At 08:00 PM 7/3/02 -0700, Bill Turner wrote:
>Often, arcs are
>between pieces of hardware not directly in the current path. With HV
>lines, there is such a strong electric field that voltages are induced
>in any nearby conductor such as a brace or even nuts and bolts. If they
>are loose, there will be small arcs between the loose pieces. This kind
>of arc does not burn itself out and will go on it's merry way for years,
>maybe decades. And this kind is also likely to be very erratic. When
>humidity increases, the wood swells and forces the arcing parts together
>and presto, no arcs! Of course, the swelling wood might force the parts
>apart instead of together, and again, no arcs. It all depends.
Amen. The loudest "power-line" noise I have found originated in a
lightning arrestor on a pole in the corner of my yard. Seems that it was
bolted to the pole with two lag screws. A woodpecker had undermined one of
the lag screws so that it had become loose, and the arc was occurring
between the screw and the bracket, neither of which had any physical
connection with the power line.
73, Pete N4ZR
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