Re: Central Office Emergency Power [WAS Re: [PLUG] Re: FIOS]

["William H. Magill" <magill@mcgillsociety.org>]

On 01 May, 2006, at 10:38, TuskenTower wrote:
> While reading articles about emergency recovery (after Hurican
> Katrina), I came across some interesting information about the power
> capacity of the local central offices that serve telephone lines.  
> Central offices are equipped with battery backups and (maybe) backup
> generators.  During an emergency, without power these COs can last for
> a some days (I'm hoping some is more than 7 days).
>
> Maybe we should be asking for FIOS _and_ POTS (plain old telephone  
> service).

I don't know exact numbers these days for ALL CO's, however primary  
switching centers
maintained a full set of batteries and standby-generators with 7 day  
fuel supply on site and 15-30 day supply within a 6 hour delivery  
distance.
[Historically they were 9th and race and 24th and South, but I also  
know that Evergreen (38th and Chestnut) is similarly equipped now.]

The classic POTS system carries 48v DC on the lines - virtually all  
the time. There is, or at least there was, a special number one could  
dial which would allow tapping the battery directly, used routinely  
by field linemen back in the days of Ma Bell for powering soldering  
irons while up on a pole! This 48 volt current is supplied by the  
batteries "in the basement." They are on-line all the time, under  
constant "trickle charge" -- basically a submarine system. In the  
event of a mains outage, a stand-by generator would kick-in and spin  
up within 15 minutes to keep the charge up. (We're talking about a  
stand-by generator here the size of a 40 foot trailer.) Historically,  
9th and race simply would pull the plug on the Mains once a month and  
run on the Stand-by system for a 4-12 hour period as part of  
"standard operating procedures."

How those systems have evolved over the past 25 years is hard to say.  
Minimally, if one takes Evergereen as an example, the power  
requirements went from powering equipment spread out over 6 floors to  
powering equipment on less than one floor. So, theoretically, the  
generator and tanks they have installed there will last a LOT longer  
than in the past. (Note that the Verizon Mobile operation at 40th and  
Chestnut has a completely separate stand-by generator capacity.)

The real question about Fibre based systems is how is the equipment  
"in the loop" powered. Any kind of repeater, switch or similar device  
in the loop outside the CO needs to be powered.

I know that one can buy 48v DC powered gear from Cisco and other  
vendors. DEC used to sell a 48v powered Alpha (the 1000) which only  
just last year (2005) went off the  "able to purchase replacement  
units" list from HP.

One interesting question about FIOS would be -- how does it (if it  
does) qualify for "life-line" service? "Life-line" service is a  
specific tariff with the PUC available to elderly, disabled and  
similarly defined individuals. I don't know the specifics of the  
tariff, and it may be only a "low-cost," not "level of service"  
definition.

T.T.F.N.
William H. Magill
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magill@mcgillsociety.org
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