cap explosions

To: mail11: ;
Subject: cap explosions
From: pierson-at-msd26.enet.dec-dot-com
Date: Fri, 18 Oct 96 13:21:44 EDT
Cc: pierson-at-msd26.enet.dec-dot-com


In general (yeah, there are exceptions) a fuel and an oxidizer are needed
to get a chemical explosion.  The caps being (nominally) sealed, there is
little air in there.  Which brings up:

	...air inside... sloshing....

Has the manufacturer said there is air?  Is it air, or something else?
(and air is motly not_oxygen anyway...)  I'm not arguing, just wondering.

Has anyone asked about "why no balancing resistors?", that information, if
available, would be verrrrrry interesting.  Again, just wondering...

My first suspicion, even of a fairly vigorous event, would not be of a chemical
explosion, per se, but of catastophic electrical induced failure.

As to the possibility of case puncture, wood is a fairish conductor (unless
treated), at tesla-type voltages.  (Pix of hv labs show caps, etc, mounted on
explicit insulators.)  Even if the 'power circuit' is 'floating' (not explicitly
ground referenced) everything has stray capacity to something, leading to
voltages in unaticipated places...  And tesla primary circuits are notorious
for odd resonant voltages showing up in 'the wrong place'.

	regards
	dwp