In article ,
wrote:
Ok, not strictly D-I-Y i know, but I have been asked to come up with
some specs so that we can get quotes for a new power supply for our
server room at work.

W have 3 tall racks (30U from memory) round about 6 - 7 feet anyway
which are mostly stuffed full of Dell servers. These are rated at 2
Amp (The 1U jobbies) and 5A (2U jobbies). I don't know if this is the
maximum they draw at start up, or if they may take more at startup.
What I do know is that the 30A breaker which feeds the radial circuit
they all go back to (via a few UPSs) trips out if the power comes back
on after an outage

We have 50 odd racks in our machine room - and often had this problem.

The Dell servers were by far the worst culprits along with the EVA storage.
Sun and HP servers tend to be better. We have dual psu machine feed from
two independant distribution networks and most Dell boxes appeared to
run from one or other psu on not share the load between them. This tended to
cause one side of the rack to be overloaded and cause the breakers to pop :-(

Sorted by fitting different MCBs in the SAN racks and decent sequencing
power distribution to the server racks. We use APC power dist (I think
the models we have are http://www.apc.com/products/family/index.cfm?id=136 )
which give us remote (ssh or https) control of the outlets and also
sequencing (can be configured with timings to allow things to boot in
order). They also offer some load monitoring.

The ones we have are zero U models that fit nicely into our APC racks - you
might be better with a few of the rack mount versions if you don't have
room to mount them.

Not cheap, but pretty solid

Darren (oh, we stopped buying Dell servers as well )