Cheat your electric meter
Babak Sehari
>The recent discussion of the possibility of "cheating" an electric meter
>has been really interesting, but I find it odd that everyone assumes that
>if they have a power factor that is is not unity, they will be undercharged.
>A non-unity power factor will make the "apparent power" appear HIGHER
>than the real power that is consumed. Measuring RMS current and multiplying
>by RMS voltage gives apparent power. A load of non-unity power factor
>will send power back into the line during part of each cycle, and a simple
>volt-ampere meter will not see that. Of course we already have been told
>that the power meters do measure real power, so this point is moot.
>I've also heard that power companies hate low power factors not just
>because the overall power factor of the network must be roughly balanced,
>but also because high currents cause resistive losses in transmission lines
>regardless of their phase to the voltage. So a customer with a low
>power factor will cause more transmission line losses than another customer
>with a high power factor drawing the same amount of real power, and unless
>the first customer is penalized for his power factor, the power company
>has to pick up the tab for the extra line losses he is causing.
>Markus Wandel
Also not to mention the problem of standing wave on the transmission lines
that causes damage both to individual costumer, who happen to be in the peak
position, and to the power companies equipment. As I heard, if the power factor
is not near unity, power company warns you first; and if you do not correct it,
they cut you off.
With highest regards,
Babak Sehari.
Arno Hahma
>by RMS voltage gives apparent power. A load of non-unity power factor
>will send power back into the line during part of each cycle, and a simple
>volt-ampere meter will not see that. Of course we already have been told
>that the power meters do measure real power, so this point is moot.
Out of curiosity, I tried another approach: I put a strong permanent
horseshoe magnet on the power meter. It slowed down the disk rotation
by about 45 %. If I turned it around, it would weaken the field of the
magnet inside the power meter and accelerate the disk by 45 %.
I did take the magnet away, honest ;-).
ArNO
2
Brian Vargyas
issue of Radio Electronics. In the Hardware Hacker section pages 78-79, Don
Lancaster talks about measuring REAL power, and the correct way it should be
done....Very interesting article... It will answer quite a few of your
questions about leading and lagging signals....etc...
Brian Vargyas
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Michael G. Katzmann
>
< Stuff about Power Factor deleted >
>
>Also not to mention the problem of standing wave on the transmission lines
>that causes damage both to individual costumer, who happen to be in the peak
>position, and to the power companies equipment.
Come on.... a quarter wavelength at 60 Hz is 5000 kms!!
Do you really believe that the power grid is a matched transmission system??
--
Michael Katzmann > Broadcast Sports Technology Inc.
~~~~~~~~~~~~~~~~ < Crofton, Maryland. U.S.A
Amteur Radio Stations: >
NV3Z / VK2BEA / G4NYV < opel!vk2bea!mic...@uunet.uu.net
Babak Sehari
>In article <sehari.6...@du139-203.cc.iastate.edu> seh...@iastate.edu (Babak Sehari) writes:
> >
> < Stuff about Power Factor deleted >
> >
> >Also not to mention the problem of standing wave on the transmission lines
> >that causes damage both to individual costumer, who happen to be in the peak
> >position, and to the power companies equipment.
>Come on.... a quarter wavelength at 60 Hz is 5000 kms!!
>Do you really believe that the power grid is a matched transmission system??
True, but what you are dealing here is the lumped element Transmission line
not regular transmission line.
-----^v^v^---OOO---------------OOO--v^v^v^--------
R L | | L R
< |
R > = C
< |
| |
-------------------------------------------------------
This lumped elements are costumer's houses, power company's transformers
and many not ideal properties of power company's transmission line.