3-phase (was: Re: CDC 9766 Drive and packs)

From: John Amirault <amirault_at_epix.net>
Date: Wed Feb 3 22:41:21 1999

Hi,
Why not just go out and BUY a three phase converter? You know that such a
thing does exist now.

John Amirault

Philip.Belben_at_pgen.com wrote:

> > so don't get the idea that you can
> > run it in your house or garage.
>
> My parents have 3-phase electricity at home, but I don't (yet). But I
> think it's more common in the UK than in the US. (BTW my parents have a
> 16th century farmhouse which they heat electrically during the winter.
> Maximum load we've measured, 36kW.)
>
> I am told (I think it was Toy Duell first pointed it out to me) you can get
> reasonable 3-phase using a largeish induction motor (say a mechanical
> rating 2 or 3 times the electrical load you want to connect), without a
> mechanical load: wiring one phase to ground, a second to line, and the
> third to line through a capacitor for an approximate 60 degree phase shift.
> The induction motor will also act as a generator, and produce enough emf to
> tidy up the phase relationships and voltage imbalance. But be warned - you
> will not have the right voltage, and one of the phases (rather than the
> star point) will be at ground potential. A bank of three single-phase
> isolating transformers should do the trick if either of these is critical
> (a single autotransformer, upstream of the converter, will also work if
> only voltage is critical.)
>
> Also be warned. I am confident that this works _in theory_ but I have
> never tried it.
>
> Philip.
Received on Wed Feb 03 1999 - 22:41:21 GMT