Computer components are vulnerable to
various kinds electrical fluctuations and can be damaged by electrical
discharges because of the delicate nature of the internal components.
Computers can be damaged or destroyed with high levels (lighting
strikes) or low levels (static electricity) of electrical releases.
Specifically, computers can be damaged by power surges and power sags.
- Power surge
– Also known as transient voltage, a power
surge is a dramatic increase in voltage above the normal flow of
electrical current. It is a temporary over-voltage. For example,
if a standard wall outlet in the United States increases from 120V
to 250V, there has been a power surge. A power surge lasts more than
three
nanoseconds (billionths of a second). If the event lasts one or
two seconds, it is called a spike. This increase in voltage is
enough to overwhelm the delicate components of a computer.
However, surge suppressors can help defend computer components
from power surges.
- Surge suppressors
– Also known as surge protectors, these can help guard against
electrical surges and spikes. Surge suppressors
work by diverting the extra voltage to the ground. Surge
suppressors use a component called a metal oxide varistor (MOV) to
divert the over-voltage. A clamping voltage triggers the MOV. If
the voltage is above the minimum for the clamping voltage, it is
diverted to the MOV. If this occurs, the over-voltage will bypass
the computer components.
- Uninterruptible Power Supply (UPS)
– An
uninterruptible power supply is another device that protects
against AC power issues. UPSs provide a limited supply of power in
the event of a power failure. Usually, a UPS provides enough time
to save and exit before lack of power causes the machine to turn
off. UPSs also help guard against power sags or brownouts.
- Power sag
– Also known as a brownout, power sag is the
opposite of a power surge. Power sag is an under-voltage in the
flow of electricity. Power sags result from over used wall outlets
or when power companies experience high demand for power.
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