[Asterisk-Users] UPS rating for SOHO asterisk box

[Daryl G. Jurbala]

> -----Original Message-----
> From: asterisk-users-bounces at lists.digium.com 
> [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of 
> Terry H. Gilsenan
> Sent: Wednesday, June 01, 2005 5:05 AM
> To: 'Asterisk Users Mailing List - Non-Commercial Discussion'
> Subject: RE: [Asterisk-Users] UPS rating for SOHO asterisk box
> 
> 
> I have many sites that have a 35amp Charger with 2 x 400ah 
> 900CCA deep cycle batteries (10 year warranty), and 1000VA inverters.
> 
> The combination makes for perfect power and about 2.5 days 
> run time with my network kit whish consists of several Dlink 
> wifi access points, 1 xbox (hacked into a router/firewall) 
> and a vsat system.
> 
> Total cost for the power kit AUD$1400 all up, and not a 
> single second of downtime in over a year.
[...]

Yep....you can (somewhat) build your own UPS with peoperly rated
equipment.  As a matter of fact, most telco installations don't have
"monolithic" UPS's (like you'll see in most larger datacenters....you
know..the big box that says Liebert on it), they use racks of batteries
with separate charging circuits.  Most of the equipment runs directly
off of the battery voltage, but you will find places with some inverters
as well.  Of course, the room is properly designed (spaced,
non-combustible racks, fire detection and supression systems, etc.) and,
in most jurisdictions they also have to carry one or more operational
permits (current Internation Fire Code requires permitting for stationar
lead-acid battery systems exceeding 50 gallons liquid capacity). 

> On the flipside, I have seen a ups flare when the transformer 
> overheated and melted the varnish, nasty!

I've seen completely unmodified (although not properly maintained) UPSes
as large as 5000 Va completely melt down to the point where they
destroyed their own chassis, damaged the rack they were sitting in, and
activated the clean-agent supression system in the rooms they were in.
This was actually a big problem with one of my customers....they hadn't
been maintaining their UPSes....the "replace battery" lights had been
lit for months (they had all been purchased at about the same time).
Within a span of about 3 months, 4 of them melted down similarly.  A
quick call to APC revealed that the batteries in these units were rated
for about 12 monts less than they had actually been in service, and a
simple battery replacement would have prevented the problem (the chassis
was rated for something like 3 sets of batteries...whatever the lifespan
of the batteries was....3 years I believe).

So, don't do stupid things with high voltage, like modifying equipment
that wasn't meant to be modified, using undersized equipment, failing to
properly vent batteries, or storing your contraption on or near
combustibles.  It's just NOT worth the risk.  Take it from someone who's
pulled his share of bodies (of both the live and dead varities) out of
buildings.  I've seen way too many fires started by electrical system or
device "modifications" similar to those described in previous posts.
And most people who do things like this just never consider the life
safety risk involved until its way too late.

I'll get off my soap-box now and get back on topic.

Daryl