DC power versus AC power

Stephen Sprunk ssprunk at cisco.com
Mon Dec 30 03:09:06 UTC 2002


Thus spake "Scott Granados" <scott at wworks.net>
> 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.

2500-class devices only need 2A, but a GSR needs 60A -- and 60A DC is
significantly more dangerous than 60A AC due to the duty cycle.

If you _remember_ to defuse/disable the leads from the A _and_ B fuse panels
to the device you're working on, you'll be okay.  The real danger is when
people are working on the "upstream" side of the power panel, which is often
difficult/impossible to defuse and carries significantly higher amperages.

S




More information about the NANOG mailing list