Good points, as usual, Tom. Corona --besides greatly reducing the breakdown voltage-- can also generate ozone, which can gradually break down some dielectric materials. When I worked at Owens-Illinois in Perrysburg Ohio in the late 70's, they used large insulated conductors to feed 12 kV 3 phase from the substations into the building. After a few years, ozone finally deteriorated the rubber insulation to the point that it failed catastrophically. A spectacular arc, explosion, and a lot of damage and downtime was the result. (Bob Wacke WA8SHH probably remembers that.) Those HV cables are now made differently, some with a static drain on the outer cover.
73, Mike www.w0btu.com On Tue, Oct 1, 2013 at 11:10 AM, Tom W8JI <[email protected]> wrote: > ... years of corona will slowly eat away the dielectric... > _________________ Topband Reflector
