[54409] in North American Network Operators' Group
Re: DC power versus AC power
daemon@ATHENA.MIT.EDU (Owen DeLong)
Sun Dec 29 22:10:50 2002
Date: Sun, 29 Dec 2002 19:09:50 -0800
From: Owen DeLong <owen@delong.com>
To: Scott Granados <scott@wworks.net>, wb8foz@nrk.com,
nanog list <nanog@merit.edu>
In-Reply-To: <000a01c2afa4$628b7840$6701a8c0@hqloaner>
Errors-To: owner-nanog-outgoing@merit.edu
Absolutely. Often, there are more than a few hundred amps available.
Remember, many of those switch rooms were built to specs to drive a very
large number of solenoids, relays, etc. All relatively high-current
devices compared to today's solid state stuff. Alot of the specs were
never reduced, the rooms just got bigger, and the number of customers.
There's a reason the backbone is multiple copper plates and not just
wire.
Owen
--On Sunday, December 29, 2002 5:40 PM -0800 Scott Granados
<scott@wworks.net> wrote:
>
> 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.
>
>
>
> ----- 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....
>>
>>
>>
>>
>>
>> --
>> 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
>>
>
