Re: insulation testing

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

Original poster: "Sean Taylor by way of Terry Fritz <twftesla-at-qwest-dot-net>" <taylorss-at-rose-hulman.edu>

The corona you're seeing is most likely from capacitive coupling - the
insulators is acting slightly as a capacitor, and there is some current that
is flowing because of that.  The corona is just the current going through
the air to the insulator.  To see if this is right, you'll have to look at
the PF of the HV . . . don't know if you have a way to look at the current
and voltage at those levels though.  But, if you do, then a 90 degree phase
difference would tell you that it is capacitive coupling.

You'll also get a difference in E-field with different electrodes.  A pointy
electrode will have a higher E-field, while a rounded terminal will spread
it out further, hence a toroid or spherical topload.

I would just go by manufacture's specs for voltage standoff, and if youre
making a capacitor, go with about double your NST peak voltage, or about 3
times RMS, for safety.

----------------------
Sean Taylor
The Geek Group
G-2 #1204
Because the geek shall inherit the Earth! (c)
www.thegeekgroup-dot-org