Subject: RE: 4000 200 BA213 power requirements and distribution info
To: , <>
From: Antonio Carlini <>
List: port-vax
Date: 05/14/2003 14:52:38
> moving externally into storageworks shelves.  Thus, the 
> internal power supplies will only be powering up the 
> cpu/ram/scsi cards, and maybe a cxy08 card.  Is that enough 
> load on the internal power supplies, or should I leave some 
> drives in there, too?

The BA213 has two PSUs, each of which powers half of the
Q-bus slots. I forget how the drive power is distributed
but I assume that's shared too.

If *either* PSU does not have enough load, it will 
switch off and the *whole* box fails to work. For
a small config such as yours, you won't have enough
(or indeed, anything!) to load the LH PSU, so the
box won't power up. There is a load board which
was shipped in such configurations - it was usually
placed in the leftmost slot, I guess. If you already
have one, you should be fine (it's easy to recognise
as it has plenty of resistors and nothing else on it).
If you don't have one, you may find the box won't come 
up at all.


Antonio Carlini