Power Problems
Alternating current (AC), which is “food” to PCs and other network devices, is normally 110 volts and changes polarity 60 times a second (or 60 Hertz). These values are referred to as line voltage. Any deviation from these values can create problems for a PC or other network device. Power problems fall into three categories:
* Overage
* Underage
* Quality
Power Overage Problems
During a power overage, too much power is coming into the computer. Power overage can take two forms:
* A power spike occurs when the power level rises above normal levels and then drops back to normal in less than one second.
* A power surge occurs when the power level rises above normal levels and stays there for more than one or two seconds.
Typically, power surges last longer than a second or two, and they may last for several minutes.
Two types of devices are used to protect computers and other network devices from power overage problems:
* Surge protectors
* Line conditioners
A surge protector contains a special electronic circuit that monitors the incoming voltage level and trips a circuit breaker when the overvoltage reaches a certain level (called the over- voltage threshold). The problem with surge protectors is that the threshold is set too high to be safe.Nor does a surge protector protect against power surges and spikes that are lower than the threshold. For the most part, a surge protector is better than nothing, but not by much. It is really only a multiple-outlet strip and should not be considered anything more.
Line conditioners are a much better choice for protecting against surges and spikes. Line conditioners use several electronic methods to “clean” all power coming into them. An Uninterruptible Power Supply uses a battery and power inverter to run the computer equipment that plugs into it. A battery charger continuously charges the battery. The battery charger is the only thing that runs off line