Most common sources of data loss (reported by APC
and Contingency Planning)
Power Failure/Surge: 45.3%
Act of Nature Damage: 21.6%
Fire or Explosion: 8.2%
Hardware/Software Error: 8.2%
Network Error: 6.8%
Human Error/Sabotage: 3.2%
Other 6.7%
Do I need to protect my computer?
A power back-up is a a great way to not loose data when a short
backup occurs, but it also protects against power problems that you never see, but which
can be detrimental to your system or network. Brown-outs, spikes, and line noise can be
just as bad or worse than a blackout for sensitive electronic equipment.
A study by IBM showed that a typical computer is subject to
more than 120 power problems per month. The effects of power problems range from small,
unnoticed glitches to complete data loss or damaged hardware.
Often the question of "To back up or not to back up" is a financial
one. What is the price of down time? Data loss? Lightning strike? System replacement? How
is your power?
What type of protection do I need?
A surge suppressor does exactly what its name implies, it suppresses
surges. This provides you with adequate protection against most lightning strikes, and
some line noise. Surge suppression does not protect you against brownouts or blackouts.
For this task an uninterrupted power supply (UPS) is needed.
How long will a UPS last during a
blackout?
A UPS is not designed to keep you running through extended blackout periods.
If you run a computer with monitor (standard workstation) on a UPS, you should expect to
have enough spare power to save your documents and shut the system down before the UPS
drains. A monitor draws much more power than the computer does, and will drain a UPS
quickly. If you are backing up a system without monitor (like a small server) you should
expect the back-up to maintain the system for 30-90 minutes at most.
Will my surge suppressor protect me from
lightning?
Nothing can boast 100% lightning
protection, but you can come close. When lightning strikes your surge suppressor, it is
designed to "absorb" most of the hit, destroying itself in the process, but
keeping excess voltage away from your equipment.
Lightning does not need a straight path to your computer to do damage. Lightning can enter your computer directly through the
power connection, phone line, cable modem, network connection, or indirectly by striking
an attached, unprotected peripheral (like a printer). In your house you wouldn't lock the
front door, but leave the back door wide open, in your computer, if you add a surge
suppressor, protect your phone input as well.
What are surges, line noise, blackouts,
and brownouts?
Surges and spikes:
Power surges are an increase in the voltage that powers your electrical
equipment. Surges often go unnoticed, often lasting only 1/120th of a second,
but they are much more common and destructive than you might think. According to recent
studies, your electrical equipment is constantly experiencing surges of varying power.
Some of them can be absorbed by your power supply while others can only be handled by a
quality surge suppressor. The most destructive power surges (like lightning) will wipe out
anything that gets in their way!
How they happen: In this power-hungry computer age, utility power systems are
often pushed beyond their capacity, resulting in unstable, unreliable power for consumers.
Overburdened power grids can generate powerful surges as they switch between sources or
generate "rolling surges" when power is momentarily disrupted. Local sources can
also generate surges - for example, if your neighbor starts up an electrical motor or the
office on the floor below you blows a fuse.
Line Noise:
The term "line noise" refers to random fluctuations - electrical
impulses that are carried along with standard AC current. Turning on the florescent lights
overhead, your refrigerator, laser printers, working near a radio station, using a power
generator, or simply working during a lightning storm can all introduce line noise into
your systems. Ever notice the
"snow" on your TV when you use a blender or a hair-dryer? That’s line noise
being sent back into your electrical system and up into your TV.
Line noise interference can result in many different symptoms depending on
your particular situation. Noise can introduce glitches and errors into programs and
files. Hard Drive components can be damaged. Network and modem traffic can experience data
errors. Televisions and computer monitors can display interference as "static"
or "snow," and audio systems experience increased distortion levels.
Brownouts
Brownouts are periods of low voltage in utility lines that can cause lights
to dim and equipment to fail. Also known as voltage sags, this is the most common power
problem, accounting for up to 87% of all power disturbances. Overburdened utilities sometimes reduce their voltage output to deal
with high power. Recent statistics show that the U.S. population tries to pull an average
of 5% more than utility companies can provide. The demand for power is rapidly increasing,
but the supply of power is not.
Damage to electrical lines and other factors can also cause utility
brownouts. Locally, equipment that draws massive amounts of power such as hair dryers, air
conditioners, or laser printers can cause momentary brownouts to occur.
Undervoltages are often followed by overvoltages - "spikes" - which
are also damaging to computer components and data.
Voltage variation can be the most damaging power problem to threaten your
equipment. All electronic devices expect to receive a steady voltage (120 VAC in North
America and 220/240 volts in many other parts of the world) in order to operate correctly.
Brownouts place undue strain on power supplies and other internal components,
forcing them to work harder in order to function. Extended brownouts can destroy
electrical components and cause data glitches and hardware failure.
Overvoltages burn out power supplies and other components and can cause
massive damage to your electronic hardware. Extended overvoltages can even cause fires as
electronics "fry" in the extra electricity.
Blackouts:
Power Failures, also known as blackouts, are the easiest power problem to
diagnose. If the lights go out, chances are you’ve had a power failure. Any
temporary, or not so temporary, interruption in the flow of electricity will result in a
power failure which can cause hardware damage and data loss.
Violent weather is the first thing that comes to mind, but there are any number of other
causes. Overburdened power grids, car accidents that bring down power lines, earthquakes,
lightning strikes, balloons, animals and human error are all likely sources.
Power Failures are more than simply inconvenient and annoying. They can cause
computer users to lose hours of work when their systems shut down without warning. Power
failures can even damage hard drives resulting in loss of all data on a system! Consider
the fact that a single power outage on high-traffic network can stall hundreds of users,
and you begin to see just how serious power failures can be. Even worse - when the power
returns, it often brings after-blackout spikes and surges! |
