Protect Your Electronic Systems from Spring & Summer Lightning Storms

In the Southern United States lightning storms can occur year-round, but in the Northern half they're typically a sign that warmer weather is here to enjoy for a while. They also break up the monotony of calm sunny days with a dramatic natural show which leaves behind a calming after-feel of moist ionized air. For many people this is an enjoyable experience, but along with it comes a down-side that requires some attention. Our increased reliance on electronics for work, entertainment, and play makes us more vulnerable to the power of a million-volt discharge traveling miles through the atmosphere. While a direct strike can overwhelm almost any defensive measure, these are rare occurrences for the individual, and anything else can usually be defended against with complete success.

Here's a list of measures that can reduce, if not eliminate, the chance of property and equipment damage, as well as protect the personal safety of you and your family:

Install a lightning rod. This may seem impractical or unnecessary for most people but these devices have been preventing property damage and personal injury for over 200 years. It is believed that Benjamin Franklin invented this device in the 1700s and was so appreciated for the building fires it prevented at that time that he was awarded with the Royal Society's Copley Medal in 1753. The principle is to attach an air terminal (the rod) at the highest point of the building, with a heavy braided copper wire connecting the terminal to a grounding rod driven into the earth. Braided wire is used because it has the most surface area, and therefore the least resistance to the flow of current from a lightning discharge - this is known as the "skin effect". The operation of this system gives the lightning discharge a safe, non-destructive path to earth rather than it taking a destructive path through the building material (causing a fire), or connected utilities such as the electric, telephone, or TV cable lines. The latter occurrence can destroy equipment that's connected to these utilities or cause serious shock to anyone inside who would be in contact with them.

Unplug/disconnect your equipment. Obviously this only works when you're at home to do it, and aware of an approaching storm in advance. It is the single most effective means, however, to prevent lightning damage to your equipment. Since you don't want to be grabbing a power cord when the lightning is already striking in your area it's best to know at least a half-hour to an hour beforehand that a storm might be approaching. Some excellent information sources are your own local weather service, The National Weather Service Storm Prediction Center, The Weather Channel , and Vaisala.com. Make sure to disconnect not only the electric power but the incoming phone, cable, and Internet lines as well. Also, be sure to properly power-down your equipment first to prevent loss of data or personal settings.

Use surge suppressors or UPS units. While these cannot guarantee 100% safety, they are very effective against most circumstances and fairly affordable. They also give you the peace of mind of not worrying about being home when there's a storm, and eliminate the inconvenience and hassle of running around the house shutting down and disconnecting everything, and then reversing the process after the storm passes.

Surge Suppressors - These devices use components called MOV's (metal oxide varistors). They are usually rated in two ways: Response sensitivity - referred to as clamping voltage - is the voltage at which point the device activates to divert or short-circuit the voltage surge or spike. An average value for a consumer market unit is about 400 volts. Although this is several times the normal operating voltage of a computer or other electronic appliance, it is usually low enough to prevent damage since the "clipped" surge or spike normally has a very short duration. The other rating is the amount of electrical energy that the device can absorb without being destroyed, and is usually expressed in joules. Since lightning strikes are immensely powerful a higher "joule" rating is always better. It would be impossible to find a device that could handle a direct lightning strike, but because they statistically strike some distance from the home or business their energy is able to dissipate before reaching the surge suppressor.