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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: DC power versus AC power
----- Original Message ----- From: "Scott Granados" <[email protected]> To: <[email protected]>; "nanog list" <[email protected]> Sent: Sunday, December 29, 2002 3:40 PM Subject: Re: DC power versus AC power > > Is 48V DC at the amps present normallyin switch rooms etc enough to cause > electricucian? I have seen bad things with wrenches dropped across > batteries even 12 volt car batteries although in this case it was a large > battery bank in a submarine but I was curious about the 48V sources in > switch rooms. I've laid across the buss-bars before...definitely an uneasy feeling, but never felt it unless I was sweaty. <g> Capability of thousands of Amps, but it's the old "power transfer" deal...internal resistance of the source vs. internal resistance of the load (your body). --Michael > > > > ----- Original Message ----- > From: "David Lesher" <[email protected]> > To: "nanog list" <[email protected]> > Sent: Sunday, December 29, 2002 4:43 PM > Subject: Re: DC power versus AC power > > > > > > Unnamed Administration sources reported that Michael Painter said: > > > > > > > > > > > > > >But, as Stephen already eluded to... Compared with an AC plant > design, to > > > me, one of the biggest drawbacks of a DC plant is safety (I have had to > > > kick a fellow worker away from the rack before). << > > > > > > What was the worker doing? Is this 48 VDC? > > > > Bet so. > > > > And note, it's not just ISP's, of course. I heard that Sprint > > PCS ha[s,d] a Dallas tech in critical condition and a dead switch > > after a dropped wrench & resulting fire. > > > > In the words of Phil Esterhaus: > > > > Let's be careful out there.... > > > > > > > > > > > > -- > > A host is a host from coast to [email protected] > > & no one will talk to a host that's close........[v].(301) 56-LINUX > > Unless the host (that isn't close).........................pob 1433 > > is busy, hung or dead....................................20915-1433 > > >
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