VAX 6000 3-phase conversion (was: Re: Three Phase)

From: Robert F Schaefer <rschaefe_at_gcfn.org>
Date: Sun Apr 22 05:54:52 2001

On Sun, 22 Apr 2001, Gunther Schadow wrote:

> Robert, you are awesome! I would very much appreciate if you took
> some pictures. I did some more experiment today and had quite strange

thanks... ;) I'll grab the camera again today. The reason why you didn't
find any power at the output is that the PS is switched by a controller
(the `Power & Logic Box' I believe) external to it. There is a contactor
(relay) inside, it its the last black box the three-phase power wires go
thru before they come to the round connector. (or first after the
connector, depending on which way you go... :) This may be manually
operated by pushing down on the armature. WITH THE POWER OFF, look at it.
 Either on the top, or the upper side, there will be a piece of plastic
that can be pushsed down towards the bottom of the contactor. You should
be able to measure continuity directly across from one color to the same
color with this pushed in, and open with it released. It may not be
possible to get all four contacts to close by pushing on it on the side,
so measure across all phases & the netural. You could also do this with
the PS energised, and look for voltage on the output, but this way is much
safer... (if I did it hot, I'd test at the end of the cable that connects
it to the `power & logic box'-- easier to find the right connection!)


>
> > The cable that connects the round
> > connector to the `power & logic box' has only six wires, two from each
> > phase. There are a number of other connections available on the round
> > connector, which leads me to believe it's a standard part for anumber of
> > different power schemes.
>
> >From the inside it looks as if each lead goes to at least two of those
> pins. This would seem reasonable as the pins themselves look pretty
> small for 800 W full power ...

Yup. Parallel runs for more current capacity.

>
> > Here's the fun part! Inside the `power & logic box', all three phases (
> > I'll be making a cable to replace the factory assembly, and rewireing the
> > distribution box to single phase, I believe. It should be 100% reversable.
>
> My plan is to buy a receptacle box for the original power plug and
> wire that box near my extra circuit-breaker box in the laundry /
> computer room in the basement. Given that the stange behavior of the
> power control lights are explained and my mistake in measuring the
> round connector's voltage output is discovered, is there anything to
> rewire inside the AC power box?

I would hazard a guess that they are trying to tell you that the
controller isn't plugged in to it, and it doesn't know what to do without
it, or perhps they're power OK leds for the three phase feed. IDK-- yet.

>
> I wonder, are we the first ones to fire up their 6000 in their private
> dwellings? BTW: has anyone noticed major interference with radios or
> TVs (the label on the machine talks about it ...)

It'll be a week or more before I crank her over-- I have some more
pressing projects I'm in the middle of.

If there is a lot of interference coming out of it, the thing must be a
microwave oven inside-- there's more shielding in that case than I've ever
seen before. Put a cup of water in the bottom, boot it and shut down, and
see how hot it is!

>
> regards
> -Gunther

Bob
Received on Sun Apr 22 2001 - 05:54:52 BST