Re: Oil insulated secondaries (fwd) (Are they worth it?) (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Tue, 11 Sep 2007 08:54:48 -0700 (PDT)
From: J. Aaron Holmes <jaholmes@xxxxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Oil insulated secondaries (fwd) (Are they worth it?) (fwd)

I'm sure it would work great, but it would also be a
devil to repair if anything did actually go wrong.  I
wonder what the transformer people do to repair those
PTs when they "die" ...?  I've got a few of those sort
of PTs in my PT collection too.  There are probably a
great many interesting insulation techniques for Tesla
secondaries which, like oil, are probably not
especially worthwhile but would definitely be fun to
do.  This is probably another of those.  Heck, you
could take a whole tabletop coil system and
encapsulate it in a plyurethane block with just the
topload and power cord sticking out ;-)

Cheers,
Aaron, N7OE

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> 
> ---------- Forwarded message ----------
> Date: Tue, 11 Sep 2007 03:38:53 -0700 (PDT)
> From: Yurtle Turtle <yurtle_t@xxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Oil insulated secondaries (fwd) (Are
> they worth it?) (fwd)
> 
> I just checked my cutsheet and I stand corrected.
> I've
> always referred to my two 25 kV 125 kV BIL PT's as
> "epoxy encapsulated" when in fact they're
> "polyurethane resin encapsulated".
> 
> Let me restate my question...
> 
> Why not build the oil-filled secondary, but instead
> of
> filling it with oil, encapsulate it with
> "polyurethane
> resin"?
> 
> Adam
> 
> --- Tesla list <tesla@xxxxxxxxxx> wrote:
> 
> > 
> > ---------- Forwarded message ----------
> > Date: Mon, 10 Sep 2007 09:53:09 -0700 (PDT)
> > From: J. Aaron Holmes
> <jaholmes@xxxxxxxxxxxxxxxxxx>
> > To: Tesla list <tesla@xxxxxxxxxx>
> > Subject: Re: Oil insulated secondaries (fwd) (Are
> > they worth it?)
> > 
> > Epoxy coating is not about electrically
> insulating,
> > it's about physically protecting and preventing
> the
> > windings from sliding off.  That's it, really. 
> Oil
> > does neither of these things, and is instead all
> > about
> > electrical insulation.  HOWEVER, whether it's any
> > advantage at all depends on what other aspects of
> > your
> > design you hold constant, and given that most of
> > these
> > other aspects are usually controllable in such a
> way
> > as to avoid the necessity of oil insulation, I'd
> > have
> > to agree that oil insulated secondaries are
> > moderately
> > to extremely silly in most cases.  They are
> > undoubtedly "interesting" and "cool", though.  I
> > loved
> > the look of Terry Blake's coil, and decided to add
> > my
> > own twist".
> > 
> > All else being equal, I'd expect oil insulation
> > would
> > make the secondary less susceptible to secondary
> > breakout, primary-secondary strikes, racing arcs,
> > and
> > internal arcing.  This, in turn, might permit the
> > use
> > of higher-than-average coupling, larger toploads
> > (which would otherwise tend to encourage secondary
> > breakout), and generally a bit more power,
> achieving
> > a
> > higher-than-average streamer-to-secondary length
> > ratio.  But we'll see!!  Again, I doubt if it's a
> > very
> > practical way to accomplish these things, but it
> is
> > nonetheless a fun twist.
> > 
> > Cheers,
> > Aaron, N7OE
> > 
> > --- Tesla list <tesla@xxxxxxxxxx> wrote:
> > 
> > > 
> > > ---------- Forwarded message ----------
> > > Date: Sun, 9 Sep 2007 18:22:33 -0700 (PDT)
> > > From: Yurtle Turtle <yurtle_t@xxxxxxxxx>
> > > To: Tesla list <tesla@xxxxxxxxxx>
> > > Subject: Re: Oil insulated secondaries (fwd)
> > > 
> > > I'm just curious why oil would be better than
> > simply
> > > potting it in epoxy. I realize it would look
> > cooler.
> > > Seems like an oil tight seal would be harder to
> > > accomplish than one that only needs to hold up
> > until
> > > the epoxy hardens.
> > > 
> > > Adam
> > > 
> 
> 
> 
>      
>
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