Re: 240 vac variac observation

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

Original poster: "Allanh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <allanh-at-starband-dot-net>

You can run two varics back to back and they will work
fine but the fact remains that on standard house wiring the
two phases are out of phase, 120 on leg and 120 on the other ( reference to
gnd. and neutral) and 240 across the
two phases. They are 180 degrees out of phase. If you have an oscilloscope,
put one lead on one phase and the
other lead on the second phase, you will see two sin waves 180 degrees out
of phase. I live in Georgia also,
where in Ga. do you live?

allan

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, February 07, 2002 11:06 AM
Subject: Re: 240 vac variac observation


> 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
>
> _
>
>