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 Introduction
Power quality is worse
than ever. Problems such as blackouts, brownouts, surges and noise
are happening with increased frequency. According to a study
conducted by Bell Labs blackouts have increased by 150% since
1972. IBM says that a typical computer is subjected to more than
120 power problems per month. There is little that power companies
can do to minimize the risk because the power is subjected to
numerous outside influences as it travels to the customer sites.
The effects from power
problems range from subtle keyboard lock-ups and minor system
crashes-to the dramatic-complete data loss or permanent hardware
damage. Most of these problems can be avoided with the use of a
quality UPS.
* Determining Power
Problems
Problems such as
blackouts are easily indentifiable, but other problems are often
difficult to diagnose. The following symptoms may suggest that you
have been experiencing power problems:
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1. |
Your computer
re-boots for no apparent reason. |
|
2. |
Your computer locks-up for no apparent
reason. |
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3. |
Data files have been lost or corrupted
for no apparent reason. |
|
4. |
Your CMOS setup has been forgotten for
no apparent reason. |
|
5. |
You receive occasional error codes when
reading files. |
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6. |
Hardware including power supplies, or
logic cards has failed. |
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7. |
The image on your CRT appears to change
size or has other distortion. |
OPTI-UPS
An OPTI-UPS is an
advanced uninterruptible power system (UPS) consisting of a
battery source, a converter, and control equipment. It is designed
to prevent spikes, surges, sags, transients and blackout from
reaching your equipment. When AC power is present, the UPS filters
small fluctuations continuously. When AC power fails, the unit
employs its internal maintenance-free battery to supply back-up
power without interruption.
Type
of UPS
There are actually many
different types of UPS systems, some of which cannot be
categorized into either the standby or on-line types. Almost any
UPS fits into one of the following 3 categories:
Standby UPS(Offline) ?The AC line is the primary power
source. The battery/inverter circuitry supplies the load in case
of a power failure for fluctuation. Any drop in the voltage or
current is detected by the UPS, which automatically switches the
battery into the circuit, cutting of the main power line-thus
allowing the battery to supply the required power. The transfer
time should not take more than 4 milliseconds, as this is the
tolerance limit of a typical computer power unit.
On-line UPS ?This UPS operates with the inverter as
the primary power source supplying the load and therefore there is
no transfer time in case of power failure. This type of ‘on-line?
power eliminates any interruptions in the flow of electricity. And
since it uses more electronic wizardry than offline UPS, it is
priced higher. Besides the high price, on-line UPS also have the
disadvantage of high running costs and temperature. Since the
battery acts as the primary power source to the system, an on-line
UPS battery charger has to be powerful enough to generate enough
power to compensate for the battery’s power drain. This conversion
from AC mains to DC for the battery and back to AC through the
inverter results in a 25-to 30-percent power loss. The heat
generated as a consequence of the power loss shortens the life of
electrical components and reduces battery life.
Line-Interactive UPS ?This is the topology used by the
OPTI-UPS ES & PS series. The AC line power is the primary source
and is being constantly filtered. In case of a brownout condition
the automatic voltage regulation circuitry is activated to correct
the problem. The battery and inverter circuitry supplies the
backup power in case of a blackout.
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