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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>
240 volts to common??? Where did that come from? We're
obviously having a communication breakdown. I give
up.
Adam Minchey, P.E. (credentials)
--- 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>
>
> In house wiring in the US there should NEVER be 240
> volts AC to common. I
> think you are using the two hot wires to feed your
> variac. Your drawing is
> not correct.
> If you do have 240 AC to common/neutral then you
> have
> a dangerous condition and it should be corrected
> immediately. I have been a
> licensed electrician and electrical engineer for
> over 40 years, what are
> your credenials?
> allan
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Thursday, February 07, 2002 9:00 PM
> 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>
> >
> > The use of CAPS is for emphasis, I'm not
> SCREAMING!
> >
> > You're missing my point. With two 120 volt variacs
> > back to back, there are TWO brushes. My 240 volt
> one
> > has ONE.
> >
> > I never stated anything about PHASING, I simply
> stated
> > that varying my 240 volt variac results in an
> output
> > of 0 to 240 volts, RELATIVE TO THE COMMON. And in
> > residential 240 volts usage, WITH MY VARIAC, the
> > common is one leg (excuse me for using the word
> > phase). This results in one output leg at a
> different
> > potential RELATIVE TO THE NEUTRAL than the other.
> You
> > don't need a scope to prove this, just look at my
> ugly
> > ascii diagram below and noodle it out. At any
> setting,
> > I get 120 volts differential between the common
> and
> > the ground. This MUST BE, if you look at how the
> thing
> > is wired up. I also confirmed this my my DMM. How
> else
> > could this thing be wired? Of course, this doesn't
> > matter when I use my pig, as I don't use the house
> > neutral/ground connection.
> >
> > --------)
> > )
> > )<------ 0 - 240 vac
> > )
> > 240 vac )
> > )
> > )
> > )
> > --------)-------- common
> >
> > ------------------ neutral/ground
> >
> >
> > Adam
> >
> >
> > --- 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>
> > >
> > > 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
> > > > > >
> > > > > >
> > > > > >
> > > > > > For example, I have a 34 kV DC PSU which
> wants
>
=== message truncated ===
=====
Adam Minchey
yurtle_t-at-yahoo-dot-com
http://www.geocities-dot-com/yurtle_t/index.htm
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