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Re: Cap Failure
Tesla List wrote:
>
> >From MALCOLM-at-directorate.wnp.ac.nzMon Oct 14 21:29:04 1996
> Date: Tue, 15 Oct 1996 09:00:46 +1200
> From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
> To: tesla-at-pupman-dot-com
> Subject: Re: Cap Failure
>
> Hello all,
> I take it from this post there has been another CP cap
> failure....
>
> > >During the next run, power was adjusted to about 80% (about 112
> > >volts) on the 15 KV 120 MA neon tansformer source, with good coil
> > >output, when after about 20 seconds one end of the capacitor was
> > >suddenly and explosively blown off with no prior warning. A loud "pop"
> > >and a yellowish colored flash were heard and seen, and capacitor oil
> > >was ejected in the immediate area.
>
> and that the failure is caused by carbon tracking inside the case?
> Would somebody please fill me in on the details.
>
> Thanks,
> Malcolm
> <Major snip>
Malcolm,
Welcome Back!
Probably not carbon tracking _thru_ the case in the latest failure,
since the cap was resting on a thick HDPE sheet. In Richard Wall's case,
thru-wall carbon tracking may have been a contributing factor. I've
asked him if he had the cap resting on a conductive surface while
operating the coil.
In the latest failure, no obvious cause was apparent, but clearly
something caused significant pressure rise in the cap. Closer
examination will be done, and the capacitor will hopefully be
salvageable.
-- Bert --