Re: Single-bushing 14.7kV pigs. Thoughts?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "J. Aaron Holmes" <jaholmes-at-silicon-arcana-dot-com> 


Yeah, the idea had crossed my mind, but the insane
120V currents involved (even just to magnetize two
15kVA cores) makes me shudder.  15kVA is 3x what I
wanted, but was the smallest available, I'm afraid.
Urban utilities just don't use sizes like 5kVA and
10kVA anymore, according to my source.

That clear-coated pig is super-cool, BTW!

Regards,
Aaron

--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > Original poster: Sean Taylor <sstaylor-at-uiuc.edu>
 >
<SNIP>
 > The other option, since you have two of
 > them, is to run each of
 > them off of 120 V (across the 240 V winding), and
 > hook the outputs in
 > series with the cases grounded together a la NSTs.
 > This will give you two
 > HV output bushing, but it won't be floating WRT to
 > ground as a true double
 > bushing pig would be.  If you really want to go
 > crazy, you could take the
 > pig apart, and remove the wire from the HV side that
 > is connected to the
 > case, get another bushing and hook that up . . . but
 > thats a lot of work in
 > a big oily mess.  Or you could do what Dave Leddon
 > did, and recase the pig
 > in plastic:
 > http://nick_tesla.home-dot-comcast-dot-net/TheVisiblePig.jpg
 >
 > Sean
 >
 > >Original poster: "J. Aaron Holmes"
 > <jaholmes-at-silicon-arcana-dot-com>
 > >   The price was $100 for a 14,760V 15kVA unit, the
 > >smallest unit they had.  I was so ecstatic, I
 > bought
 > >two for twice the price :)
<SNIP>
 > >Trouble is, they're the single-bushing sort.
 > >
 > >Now, this may or may not be a big deal; I've been a
 > >long-time lurker on this list, but I've never
 > gotten a
 > >good feeling for exactly what the downside is to
 > >having only a single HV bushing.  If I wire up the
 > >outer two bushings on the LV side and ground the
 > case,
 > >can't I just treat the case like the other HV
 > bushing?
<SNIP>
 > >Regards,
 > >Aaron
 > >