Re: Cap Failure

To: tesla-at-pupman-dot-com
Subject: Re: Cap Failure
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
Date: Thu, 17 Oct 1996 07:03:07 -0700
Tesla List wrote:
> 
> >From ed-at-alumni.caltech.eduWed Oct 16 22:41:28 1996
> Date: Wed, 16 Oct 1996 16:36:56 -0700 (PDT)
> From: "Edward V. Phillips" <ed-at-alumni.caltech.edu>
> To: tesla-at-pupman-dot-com
> Subject: Re: Cap Failure
> 
> Question:
>         Was the failure EXPLOSIVE, or just due to high internal
> pressure?  In other words, could there have been air in the capacitor
> which helped oxidize fuel (oil vapor) in a conventional explosion,
> or was it a case of a relatively high-energy spark vaporizing oil
> and expanding the case without any burning?  Also, was the capacitor
> oriented horizontally or vertically?  The latter would seem to make sure
> there was oil all along the casing (at least between capacitor sections),
> but would certainly be inconvenient.
> Ed

Ed,

There definately was air in the cap, since you could hear the oil
sloshing in the cap if you rotated it. Don had rotated the cap
periodically as the CP folks instructed since he bought it. The
capacitor was oriented horizontally during all runtimes. Its really
difficult to say if this was an explosion or not - there was a yellowish
flash (which may have simply been the electrical flash "seen" through
the outer PVC wall when the cap openned). The sound was more like a loud
"pop" than a bang. 

Once the lights were turned back on, there also was a little wisp of
smoke or steam coming out of the remaining capacitor body. The odor of
the oil was different than Shell Diala-X or AX, but I don't know for
sure if it was petroleum-based or something more exotic. There was no
obvious evidence of ignition anywhere - no trace of carbon tracks,
blackenned oil, etc. Since Don will be sending the cap back to CP, they
MAY be able to tell him what actually caused the failure (if they're
willing to share the info...). 


-- Bert --