Make you safer in a thunderstorm
2008-08-06

Lightning is a massive natural electrostatic discharge produced during a thunderstorm. Lightning's abrupt electric discharge is accompanied by the emission of light. The electricity passing through the atmosphere rapidly heats and expands the air, producing lightning's characteristic thunder sound. Aside from being a very real and dangerous threat to life, lightning is now a very real and dangerous threat to electronic equipment. Computer chips found in TV's, VCR's, radios, computers, modems, telephones, answering machines, garage door openers, etc. can be permanently damaged by relatively minor voltage surges. Lightning can induce tremendous voltage surges in household wiring. It can do this in many different ways. And the surges are insidious and for the most part are silent. They can occur with little or no warning. Therefore, an effective surge protection system is a necessity in every home, if it is to be safeguarded against these kinds of potential disruptions. Whole-House Protection A surge protector is an appliance designed to protect electrical devices from voltage spikes. A surge protector attempts to regulate the voltage supplied to an electric device by either blocking or by shorting to ground voltages above a safe threshold. The following text discusses specifications and components relevant only to the type of protector that diverts (shorts) a voltage spike to ground. Many people install low-cost surge arresters, or suppressors, that plug directly into an outlet, believing they are providing themselves with whole house protection. Unfortunately, this is not the case. Surge suppression must be accomplished on two levels. First is at the main panel, where the surge can be prevented from entering the house wiring, and the second is at the point-of-use, where any surge remaining on a line can be removed just before it enters an appliance or other electrical device. A surge arrester will divert heavy electrical surges into your grounding system, permitting your point-of-use devices to serve as sensitive electronic filters, shutting down noise on the line, as well as stopping any remaining line surges. If your home has a sub-panel located 20 feet or more from the main panel, you should install a second device to protect it, too. Surge arresters may be directly wired to the main panel and mounted either on the inside or outside of the panel box. The type that mounts outside the panel box is usually preferred in order to protect the breakers and circuits from explosive discharge. A better system for containing lightning surges, and the easiest to install, is a whole-house protection system in which the surge arrester replaces a circuit breaker in the main panel. Because you have to have a circuit breaker anyway, it makes sense to build the protection directly into it. This type of breaker has a red light that indicates whether or not the surge arrester is functional. Once you install the device, whatever it is wired to will be automatically protected. Though the protection system is contained within the device for a particular circuit, the entire house will be protected—not just that circuit. Point-of-Use Protection Providing surge protection directly at an electrical outlet is common practice because it is easy to do, you simply purchase the device and plug it in. No wiring needs to be done. This is called point-of-use protection. These types of surge protectors perform several layers of filtering to eliminate the noise on house wiring and prevent damage to highly sensitive circuitry. They are often used to protect personal computers and home audio-video equipment. Some point-of-use surge protectors electrically isolate their connected plug-ins so that the noise generated by a printer, for example, will not cross over to the computer. Be sure to buy a surge protector that has receptacles arranged in such a way that a plugged-in transformer will not block any of the unused outlets. Also look for one that provides telephone or modem protection. Safer Locations No place is truly 100% safe in a thunderstorm, but some places are safer than others. Larger, better constructed structures are better than smaller or more open structures. Fully enclosed metal vehicles with the windows rolled up are good shelters, providing that no contact is made with any exposed metal inside or outside the vehicle. When outside, avoid the following: High places and open fields Isolated trees Unprotected gazebos Rain or picnic shelters Baseball dugouts Communications towers Flagpoles Light poles Bleachers (stadium seating) (metal or wood) metal fences convertibles golf carts Water - ocean, lakes, swimming pools, rivers, etc. Metal-shafted umbrellas If you in an open area during a storm, position yourself close to the ground by squatting with your feet close together and on the balls of your feet. Crouch in a ditch if possible. Avoid proximity to other people (minimum 5 meters or 15 feet). Since lightning spreads when it hits the ground, minimize as much surface area between you and the ground. When inside, avoid the following: Phones - use of the land lines Anything to do with the use of water Being near windows and doors Using electrical appliances that plug into the wall Avoid contact with conductive surfaces with exposure to the outside such as metal door or window frames, electrical wiring, cable TV wiring, etc.