Re: Free Air Arcing of electricity (fwd)

[Larry Cartwright <exit60@IA4U.NET>]

William Beaty wrote:
> someone needing expertise in HV arcs to power lines
> "I recently participated in a fatality investigation where the electrical
>  charged "free air arced" across a gap from high voltae power lines (33,000
>  V) to the nose of a truck mounted crane."
> "I was wondering if you could help pointing me to find out where to gather
>  more information on this."
> "regards | Brent Paterson | Safety Manager | BHP Building Products Australia"

(1) May I suggest a search using the <http://www.google.com/>
    search engine with the keywords "high voltage research".
    Among other things, this points out that Brent has available
    to him "locally" the University of Queensland's LHVI laboratories
    which bills itself as "a premier centre of expertise in Australia
    and as among the best University facilities of their kind in the
    world."  <http://www.elec.uq.edu.au/~saha/hvlab/hvl.html>

(2) The IEEE publishes standards that deal with HV safety, for example
    IEEE Standard 510-1983 (HV/HP Testing) includes

    "7.1 All objects at ground potential must be placed away from
         all exposed high voltage points at a minimum distance of
         1 inch (25.4 mm) for every 7,500 Volts, e.g. 50 kV requires
         a spacing of at least 6.7 inches (171 mm)."
    "7.2 Allow a creepage distance of 1 inch (25.4 mm) for every
         7,500 Volts for insulators placed in contact with high
         voltage points."

    <http://standards.ieee.org/catalog/contents.html>

And relatedly, in the department of morbid spectacular HV events, if you
would like to see photos of a guy who was for one brief shining moment
the world's dumbest human being, visit
<http://www.drmegavolt.com/underpages/warning.asp>.

Best wishes,

Larry
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Larry Cartwright  <exit60@ia4u.net>
Physics and Physical Science Teacher
Charlotte HS, Charlotte MI USA
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