UPS Recommendations: was Re: Power supply recommendations

[David Bandel]

On Tue, 23 Nov 2004 12:50:29 -0500, Leon Goldstein
<metapsych at earthlink.net> wrote:
> David Bandel wrote inter alia:
> 
> >Unfortunately, I see the same trend in UPSs.  The dampeners and
> >regulators (power supply geeks might call them zener diodes, etc., but
> >to most of us they're just filter components) have also been removed
> >from UPSs making them little more than batteries.  And while batteries
> >(which are really just big capacitors) dampen surges somewhat, as do
> >isolation transformers, etc., the new battery USPs aren't running off
> >the batteries all the time so the big dampeners are effectively not in
> >the circuit at the most critical times.
> >
> >That's how you make cheap power supplies and UPSs.  By removing
> >"unnecessary" components.  Funny how those components were necessary
> >when the supply was originally designed, but now aren't.
> >
> Any recommendations or preferences from among the currently available
> UPS offerings?

Personally, I stick to the APC SmartUPS series, although I believe the
APC BackUPS are similar, just don't have all the functionality.

The important things I look for when buying a UPS is surge protection,
especially clamping time.  This is the amount of time it takes for the
circuitry to recognize a rising voltage and "clamp" it.  A direct
lightning strike will go through anything, but the more protection you
have, the better.

UPS's that are constant battery (where you're running off the battery
all the time, not just switched over) are better because the batteries
are huge capacitors and will help dampen spikes.

Also, most houses in the US have good grounds, but it's important to
check from time to time.  Your house ground should be as close to 0
ohms as possible, but definitely not more than 10 (the phone/electric
companies usually say 20, but that's way too high).  Make sure all
your systems are well grounded to the electrical ground.

In my radio shack, I have 3 grounds (electrical and RF), an isolation
transformer, APC SmartUPS on the computers, and I strap everything
with not less than 3" wide copper straps.  This is overkill for homes
with computers, but I have several antennas, one a loop skywire 53
feet in the air with no trees for over 500 meters (real lighting rods,
but all well grounded). The steel poles I use are higher than my
verticals, so they don't usually see direct strikes, but I'm prepared
anyway.

Ciao,

David A. Bandel
-- 
Focus on the dream, not the competition.
            - Nemesis Air Racing Team motto