[rescue] 3-phase power, was: argh, what did I do? (Onyx)

Dave McGuire mcguire at neurotica.com
Wed Jan 15 22:04:14 CST 2003

On Wednesday, January 15, 2003, at 03:34 PM, vance at neurotica.com wrote:
>> 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.

   Really?  I wonder if this approach would work with the VAX 7000.  It 
rectifies 3-phase AC to a 300V rail too, does it not?  I think I recall 
Bob Keys having said that on port-vax at one point.  Can anyone confirm?


Dave McGuire           "She's a cheek pincher.  I have scars."
St. Petersburg, FL                          -Gary Nichols

More information about the rescue mailing list