Re: buying a pole pig

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "J. Aaron Holmes" <jaholmes@xxxxxxxxxxxxxxxxxx>

I think you missed my point.  I have two
single-bushing pigs, both of which have "14760/25565Y"
on the nameplates.  Both are from different
manufacturers, so I beg to differ on the "single
voltage" thing!  In fact, I have yet to see a
single-bushing pig that *isn't* rated like this
(doesn't mean they don't exist, of course).  Anyway,
in this case, one clearly *cannot* refer to 14760 as
the "delta" voltage because delta means
phase-to-phase.  A single-bushing transformer will
never be connected phase-to-phase, only
phase-to-neutral.  I added "in the wild", because some
coilers with single-bushing pigs float the cans,
although recent TCML opinion is that doing so (or
going to great lengths to obtain a double-bushing pig)
isn't as important as once believed.

So, in short, if you hear something like
"7200/12470Y", don't assume double-bushing.  Further,
I'd call 7200 the "phase voltage", not the delta
voltage.  Though the "phase" and "phase-to-phase"
voltages are the same in a delta connection, one
cannot delta-connect a single-bushing pig.

Regards,
Aaron, N7OE

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

> Original poster: Don Murray <don@xxxxxxxxxxxxxxx>
>
> Aaron,
>
> It doesn't matter if that transformer is in the
> wild, up a pole or in
> your garage, that nameplate means that if you are
> going to attach
> that transformer to a 7200 phase to phase volt
> system you are going
> to connect it delta, and if you are going to connect
> it to
> 12470  phase to phase volt system, you're going to
> connect it Y. That
> is the only thing it can mean and because of that
> you know it's going
> to be a 2 bushing transformer. If it was a 1 bushing
> transformer it
> would only have one voltage.
>
> Tesla list wrote:
>
> >Original poster: "J. Aaron Holmes"
> <jaholmes@xxxxxxxxxxxxxxxxxx>
> >In the wild, 7200/12470Y does *not* imply that a
> 7200V
> >delta connection is ok.  You also need the pig to
> have
> >two HV bushings.  If it has only one, then a delta
> >supply would imply that the can is "hot", which is
> no
> >good.