Power surges happen in the blink of an eye, and can do major damage to your computer, printers, monitors, external hard drives, and more.
You may think you’re adequately protected, but you may not be. Many surge protectors do not block surges well enough at all. The effect that surges have on your sensitive equipment is cumulative. This means that many small surges, none of which are enough to damage your computer by itself, can each bring damage that gets worse each time it happens. Eventually, the computer will not boot up any more, or other strange behaviors can result.
In order to have enough protection, you need to learn about “Joules”. The effectiveness of a surge protector is measured in joules. The higher the joule rating a surge protector has, the bigger the surge that it can stop. We recommend surge protectors that are rated at over 3900 joules. Many common surge protectors are rated at between one and two-thousand joules. These do not stop nearly as many surges as one with a rating of 3900 or above. Many surge protectors don’t even state the rating on the packaging. Stay away from these. Play it safe and get a surge protector with a high rating.
An excellent, detailed article on protecting against surges can be found at the National Institute of Science and Technology web site: http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf.