Another consideration is that this would effectively put 42 machines on the same 12v rail, and the same 5v and so on. So if a component in one machine failed in such a way that it shorted across that rail, it would take all devices on the rail down unless they each had individual load breakers for each rail. There's also a fairly good chance the short would happen during node insertion, so the breaker would need to be outside of the node, possibly ruling out the cheap bus-bar idea unless the breakers were inbetween the busbar and chasis.
On Dec 21, 2007 2:00 PM, Brian Kelsay [email protected] wrote:
Unless those DC rack supplies are ten times more expensive to replace and more likely to fail than a server power supply and harder to find.
On Dec 21, 2007 1:52 PM, Jonathan Hutchins <> wrote:
The point of all this is that instead of every piece of equipment having it's own switching power supply, with fan, you supply the required voltages to the whole rack from a common pair of fail over power supplies. Each box then gets it's own +12,+5, and -5 (or whatever), and we have one
less component per unit to fail.
Converting the power once then distributing it really does beat distributing the AC and converting it at each unit, there are savings in equipment cost, efficiency, and cooling.
Because of this, a 48 volt distribution system doesn't make as much sense, nor does it offer as much advantage over a 120/240V AC distribution system.
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