 | Dave Geist
has 25 years of experience with computers and holds A+, Network+ and CNA certifications. He enrolled at Kansas State in 1996 and majored in Electrical Engineering, and worked for a power utility company in Topeka for 2 1/2 years before moving to Wichita to start his own PC repair service business and joining AmerITT, (American Independent Information Technicians), located at 532 S. Market Suite #205 in Wichita. You can reach Dave through AmerITT at (316) 264-5599 and for further information please visit their website @ www.ameriit.com |
Computers & Software
2004-08-01 11:28:00
Lightning and surge protectors
: The power pole outside my brother's house got hit by lighting during one of the storms we had a few weeks ago. He had his computer plugged into a surge protector but his computer was destroyed anyway. Why didn't the surge protector work?
ANSWER: A surge protector does a pretty good job of keeping a safe voltage at the power cord of your computer. They are designed to allow excess voltage to be safely diverted away from your computer and any other device you have plugged into it. I suspect that the lightning bolt that hit your brother's power pole created a power surge that was more than the surge protector could handle.A surge protector does its best work protecting your PC against the most common sources of power surges, mainly big power demanding devices such as TV sets or motors in air conditioners. These devices draw lots of power when they are running, so when they turn off the laws of physics take over and a power surge appears on the power line. The bigger the motor, the bigger the surge is when that motor is shut off. While things like lights, hair dryers and electric blankets are unharmed by these surges, our PCs can be damaged by them fairly easily.Surge protectors are valuable insurance to help protect your PC. When you are shopping for one, look for the model with the highest rating in joules. Joules is a fancy way of saying how much power the surge protector can take and still protect your PC. A rating of 200 joules is ok, but a rating of 600 joules is better. A higher joules rating is better.Another rating you should pay attention to is the clamping time, which is how soon the protector will do its job when it is hit by a surge. You want a protector to work quickly, so a lower clamping time is best.Also look at how many load watts the protector can handle. A 200 watt protector would be ok for a laptop, but a desktop PC needs at least a 600 watt protector. For wattage rating, bigger is better.Some surge protectors also feature jacks for your phone modem and cable TV. These are also good features to consider because power surges can find a way directly into your PC on these lines as well.Some cheaper surge protectors are designed to work like a safety fuse and burn out when they function. Although you can still use your PC, they lose their ability to protect your PC once they have operated. You have to visually inspect the cheap protectors to make sure they are functional. I do not recommend these type of surge protectors because it is easy to forget to check them. Prices will vary from store to store, so shop around and compare features and prices.Surge protectors are valuable protection because you never know when your PC is being exposed to damaging high voltages. My surge protector has an alarm that sounds off for two seconds when it isolates a voltage surge, and I hear it beep a few times a week.Lightning striking a power line outside your house will certainly create a power surge. Lightning strikes on power lines are common, and the electric power industry does a great job to prevent lightning strikes from entering our homes. Your brother's house suffered a rare fate: a direct lightning strike to the power pole outside his house.Lightning bolts are at least 1 billion volts and deliver between ten trillion (10,000,000,000,000) to 200 trillion joules of energy. When the lightning bolt struck the power pole, most of that power was safely diverted by the lightning arresters on the pole and power line. So let's assume that 99.999999 percent of the lightning's energy was dealt with safely. That still leaves at least 10,000,000 joules of energy on the power line in your brother's house. A really good surge protector will protect a PC from about 600 joules of energy. The surge protector on your brother's PC was simply overwhelmed. The best way to protect your PC from a lightning strike is to unplug it during a thunderstorm.If you are among the brave who say 'it'll never happen to my PC', I hope you are backing up your data files on a regular basis.
