> There is still a lot of so-called corner grounded Delta in
> St. Louis, Mo and
> other older sections of some other towns. This arrangement
> causes havoc
> with all kinds of things, from computer equipment to
> remodeling and adding
> juice, because it is obsolete. You probably won't see corner
> grounded delta
> in a new system ever.
>
> Modern systems do run a specifically grounded wire with the
> phase wires, but
> some of these WWII relic corner grounded delta systems didn't. If the
> connection of one phase to ground fails, the whole system can
> begin to float
> up to high voltage, say from leakage from a high voltage
> transformer or even
> static. Often this ground connection is just a slim chunk of
> thin wire to a
> ground rod. You could literally have 440V in a plant, but each leg is
> several thousand volts to ground. Eventually a motor or two fails on
> insulation, and the whole thing goes up in smoke without ever
> blowing a
> breaker, or motor cases become live at 4000 volts without
> shorting to ground
> because all the conduit is rusty and there is no ground
> cable. Meanwhile,
> the electrician trying to work on it thinks it is normal
> 440V, and fries his
> brains out because he shoulda been using a hotstick. Nobody
> likes corner
> grounded delta, but they are still around causing trouble.
> This nightmare
> schenario is why these things were owtlawed before I was born.
>
> --Lawrence
>
>
> ----- Original Message -----
> From: "Anthony Bussan" <
KILLspamTBUSSAKILLspam
WOODWARD.COM>
> To: <
RemoveMEPICLISTTakeThisOuT
MITVMA.MIT.EDU>
> Sent: Tuesday, June 18, 2002 1:56 PM
> Subject: Re: [EE]: Russia 380VAC three phase power Delta or Wye?
>
>
> > Wye doesn't have to have a center tap to neutral if the
> phases are loaded
> > correctly. With Delta, I don't know what you mean by
> "center tap of one
> > phase." And I definitely wouldn't connect any phase to
> neutral on delta
> > unless you like to see a lot of sparks. A direct
> connection to ground
> like
> > that will probably blow apart your whole fuse box and take
> you with it.
> >
> > Anyway have fun,
> > Tony
> >