On Mon, 13 Aug 2007 22:08:40 -0400, "Dana" wrote:


"w_tom" wrote in message
roups.com...
On Aug 13, 10:45 am, (Al Dykes) wrote:
Any name-brand UPS will have genuine surge protection. A power
strip
will have, at most, MOV chips that handle spikes and little else.

Cite manufacuture specs that claim that protection. You cannot.
Entire protection circuit in a plug-in UPS is the same circuit
inside
power strip protectors.

Keep on believing that crock. A UPS is way better than a power strip.


More embarrassing, a UPS protector circuit is often grossly
undersized even compared to power strips.

Again that is not even close to being true.
I have seen people try to place to many devices for a given UPS, but
that is
not what you are saying above

UPS is to protect data from blackouts and brownouts.

That can be one function, another more important function for other
people
is to keep the equipment running during blackouts and brownouts.



Once saved to
disk, then data needs no such protection. How robust is protection
inside computers? So robust that some of the dirtiest electricity
-
from a UPS in battery backup mode

Unless you have a very cheap UPS, most power from a UPS during
battery
operation is quite clean.





Everyone should get this point straight. All UPS's are not the same
and depending upon the power quality requirements of the IT equipment
and how long it must be kept running following the mains outage, will
determine the proper solution to his situation. If he has poor quality
mains power then either a power conditioner or a double conversion UPS
will be mandatory. A line interactive backup UPS, especially a stepped
sine converter type, will be no use at all.

A standard line interactive backup ups which most of us small time
users might buy for out PC does NOT clean up the incoming mains power
any more than a surge protector (either whole house or a power board
type).

The load, whatever it is, will run on normal mains power while it is
present. When mains power fails switchover to battery power occurs and
the load will now run from the DC-AC converter output for as long as
the battery can handle it. The small units will only keep the load
running for around 5 - 10 minutes on full load. This gives you time to
shut down all the computers to save work which is being performed at
the time until mains power returns. The quality output power from the
converter will depend on the quality and type of converter. A pseudo
sine wave or stepped sinewave converter can produce more noise than
you might find on the normal mains supply due to the odd harmonics in
the stepped sine output, so if noise is a problem for the IT equipment
being supplied this may not be the way to go. The next step is a
double conversion UPS.

A double conversion UPS does clean up the power provided that it
employs true sine wave conversion rather than stepped sine conversion.
The load is always running from the coverter but, the length of time
the load can continue to run when mains power fails is dependant upon
battery capacity. If the outage is more than a few minutes then the IT
equipment must be shut down. These units cost a lot more than the
normal line interactive UPS.