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Re: this was probably really stupid



Original poster: Edward Wingate <ewing7-at-rochester.rr-dot-com> 

Tesla list wrote:
 >
 > Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
 >
 > Ed:
 >
 > I have always wondered how these long distance EHV lines avoid producing
 > excessive corona.
 >
 > The cables do not appear to be very large in diameter --- perhaps an inch or
 > two at best.  With that small radius and diameter, why don't they emit
 > tremendous corona?
 >
 > With corona inception potential around 67 kV per inch (30 kV/cm) they should
 > be glowing a lot with their small diameters.  Especially in rainy weather.
 >
 > Dr. Resonance
 >
 > Resonance Research Corporation
 > E11870 Shadylane Rd.
 > Baraboo   WI   53913

<snip>

Hi DC,

That's about right for the wire size and it's bare.

That's why they "bundle" two, three or 4 conductors to increase the
effective radius and when you see 4 bundled conductors used for a 765 KV
line you can't tell from the ground that the distance on each side of
the square bundle is 3 or 4 feet.

Another quote from page 4-22 of "The Lineman's and Cableman's Handbook"
"The use of bundled conductors and appropriate hardware on AC EHV and
UHV lines keeps corona to acceptable limits if the equipment is
installed correctly.

Acceptable limits being the key words. I'm sure that the losses in rainy
weather are considerably increased.

With a typical ampacity on a 765 KV line of 3890 amps, I want to see the
inside of the step up transformer! Not only high voltage, but HUGE
currents, it boggles the mind! With voltages like that, who needs a
Tesla coil?

The parking lot at the Kodak Riverwood training center a short distance
from here is directly under two 345 KV three phase transmission lines
and the lines are no more than 30 feet over the lot. I took Sue Gaeta
and Tony DeAngelis there the day before the Teslathon last year. Ask Sue
if she could hear the corona. :^) They used to warn people not to put up
umbrellas under those lines when it was rainy or misty/foggy. DUH!

Just call me cinder,

Ed Wingate RATCB