Re: 240 vac variac observation

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

Original poster: "Yurtle Turtle by way of Terry Fritz <twftesla-at-qwest-dot-net>" <yurtle_t-at-yahoo-dot-com>

Not with my variac. As I stated, here in Georgia,
neutral = ground. To vary both phases would require 2
brushes. Mine is exactly as stated. I did however, run
two 120 volt variacs back to back, which did as you
stated.

--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "Allanh by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <allanh-at-starband-dot-net>
> 
> If you are speaking of normal house wiring, you
> drawing
> of the 240AC is wrong. A 240 variac varies each
> phase of the line voltage in
> reference to nutral. That means 120
> volts AC on each side of nutral 180 degrees out of
> phase.
> 
> allan
> 
> 
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Wednesday, February 06, 2002 6:43 AM
> Subject: 240 vac variac observation
> 
> 
> > Original poster: "Yurtle Turtle by way of Terry
> Fritz
> <twftesla-at-qwest-dot-net>" <yurtle_t-at-yahoo-dot-com>
> >
> > I'm probably stating the obvious to most of you
> guys,
> > but this is something I recently discovered,
> regarding
> > > 120 volt variacs.
> >
> > In my neck of the woods, neutral = ground.
> >
> > With a 120 volt variac, we are varying the output
> > potential relative to neutral. No problem. See
> below:
> >
> > --------)
> >         )
> >         )<------  0 - 120 vac
> >         )
> > 120 vac )
> >         )
> >         )
> >         )
> > --------)--------  common
> >
> > -----------------  ground
> >
> >
> >
> > In a 240 volt variac setup, we are varying the
> > potential relative to one phase, from 0 to 240
> volts.
> > This results in an unsymmetric 0 - 240 volts
> relative
> > to neutral/ground. See below
> >
> >
> > --------)
> >         )
> >         )<------  0 - 240 vac
> >         )
> > 240 vac )
> >         )
> >         )
> >         )
> > --------)--------  common
> >
> > ------------------ ground
> >
> > For example, I have a 34 kV DC PSU which wants 208
> > vac. If I feed it from my big variac, one leg will
> be
> > at a higher potential relative to neutral/ground,
> than
> > the other.
> >
> > Perhaps that's not a problem, but it might be for
> > some.
> >
> > Adam
> >
> > =====
> > Adam Minchey
> > yurtle_t-at-yahoo-dot-com
> > http://www.geocities-dot-com/yurtle_t/index.htm
> >
> > __________________________________________________
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> >
> >
> 
> 
> 


=====
Adam Minchey
yurtle_t-at-yahoo-dot-com
http://www.geocities-dot-com/yurtle_t/index.htm

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