Looking for VAX6000 items (Paul Koning)

[Michael Thompson]

The power cord is three-phase, and actually daisy-chains to a second and
third drive. The phases on the AC output connector are rotated to balance
the load on all three phases when three drives are daisy-chained. If you
look at the power wiring diagram on page 3-120 of the Memorex 677-01 manual
you will see only two of the phases going to the power transformer.

On Thu, Jul 15, 2021 at 4:22 PM Paul Koning <paulkoning at comcast.net> wrote:

>
>
> > On Jul 15, 2021, at 4:19 PM, Michael Thompson via cctech <
> cctech at classiccmp.org> wrote:
> >
> >>
> >> From: Paul Koning <paulkoning at comcast.net>
> >> To: Chris Zach <cz at alembic.crystel.com>, "cctalk at classiccmp.org"
> >>        <cctalk at classiccmp.org>
> >> Subject: Re: Looking for VAX6000 items
> >>
> >> A number of the large disk drives use 3 phase motors; RP04/5/6 are
> >> examples as well.
> >>
> >> Three phase motors won't run on single phase power without help from run
> >> capacitors.  (There is no such thing as "two phase power" -- 220 volts
> is
> >> single phase, balanced.)
> >>
> >>        paul
> >>
> >
> > The RP06 uses 220VAC single phase motors for the spindle and blower.
>
> Interesting.  I distinctly remember a disk drive installation manual that
> warned about phase order.  Perhaps that was for the RP04 and not the RP05/6
> ?
>
>         paul
>
>

-- 
Michael Thompson