----- Original Message ----- From: "Scott Granados" <scott@wworks.net> To: <wb8foz@nrk.com>; "nanog list" <nanog@merit.edu> 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" <wb8foz@nrk.com> To: "nanog list" <nanog@merit.edu> 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....
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