RE: Re: Power saving unit?

["Phil Harris" <phil@xxxxxxxxxxx>]

*chuckle* I did start to type a brief reply to the original post but
then
gave up as there isn't a brief reply. My last employer (Schneider Electric)
had entire divisions of the company dedicated to power factor correction on
an industrial scale where active power factor correction systems would be
applied to systems where you had a large number of very similar loads (say,
multi story carpark lighting) but nowhere in their catalogue of products
did
they have a bit of kit with the description "shhhhh - keep this a
secret but
if you bolt in this box and it will automatically save you money no matter
what the mishmash of loads are hanging off it"...

http://powerelectronics.com/power_management/motor_power_management/power-fa
ctor-correction-0507/

seems to be a reasonable attempt to explain power factor correction as a
general concept.

Myself, I'd probably say that if you want to buy one of those things then
buy one and you can keep the instructions for it next to the instructions
for the metal balls that you drop into your fuel tank to increase the
combustion efficiency of the petrol, the magnets that you clip to the water
pipes to soften your water, the electric fan "turbo" units that
you put of
your cars air intake to give you more power and the sky hooks and left
handed screwdrivers that the guys had you go fetch on your first day at
work... :-D

Phil

> -----Original Message-----
> From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf
> Of Ian Lowe
> Sent: 08 August 2009 05:11
> To: ukha_d@xxxxxxx
> Subject: [ukha_d] Re: Power saving unit?
>
> --- In ukha_d@xxxxxxx, Vargster <vargster@...> wrote:
> >
> > I think this http://www.powergard.ca is similar tp
the one that
> appeared on
> > the BBC news website.
> > Any chance it might sctually work then? And thereby save on the
elecy
> bill?
> >
> > Lee
>
> I'm sure one of the electricians can explain this better, but it seems
> to be trying to alter the power factor - which is a 'fake' measure of
> your consumption..
>
> power factor is a hound of a thing to explain...
>
> basically the power numbers you would get in a DC environment, where
> simple rules like power = voltage * current hold true, and the AC
world
> are different.
>
> AC voltage traces out a sine wave - the current flowing in the circuit
> also follows a sine wave.. what's a little counterintuitive is that
the
> current and voltage sine waves are not always in sync.
>
> if your circuit only contained simple components with just resistance
> the current and voltage would be in sync.
>
> As soon as you add inductance and capacitance into the circuits, then
> the current and voltage slip out of sync... and the calculation of the
> true power consumed becomes more complex - and the ratio between your
> theoretical Volts * Amps power, and the *actual* power being consumed
> is your power factor.
>
> Power meters make assumptions about your power ratio, as do
electricity
> providers - devices like this may reduce a bill in the short term (bt
> almost certainly not by much - a few percent tops), but they won't
> affect the actual amount of power being used in any real sense: the
> same amount of coal/gas/whatever will need to be used to generate the
> same amount of juice - it will just read differently on the meter in
> your premises.
>
> If this is pants, please - I'd welcome a better explanation from
> someone who relaly 'gets' power factor. I always feel that my
> understanding is a bit tenuous...
>
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>


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