grounding bombarders (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: List moderator <mod1@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Mon, 11 Dec 2006 17:22:36 -0600
From: David Rieben <drieben@xxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Cc: David Rieben <drieben@xxxxxxxxxxxxxxx>
Subject: grounding bombarders

Hi all,

I have  a question regarding a bambarder transformer.
I have a 7.5 kVA, 240 v/ 30 kV dry transformer unit that
weighs about 175 lbs. The HV secondary output is 
completely isolated from the core and the primary coil.
It runs very quitely in this fashion, even when the pri-
mary is powered by the full rated 240 volts and the 30
kV output of the secondary is left open circuit (there
is virtually no audible high voltage corona "hiss").
However, if I ground  one of the HV secondary outputs 
to the core, it does make a bit of a corona hissing 
sound, not bad, but definitely there. My question is 
is it ok to ground one side of the HV output as I have
to assume that corona is generally a "bad" thing? Would
the "hiss" improve if I were to submerge the transformer
in oil, even though this transformer is definitely designed 
to run "dry" - but most likely with the HV output completely
isolated? Thanks in advance for any responses.

David Rieben