RE: [TCML] homebrew VFD?

[William Noble <william_b_noble@xxxxxxx>]

according to my web page, they are:

Allen Bradley Cat 22A-D2P3N104 controllers input is 3 phase 342 to 538 V (i.e., 440V), .75KW

see photo here http://www.wbnoble.com/forsale/controllers_dc_ac_tach_etc.htm

 

I seem to remember that they don't monitor for 3 phase on the inputs, but I am at work and can't look that up for you right now.

 

 


 
> Date: Tue, 11 May 2010 03:10:55 -0700
> From: yurtle_t@xxxxxxxxx
> Subject: RE: [TCML] homebrew VFD?
> To: tesla@xxxxxxxxxx
> 
> Are your VFDs 440 single phase to 440 three phase? If not, it would take a typical hobbyist more than a simply step up transformer to use them.
> 
> --- On Mon, 5/10/10, William Noble <william_b_noble@xxxxxxx> wrote:
> 
> > From: William Noble <william_b_noble@xxxxxxx>
> > Subject: RE: [TCML] homebrew VFD?
> > To: "Tesla list" <tesla@xxxxxxxxxx>
> > Date: Monday, May 10, 2010, 4:55 PM
> > 
> > a VFD putting out a square wave will do really nasty things
> > to a motor or transformer - and you are working really hard
> > to do what you can buy cheaper - for example, I have some
> > small VFDs that are 440V input, so they are hard to sell to
> > a home hobby person - I got them inadvertently - instead of
> > making a VFD, you could just step your 110 up to 440 and use
> > one of these things and get all the nice features of a VFD
> > such as torque control and full RPM from near zero to >
> > 60 hz (you can find the units on my web site,
> > wbnoble.com).  Small 3 phase motors are cheap, when you
> > get them used, and 440V ones are even cheaper so my
> > recommendation would be to use a true 3 phase motor and a
> > real VFD.
> > 
> > > Date: Mon, 10 May 2010 14:27:40 -0700
> > > From: yurtle_t@xxxxxxxxx
> > > Subject: Re: [TCML] homebrew VFD?
> > > To: tesla@xxxxxxxxxx
> > > 
> > > I assume you're trying to make a single phase VFD. I
> > ran a single phase motor from a 3 phase vfd by disabling
> > it's phase imbalance monitoring. It worked OK up to a point.
> > If I ran it too slow, the motor's internal centrifugal
> > switch started disengaging. I considered adjusting the
> > weights, so it would engage at a lower speed, but ended up
> > buying a 3 phase motor. My smaller sync motor doesn't have
> > this switch, so I'm sure it would have worked just fine.
> > > 
> > > Adam
> > > 
> > > --- On Mon, 5/10/10, Scott Bogard <sdbogard@xxxxxxxxx>
> > wrote:
> > > 
> > > > From: Scott Bogard <sdbogard@xxxxxxxxx>
> > > > Subject: [TCML] homebrew VFD?
> > > > To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> > > > Date: Monday, May 10, 2010, 1:34 PM
> > > > Greetings all,
> > > >      While my intentions with this
> > are
> > > > completely off topic, the information could be
> > extremely
> > > > helpful for those running asynchronous rotaries,
> > and I know
> > > > of nobody else to ask this question, thus I fell
> > no guilt
> > > > putting it here.  I want to know if it is
> > possible to
> > > > essentially build a variable frequency drive,
> > this is what I
> > > > had in mind.  Get a mot, remove the windings
> > then make
> > > > your own to take 36V to 120V.  Drive the
> > primary with a
> > > > variable flyback type inverter, designed for
> > 1-120 Hz. 
> > > > So we have a DC square wave entering the
> > primary.  On
> > > > the secondary put a capacitor sized to take a
> > square wave
> > > > and make it nearly sinusoidal (so perhaps a cap
> > resonate
> > > > with about 90 Hz?).  And then feed your
> > secondary into
> > > > your induction motor winding.  It seems to
> > make sense
> > > > in my head but it seems a bit too simple, perhaps
> > the square
> > > > wave will not really drive the mot core correctly
> > because of
> > > > saturation in which case I don't know what to
> > do.  Any
> > > > thoughts or should I just abandon this.
> > > > 
> > > > Scott Bogard.
> > > > _______________________________________________
> > > > Tesla mailing list
> > > > Tesla@xxxxxxxxxx
> > > > http://www.pupman.com/mailman/listinfo/tesla
> > > > 
> > > 
> > > 
> > > 
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> >         
> >           
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> 
> 
> 
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