Date: Mon Aug 6 20:38:39 2007

Author: Gordon Shepherd

Subject: Re: High Power or is it High Voltage.

Post:
There might be two sources. 1) the corona effect: multi conductors (2
in this case) are used in extreme HV lines to reduce the corona that
occurs with single (and sharp) conductors. Often you see 3
conductors. 2) the static generated between the continuously rotating
blades and the air. Helicopters usually touch the water before rescuing
someone from the ocean to discharge the buildup.
Gordon
Douglas Johnson wrote:

>
>
> I think it is the potential difference between the two, much like
> standing on a isolated platform and touching a Van de Graaff
> generator. The sharp point is the only way to bring both objects up
> to the same voltage without getting zapped by by a capacitive
> discharge (or lightning bolt) between the wires and the helicopter.
> Once they are the same voltage, then the risk of being zapped is
> lessened. As far a birds go, they would probably die before landing.
> The metal thread with fireproof fabric on the guy walking the power
> lines must keep him from catching fire. What an interesting film
> clip. I wonder what he had to do on the power line that was so
> important? Maybe to inspect the insulation on the towers close up. I
> also wonder what the humidity and wind condition has to be like before
> doing such a risky job. ...Doug J.
>
>
>> What is the reason for those big sparks?
>>
>> That is why you can see birds on HV lines?
>>
>> Thanks
>>
>>
>> --- Richard Heckathorn wrote:
>>
>>> Greetings,
>>>
>>>
>>>
>>> This information just came from another list
>>> serve. It is worth looking at.
>>>
>>>
>>>
>>> http://www.glumbert.com/media/highpower
>>>
>>>
>>>
>>> Enjoy
>>>
>>>
>>>
>>> Dick
>>>
>>>
>>>
>>>
>>>
>>> Helping teachers who facilitate, motivating
>>> students who learn.
>>>
>>> Dick Heckathorn 14665 Pawnee Trail Middleburg
>>> Hts, OH 44130 440-826-0834
>>>
>>> www.cvcaroyals.org/~rheckathorn/
>>>
>>> Adjunct Physics Teacher - Baldwin Wallace College
>>>
>>> Physics is learning how to communicate with ones
>>> environment so that it will talk back.
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>> ____________________________________________________________________________________
>>
>> Fussy? Opinionated? Impossible to please? Perfect. Join Yahoo!'s
>> user panel and lay it on us.
>> http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7
>
>
>

Back