Re: steam power

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mike Harrison by way of Terry Fritz <twftesla-at-uswest-dot-net>" <mike-at-whitewing.co.uk>

On Wed, 03 Jan 2001 20:58:16 -0700, you wrote:

>Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<evp-at-pacbell-dot-net>
>
>> 
>> << Lookout for strokes coming back down the spray...
>>     Firemen working near energized HV lines use explicit grounds
>>     on the nozzles to reduce risks.
>> 
>>     best
>>     dwp
>>   >>
>> 
>> Hi Dave P, all,
>> 
>> I don't mean to start an argument, but I have been a firefighter as my
"real"
>> profession for the past 12+ years here in my hometown (Memphis), and I've
>> never heard of "grounding" a nozzle to reduce the risk of electrocution,
when
>> fighting a fire near energized electrical equipment. 
> 
>> >>*It's a safety issue and people are using this technique with coils... -
>> Terry<<
>
>Comment:
>
>	Don't know about the fire fighters, who have enough safety problems
>without worrying about electrocution, but Southern California Edison
>(and presumably all other utilities) routinely wash off the insulators
>on HV transmission lines; I've often seen it done and have been told
>(electric power transmission class in grad school) it's done with the
>line hot.  Nozzle and nozzle holder are on top of a cherry picker
>mounted on a truck. and brought up to perhaps from the insulators.  In
>at least once case the insulators being washed were on the 220 kV HV
>line which, as far as I know, was the only source of power for the area
>I was in, which would tend to verify that the lines were not disabled. 
>Someone here must have better knowledge as to what is really done.

I have seen some info on this in an old engineering book. Apparently
as well as using deionised water and a grounded nozzle,  the trick is
to use a comination of nozzle type and distance which ensures that the
water jet has broken up into seperate droplets by the time it hits the
HV.