[rescue] argh, what did I do? (Onyx)

vance at neurotica.com vance at neurotica.com
Wed Jan 15 14:34:15 CST 2003

On Wed, 15 Jan 2003, Jochen Kunz wrote:

> > The only exception I can think of is perhaps (BIG) old VAXen.
> Hmm. Isn't there a VAX that uses three phase motors for the blowers?
> Thinking of that big CDC Cyber supercomputer I saw at the VCFe that is
> driven by a motor-generator as it needs 400 Hz AC. The motor-generator
> can convert 80 kW...

Is it the 11/780?

> > (However, someone did rewire a VAX6k to singlephase 230V I think)
> Yes, that is possible. The VAX 6k has a 320 V DC power rail that is feed
> from a three phase rectifier. This makes a rather smooth DC voltage from
> AC even without smothing capacitors. The actual PSUs are feed from this
> DC rail. It is easy to rewire the machine to work with 230 V single
> phase. You loose the nice three phase rectifier factor, but it still
> works. AFAIK you have to do a litle bit to fool the AC-OK detection.

I just fed split-phase to two of the lives (and neutral to the neutral) to
my DECsystem 5840, and it worked without any monkey-business.

Peace...  Sridhar

More information about the rescue mailing list