nanog mailing list archives
Re: DC power versus AC power
From: "Michael Painter" <tvhawaii () shaka com>
Date: Sun, 29 Dec 2002 15:37:24 -1000
----- 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 powerUnnamed Administration sources reported that Michael Painter said:But, as Stephen already eluded to... Compared with an AC plantdesign, tome, 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 coast.................wb8foz () nrk com & 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
Current thread:
- Re: DC power versus AC power, (continued)
- Re: DC power versus AC power Michael Painter (Dec 29)
- Re: DC power versus AC power David Lesher (Dec 29)
- Re: DC power versus AC power Scott Granados (Dec 29)
- Re: DC power versus AC power Charles Sprickman (Dec 29)
- Re: DC power versus AC power David Lesher (Dec 29)
- Re: DC power versus AC power Scott Granados (Dec 29)
- Re: DC power versus AC power Barney Wolff (Dec 29)
- Re: DC power versus AC power David Lesher (Dec 29)
- Re: DC power versus AC power David Diaz (Dec 29)
- Re: DC power versus AC power Scott Granados (Dec 29)
- Re: DC power versus AC power Michael Painter (Dec 29)
- Re: DC power versus AC power Michael Painter (Dec 29)
- Re: DC power versus AC power David Lesher (Dec 29)
- Re: DC power versus AC power David Lesher (Dec 29)
- Re: DC power versus AC power Owen DeLong (Dec 29)
- Re: DC power versus AC power Stephen Sprunk (Dec 29)
- Re: DC power versus AC power joe mcguckin (Dec 29)
- Re: DC power versus AC power Stephen Sprunk (Dec 30)
- Re: DC power versus AC power David Lesher (Dec 30)
- Re: DC power versus AC power Robert E. Seastrom (Dec 30)
- Re: DC power versus AC power Stephen Sprunk (Dec 30)