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

From: Robert F Schaefer <rschaefe_at_gcfn.org>
Date: Sat Apr 21 06:27:43 2001

On Sat, 21 Apr 2001, Gunther Schadow wrote:

> Hi again,
>
> Thanks for those who commented on this power issue.
>
> This evening, I have given it a shot using my spare parts. I took
> the box that has the thick 3-phase cable. I opened the rear of that box
> and removed this cable in order to attach one that I can actually
> plug in somewhere. This is what I saw:
>

Last night, I open the lower power-supply box on my 6310, the one with the
power cable going into it, and the tee-handle power switch on the side,
(H405-E rev F07, FWIW). From what I could see, the three-phase power
enters via the cable assembly (DEC part number 17-01806-01) and gos
directly into a large, sealed, power filter. From there, it goes to the
main disconnect switch operated by the tee-handle, them thru a contactor
(three pole relay), then exiting via the round 19-position connector. In
short, it's still three phase when it comes out of this box. Further
complications exist; the various power recpticles on the rear and front
are tapped off of different phases inside, presumably in an attempt to
balance the draw on the three phases. Also, there is what appears to be a
small low-voltage supply inside it, as well as another small circuit board
that I didn't examine very closely.

Since the power is switched thru a contactor, there must be controller of
some sort that manages the startup of the VAX. I'll go out on a limb and
say it is in the `Power & Logic Box' (H-7206A). ;)

BINGO! Folks, we may have a winner in the power & logic box. I'll give
it a closer look some time today, but it sure looks good from here.
156~229 input voltage, and it has a `300 volt' LED on the front. Also,
there's ehough logic to control a few contactors.

>
> any thoughts appreciated,
> -Gunther

Bob
Received on Sat Apr 21 2001 - 06:27:43 BST