Mini & Mainframe Power Requirements

From: Don Maslin <>
Date: Mon Jan 19 13:29:00 1998

On Mon, 19 Jan 1998, William Donzelli wrote:

> > One scheme that I have seen used to power a 3-phase motor (on a lathe or
> > such) is to connect a 3-phase motor of comparable rating or higher to the
> > single-phase mains and also connect all three phases to the motor to be
> > powered. The motor connected to mains is powered up - it may require a
> > twist to get it spinning - and when up to a steady speed, the lathe (or
> > whatever) motor may be powered up. I'm sure that there are some
> > inefficiencies, but I have seen it work.
> Yes, it works, but is quite inefficient. I would venture to say that using
> a real motor-generator would be better, if properly maintained.

Can't quarrel with that, but the price difference between an old 3-phase
induction motor and an MG set can be rather impressive!

                                                 - don

> Motor-generators are not as bad as most people think - a good one is
> fairly efficient, provides isolation and regulation, and can take a lot of
> electrical abuse. They are just bears to move (done it - not fun).
> William Donzelli
    Don Maslin - Keeper of the Dina-SIG CP/M System Disk Archives
         Chairman, Dina-SIG of the San Diego Computer Society
       Clinging tenaciously to the trailing edge of technology.
         Sysop - Elephant's Graveyard (CP/M) - 619-454-8412
        see old system support at
Received on Mon Jan 19 1998 - 13:29:00 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:30:57 BST