RE: variac size and flashover

>Original Poster: pmathus-at-learningco-dot-com 

>2 questions for the gurus:
>1)  How big a variac do i need? 5 amps?  15 amps? I'm going to be 
>running a 12kv 60ma NST.
With my 15KV/60MA NST, I pull over 20 Amps from the wall.  This seems to be
very high and atypical, but it is real.  My 15A Variac handles it just fine.
>2) What's the recommended distance between the first turn of the 
>primary and the secondary to prevent flashover?  I was thinking 2", 
>(for a 6" secondary) but now i'm wondering if that's too much. . .
1 inch should be fine, just make sure there are no sharp edges on the
primary to concentrate the e-field and precipitate a breakdown.  I've used
as small as 0.8" with that NST with no problems.
> paul mathus

Regards, Gary Lau
Waltham, MA USA