[ale] help providing stable power to pc's to ride through storms

[Bob Toxen]

On Mon, May 21, 2012 at 08:36:00PM -0400, Ron Frazier (ALE) wrote:
> Hi guys,

> I need some electrical power advice. It's possible you will give me
> the answer and I won't be able to afford it, but I'd like to know what
> you think.

> Counting my wife's machine, my computer table has 4 laptops, 1 desktop,
> 2 monitors, and miscellaneous hubs, speakers, phones, etc.
Short best recommendation: buy a 1000W or 1500W APC of TripLite UPS.
Leave it plugged in to the wall during storms.  Turn off the monitors
if the lights go out (except to shut down systems if the power stays
out for more than 5 minutes, in which case it will be out for a while).

I've had an excellent 17 years of experience with APC, including a storm
that fried other non-APC protected equipment (an electronically
controlled ceiling fan).  I know a few others have a bad opinion of APC
and recommend TripLite.  Don't even think of buying any other brand
than APC or TripLite.

The good brands are designed so that on a direct (or near) lightning hit
that circuits between the wall and your computers burn out, breaking the
path to your computers to protect the computers.  Realistically, a
direct hit is extremely unlikely and can fry even unconnected
electronics due to induced currents, arcing, and such.  (How many times
has your house been hit by lightning before?)

It's more critical to also run phone and cable lines (if you get cable
Internet) through a UPS/Surge Protector's filters.

If you really want to be protected against a direct lightning strike
(talking about a motor-generator setup), you first need to insure
several inches to a foot separation between any cables "outside" of the
UPS/Surge Protector filters, e.g., extension cords and anything being
protected to protect against an arc.

Consider lighting rods installed on your roof (maybe $2000-3000 or so)
if you're really worried.

My "Smart" APC 1500 (a year old) displays how many minutes it should
keep equipment running given current power usage.  Mine says 120 minutes
for 4 towers and a laptop and one monitor.


Remember that laptops use roughly 40-100W, hubs tiny amounts, blanked
monitors not too much, and towers (guessing) 200-500W for high-end ones.
Use an AC ammeter or wattmeter to measure for sure.  The running power
often is 25-50% of what the data plate claims as a maximum.


If you want even more protection, instead of a motor-generator, spend
$1000 for a Yamaha 2 KW generator (fairly quiet) or roughly $1500-2000 for
a Honda really quiet generator and switch the UPS plug to the generator
when it is storming.  I used a relay for an automatic switch but that
risks a lighting strike arcing across the relay's 0.1 inch contact gap.
I assume that the UPSs will work.

In any case, frequent OFF SITE backups are a must.

> Sincerely,
> 
> Ron

Bob Toxen
bob at verysecurelinux.com               [Please use for email to me]
http://www.verysecurelinux.com        [Network&Linux security consulting]
http://www.realworldlinuxsecurity.com [My book:"Real World Linux Security 2/e"]
Quality Linux & UNIX security and SysAdmin & software consulting since 1990.
Quality spam and virus filters.

"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond where
the shadows lie...and the Eye is everwatching"
-- The Silicon Valley Tarot Henrique Holschuh with ... Bob