Re(2): [SunRescue] Diff SCSI h/w

[James Lockwood]

On Mon, 20 Sep 1999, Tim Hauber wrote:

> OK, help.  It has been said on this list by a couple people that the
> pieces in my 690 MP chassis will run on 120V AC.  The various
> powersupplies (including on of these drive drawers, with 18G of Wide Diff
> SCSI drives in it) all are labeled 220V, there are no switches to manually
> select 120, and the ranges printed on them specifically say 208-230 V or
> similar.  It has been said that they are universal powersupplies
> restickered by Sun, but there is no visible indication of this.  Does
> anybody know where I can get actual documentation on Sun Chassis pieces
> (either hard copy or online)  I am reluctant to attempt to fire up a
> switching Power Supply on half voltage, for fear of damaging the supply,
> or the stuff on the other side of it.  

Check the stickers on top of the drive trays, there should be one labeled
"Power Supply".  Rev -03 supplies are known to work on 120V, -05 will not.
If you pull the top metal cover off and look at the sticker on the supply
(sometimes hard to see as it's on the side) then it will either say
100-240V or 200-240V.  All of them say 200-240V on the back, but that is a
Sun sticker and not a Zytec sticker.

Running a switcher on half-voltage will not hurt it if done for brief
periods (it will do no more damage than, say, a half-voltage brownout).
Make sure that it is hooked up (to the fans at least) to provide some
load.  If all you get is clicking every second or so, it needs more
voltage.

Most x90 chassis should run off of 120V.  This may also depend on p/s
revision, though.

Data from the FE handbook will not help, Sun claims that the supplies
are 240V-only even when they are not according to the manufacturer.

The best solution of all is to wire your computer area with 240V.  You
lose less to resistive and p/s losses this way.  A pity you have to pay
commercial rates in most areas to get a 3-phase feed.

-James