"Michael A. Terrell" wrote:

"Pete C." wrote:

The no land line option is becoming very viable not that some cell
carriers are offering flat rate US plans, i.e. no minutes, no long
distance and no extra charges to and US number, land, cell or other.

As for the backup power for a fiber home terminal unit, any internal
battery it may have should only be a secondary backup. You need to have
your own "real" UPS covering that unit as well as your computer(s),
routers, aquarium, etc. all backed by a generator with an adequate fuel
supply.

My dad and step mom had a propane powered backup system installed
last year. They spent $20,000 by the time the work was done, and the
tank was filled. SO, my lights go out, and I hear their generator
running, while I'm busy shutting things down to conserve the UPS
batteries.

Not knowing the details I can't comment on why it cost $20k, but it can
certainly be done in most cases for a lot less, like around $5 max. That
won't get you a unit big enough to run every single thing in the house
typically, but if you select your emergency circuits well it will be
close enough for any normal outage.

On Fri, 21 Mar 2008 23:24:48 -0400, "Shawn" <shawn_75ATcomcastDOTnet
wrote:
"Bruce L. Bergman" <blnospambergman@earthlink.invalid> wrote in message
news:u0k7u3192h4qg500hr70ncvf7aq0c1rih0@4ax.com...

The GTE Splicer trucks and vans all carried a large (200CF range)
Nitrogen cylinder horizontally for air tools and cable pressurization,
you would chain the bottle to the pole if you needed to leave it in
the field. (And I suppose they still do since the work remains the
same, though the racks may have been upgraded.)

snip
--<< Bruce >>--

Bruce,

I often see bottles strapped to poles after some work has been done on a
splice (I assume). What is the nitrogen used for after they are complete?
Sometimes I have seen the bottles left for over a week.

Shawn

Depends - sometimes you are doing work in the middle of a cable run,
and they suspect a leak in an underground cable at the far end of the
run - and if there's a manhole at the other end that is full of water
where the leak might be, when the air pressure goes away the cable
could end up full of water...

It's bad enough on the newer plastic insulated cable because it can
be dried out, but with older paper insulated cables you get any free
water inside and any cable that got damp is trash - and that little
leak quickly becomes a major 1200 to 4200-customer outage disaster...

They'll put air on at the far end, past where you opened the cable
to work. That way the leak you cause with the splice case open
doesn't depressurize all the cable past you - now it's feeding from
the bottle back toward you and leaking from both ends at the case
you've opened. Meaning it still has the full 10 PSI on the cable
toward the CO and the far end, except for about 1 case either way and
1/8 mile that will see a reduction.

If the bottle is only left there a few days, it's because they're
working on that run. If it's there semi-permanently, the pressure man
(person...) in your area is either overworked or lazy, and there's a
persistent leak he hasn't found and fixed.

They feed air on all cables from the switchroom, with a compressor
and air dryer, and they have pressure transducers at the far ends to
monitor the pressure - you have to call in and tell the office you are
working on that cable, or they'll get an alarm and send the pressure
man out to find the trouble.

If you are in a rural area with really long cables, they run more
bottles just because of pressure drop and latency several miles form
the switchroom. If there is a need for one, they will stick a
pedestal mounted electric compressor and air dryer in the field, and
feed several cables from the far end.

Oh, and the power company also has some air-core cables deployed,
but they usually do theirs differently so you can tell. The L.A. DWP
hangs their Nitrogen bottles off the pole in a chain sling about 10
feet up, keeps the kiddies from playing with them.

Their bottles are often there semi-permanently, for example to
pressurize a little chunk of air-core underground cable where the 10KV
to 35KV feeder line changes from aerial to go under the freeway, then
back to aerial on the other side. If that cable (or cables plural)
isn't being fed air from a distribution station compressor, they need
a bottle on it. Wet power cables go BOOOOM!!

--<< Bruce >>--

On Sat, 22 Mar 2008 06:49:38 -0700 (PDT), stans4@prolynx.com wrote:
On Mar 21, 9:24 pm, "Shawn" <shawn_75ATcomcastDOTnet> wrote:
"Bruce L. Bergman" <blnospamberg...@earthlink.invalid> wrote...

There's still a lot of air-core cable out there, but it's all
underground trunk cables where they can control it. "If it ain't
broke don't fix it" still applies. Mostly Stalpeth jacket PIC cable
now, but there'll probably be some lead sheath paper or pulp insulated
out there for another 50 years or till it starts going bad.