Re: [TCML] Variable RSG

["DC Cox" <resonance@xxxxxxxxxxxx>]

Bart

Have you had any problems with the VFD setup being affected by the RF or
magnetic fields under the primary coil, eg, in the base when the RSG is
placed?  Especially with DRSSTCs with their extremely high primary currents
and fast switching speeds producing large pulses in controller wires, etc.

Does anything kick back into your controller causing full speed lockon, or
do you use some filters of some type between the RSG motor and the
controller which is usually at a remote location?

Dr. Resonance






On Tue, Apr 8, 2008 at 8:07 PM, bartb <bartb@xxxxxxxxxxxxxxxx> wrote:

> Hi Scott,
>
> I meant to reply to your thoughts about Grainger, but deleted the email
> and emptied trash. So writing this under and new subject.
>
> Anyway, yes Grainger does have some decent prices. But, for AC speed
> control, price is HP dependent (even at Grainger). If motor is under 1/4HP,
> you can pick up a speed control for $34. But for something like a 1HP motor,
> you head to the $170 range minimum. I use a 2HP Baldor myself. This of
> course gets even more expensive for speed control. Even at 1HP, your already
> at VFD prices. The motors themselves are cheap and 3-phase is likely the
> least expensive. For DC motors, the price can get very high in the 1HP
> range. This is where eBay comes in real handy.
>
> Adam and myself are using a VFD to control a 3-phase motor and vary speed
> with a simple potentiometer. My Altivar31 2HP VFD is expensive at $300 each
> off the shelf. No matter how you slice it, as HP is increased, variable
> speed will cost a bundle between the motor + controller if purchased as new
> (even at Grainger). I think eBay is still probably the best way to beat
> these enormous prices.
>
> BTW, I should let everyone know I have a brand new (in box complete with
> 375 page manual) ABB 3HP VFD for sale which list in the $500 range. I'm
> letting it go for $200. P/N is ACS350-01E-09A8-2, 1-phase 200 to 240, 21A
> and 3-phase 230V out, 9.8A, 0 to 500 Hz variable frequency. I haven't used
> it and I don't know any of the details. Should not be too difficult to
> figure out.
>
> I also have a used 2HP SquareD Altivar 31 VFD for sale for $125. Works
> perfect! Don't have the p/n handy, but it's 1-phase 200-240 in and 3-phase
> 230V out with 0 to 500 Hz variable frequency.
>
> If anyone wants these, they should contact me at bartb@xxxxxxxxxxxxxxxxx I
> will also offer a money back guarantee that these VFD's are "both" in new
> working order. In order to use these VFDs, it is necessary to pick up a 2HP
> or 3PH 3-phase motor for them (as appropriate to the VFD HP rating). Check
> eBay. Sometimes these motors can be found for around $50. I have only one
> spare 1HP 3-phase motor on hand, but it doesn't match these particular
> VFD's. However, if you come across a VFD or speed controller requiring a
> 1HP, 3-phase motor, I will sell it to you for $50.
>
> BTW, for those that don't know, Leeson (major motor manufacturer) just
> announced  that they are off to Mexico to build their motors! Cheaper labor
> I guess.
>
> Take care,
> Bart
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