of the
economics of installing a decent transmission line. They eschew the
bigger pipe for the higher pressure but they pay dearly bumping that
pressure up there.

You wankers are clueless when it comes to electricity, it seems.

Thank you. Perhaps you should consider a different analogy (vs. the one
you used) - think of a wire like a river.

The resistance is a factor of the width of the river. And the speed of
it is governed by the steepness of the river (voltage). The power
passed is of course the flow past a point (a factor of voltage and
resistance).

Surely that is easy to understand.

I have been trying to say that house wiring is probably very similar
around the world. So the width (or resistance) is the same.

In your latest post (above) you've managed to get it round the wrong way
*again*.

Perhaps a factor you don't understand is 'flow'. When you bump an
electron at one end of a wire, the electron down the other end moves
(pretty much at the speed of light). Now this is different from current
- which is where your analogy (and mine) fall short. So sorry you can't
use your "water pumping example" as an analogy. Voltage does not
produce the friction (resistance), current does.

So high voltage is good, very good, for transmitting power. It is bad,
when the voltage values get high, and factors such as insulation and
radiation losses come into play.


re: Given a fossil fuel powered generator it takes more fossil fuel
to produce 10 amps at 240 volts than 20 amps at 120 volts.

This is plain wrong:

Electricity is generated by creating 'base unit's' - charge (coulombs).
The difference between charges is the potential difference (measured in
volts). When charge flows (eg. along a wire) it is a current (measured
in amps). The rate in which it is used (or made) is measured in watts.

I believe you Americans are charged for the watts (kilowatts) you use,
not the voltage (or you'd all have the same bill every month!).

I = V/R (ohms law)

P=IV
so P = V^2/R
and P = I^2 x R

I'm not sure of you can comprehend what that means. In terms of the US
system vs. 240v - it is *clear* that you will loose more power as a
factor of resistance. (You *can* see that right?). About four times as
much indeed!

You could of course, run 'big wires' in your houses in the US - given
the price of metals in the last two years (particularly the last year)
going up - this is gonna be expensive! (particularly when you talk
copper).

Have a read up here:
http://en.wikipedia.org/wiki/Electrical_power_industry
http://en.wikipedia.org/wiki/Alternating_current
http://en.wikipedia.org/wiki/Electric_current
http://en.wikipedia.org/wiki/Electric_power

Perhaps you should stick to your Jim Beam.

--
Duncan
.

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