RE: grounding bombarders (fwd) - I Wouldn't (fwd)

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Original poster: List moderator <mod1@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Tue, 12 Dec 2006 16:19:00 +0000
From: Jack King <ekklekktikk@xxxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: RE: grounding bombarders (fwd) - I Wouldn't




>From: "Tesla list" <tesla@xxxxxxxxxx>
>To: tesla@xxxxxxxxxx
>Subject: grounding bombarders (fwd)
>Date: Mon, 11 Dec 2006 17:27:08 -0700 (MST)
>
>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").

It's a HYDE / Willick, and one of the best of the best dry Bombarders - 
capable of sustained current well beyond the tag ratings... But even it will 
have it's limitations, and wouldnt advise earthing one terminal, as while 
the BIL level is high - it's not high enough...and from what I have learned, 
I wouldnt park it in an oil bath, as over time, the oil may interfere with 
the HAPTZ varnish on both the pri and sec. I only place transformers that 
are wound with cotton or fiberglass insulated wire in oil...


Feel free to contact me off list. I know a bit about these, as I purchased 
the remaining inventory and tooling, etc from Willick ENgineering, as they 
shifted out of Neon and mostly design/fabricate/repair larger X-ray and 
other medical transformers now....

Jack King -801-605-5136


>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
>
>

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