Looking for VAX6000 items

Paul Koning paulkoning at comcast.net
Wed Jul 14 15:05:51 CDT 2021



> On Jul 14, 2021, at 3:53 PM, Guy Sotomayor <ggs at shiresoft.com> wrote:
> 
> 
> On 7/14/21 9:50 AM, Paul Koning wrote:
>> 
>>> On Jul 14, 2021, at 12:33 PM, Guy Sotomayor via cctalk <cctalk at classiccmp.org> wrote:
>>> 
>>> I've found 2 issues w.r.t. "rotary converters".
>>> 
>>> * They *always* consume lots of power regardless of the actual load
>> Really?  That seems odd.  A rotary converter is merely a three phase motor with run capacitors.  Just like any other motor, its power demand depends on the applied load.  A normal motor spinning without anything connected to it consumes power to overcome electrical, magnetical, and friction losses, but none of these are particularly large.
>> 
>> Can you cite a source for this?
> Spec sheets for various rotary converters that I looked at.  I'd have to go back and find them again but they typically drew full load power all the time...and they were *loud*.

Odd.  I know "Phase-a-matic" which is sold by various machinery companies like MSC Direct.  Checking their brochure (at https://phaseconverters.phase-a-matic.com/item/rotary-converters/rotary-converter/rotary-converters#) shows -- for example -- the 3 hp converter idles at 3 amp.  That's 600 watts at the very most, probably less than that due to power factor but I don't see that discussed.

	paul



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