Re: safety gaps on capacitors

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 8/8/01 9:53:26 AM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Parpp807-at-aol.
> com>
>  
>  Anyone,
>  What would be the effects of shorting an oil filled capacitor?
>  If an oil filled capacitor arcs over internally is it ruined?
>  What happens to the oil dielectric? Is it carbonized?
>  
>  I am referring to an oil filled capacitor  where the oil is the only 
>  dielectric
>  separating the plates of the capacitor.
>  
>  Cheers,
>  Ralph Zekelman

Ralph,

I have an oil dielectric variable homemade capacitor that I use
for certain TC tests and tuning.  I've caused it to arc internally
a number of times.  This carbonizes the oil at the spot of the
arc-over.  It's important to mix or stir the oil to let the carbon
spread evenly though the oil.  Just letting the cap stand overnight
also permits the carbon to diffuse through the oil, and the cap
will be almost as good as new.  (I was not able to notice any
increased tendency to arc-over.)  However, I suspect one would
not want to let the cap arc internally too many times through
the oil dielectric, because too much carbon would build up, 
causing the breakdown voltage to be compromised.

John Freau