Looking for an IBM 3803

[Patrick Finnegan]

The easiest thing to do is to pick up some cheap VFDs which will take 1ph
in and put out 3ph to run the blower motor.

Patrick Finnegan

On Wed, Sep 8, 2021, 11:34 Chuck Guzis via cctalk <cctalk at classiccmp.org>
wrote:

> As long as you don't need the full blower capacity, you can probably do
> the 3-phase-to-single-phase trick by using a capacitor from the third
> lead to either (which one will determine rotation direction) of the two
> other leads and feeding those leads with single-phase.   It's done very
> often here with 3-phase shop equipment acquired by residential
> hobbyists.  For motors, it's not critical, but it's not something that
> you'd want to do for electronics--the phase distortion rules that out.
>
> --Chuck
>
>
>
>
> On 9/7/21 11:31 PM, Curious Marc wrote:
> > Yes, we are hoping that we can power the  blower with 3 phase and the
> > rest directly from the 240V electric car circuit… Not sure if that can
> > be rewired for that.
> > Marc
> >
> >> On Sep 6, 2021, at 6:50 AM, Patrick Finnegan <pat at vax11.net> wrote:
> >>
> >> 
> >> On Mon, Sep 6, 2021, 06:36 Curious Marc via cctalk
> >> <cctalk at classiccmp.org <mailto:cctalk at classiccmp.org>> wrote:
> >>
> >>     I got both the 3420s and the 3808 from Sellam. On the restoration
> >>     docket, now with a better chance thanks to the ALDs which I
> >>     recently got from Gabriel himself. I scanned my 3420 ALDs and gave
> >>     them to Gabriel in return. Biggest annoyance, besides humongous
> >>     size and weight, is the amount of 3 phase power required.
> >>
> >>
> >> From what I remember, the only thing that requires 3 phase in the
> >> whole system is the blower motor in the 3420 drives. The rest are
> >> powered off of single phase 200-240VAC.
> >>
> >> The large 3 phase input on it 3803 is likely overkill for even a
> >> controller and full string of 8 drives. It's easier to oversize things
> >> and have a 3x safety margin, then deal with running close to the
> >> limits and risk any problems from poorly installed site wiring.
> >>
> >> Pat
> >>
> >>
>
>
> --
> --Chuck
>
> Sent from my digital computer
>
>