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RE: DATACENTER: DC Power
Short answer, 120VAC can kill you deader than last Christmas. 48VDC can
not, rather, there are fewer condition under which it can. When you have
hundreds of boxen, in multiple racks, you have a farly complex power
wiring harness. Should this harness get shorted to someplace unexpected
and you get hold of it, you would rather it be DC, vs AC, I guarantee
it.
The other legacy reason is that, in the old telco COs,.48VDC was
directly available from the battery pack, without interveneing
electronix. It made for a real simple KISS and bullet-proof system.
Remember, the entire phone system was driven from the battery pack at
the CO, including the CPE.
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Paul Bruff
> Sent: Friday, June 25, 1999 3:43 PM
> To: [email protected]
> Subject: DATACENTER: DC Power
>
>
> Hi All,
>
> I would appreciate it is someone could tell me what the
> pereived benefits of
> using
> DC power over AC are?
>
> We are completely AC, which is also smoothed by our UPS
> system, giving a
> clean
> supply. We have customers asking for DC power, and we can't
> get a definitive
> answer to why DC is required. All I have is a throwaway
> quoute that "DC is
> safer
> to work on whilst live" (surely that only applies to work on
> the PSU?). I
> must also say that I
> am also only just really learning about power systems etc,
> having come from
> a software
> background and now runnning a datacenter I am learning all
> the time (and
> enjoying it too :-) )
> hence simple explanations, pointers to resources for the
> layman, good books
> on power, aircon
> etc would also be much appreciated.
>
> Many Thanks,
> Paul.
>