NWA-PCUG 06/2000 NewsLetter Article 18861 N. Hwy 112, Springdale, AR 72762-9303 Bob Click is a Nationally known writer and is featured in hundreds of user group newsletters. There is no restriction against anyone using the article as long as it is kept in context, with proper credit given to the author. Please notify the author via email at dealsguy@mindspring.com. This article is brought to you by the Editorial Committee of the Association of Personal Computer User Groups (APCUG), an International organization to which this user group belongs. To Surge, Or Not To Surge by Bob Click, Greater Orlando Computer User Group [dealsguy@mindspring.com] People purchasing new computers often ask what to do about power line and lightning protection. To emphasize the importance, it's better to understand household electricity, what it is and what affects it. Lets analyze all this, but in a visual manner. Electricity in your home (in the USA) is rated at an "average" of 117 volts and is referred to as "AC" (Alternating Current). There are basically two different types of electrical power, AC and DC. Direct Current (DC) is so named because it maintains a near constant voltage of a certain value at all times, such as the 12-volt system in your automobile. DC is not normally used in the home any more except in unusual situations. Alternating Current (AC) is electrical power with the voltage constantly changing from one polarity to another (from positive to negative to positive, etc.). For long distance transmission, DC decreases in voltage and is expensive to convert from one voltage to another. AC maintains its voltage better with the assistance of transformers that greatly increase the voltage for long distance transmission, then drop it back down for home use. To illustrate AC electricity graphically, lets visualize or draw a large "S" laying on its side with a horizontal line running through the middle of it. Let's call the horizontal line "0" volts, and the bottom of our S will be - 117 volts. The top of the S going above the horizontal line will be + 117 volts. Note that the value of our electricity starts at 0 volts dropping to 117 negative volts, then rises back up to the "0" volts line, continuing on up to positive 117 volts, then back down to the 0 level as the electron flow continually reverses. In our electricity, this complete "sine wave" takes place 60 times each second, continuing one after another in our graphical representation of electricity in your home. In a perfect world, the voltages I described would remain constant, but in reality many things affect them. Electric Companies try to regulate power at a proper level, but certain conditions can still affect those voltages. For example, in hot weather many people turn on devices using large amounts of electricity, such as air conditioners, greatly loading the power line. The Electric Company has to compensate, although the voltage "could" still decrease if power lines are overloaded. If loads suddenly get lighter, the voltage can rise (dangerous for your computer) in spite of the Electric Company's regulation. Sometimes a factory or business in an area has equipment using high amounts of electricity causing sudden surges up or down quicker than Electric Company equipment can adjust for. Some surges described would be seen as "spikes" in the graph you just drew, not to mention a possible low-voltage situation. Lets draw a very narrow V upside down on top of the + portion of the sine wave. That will be the spike and you can see that it would exceed the 117 volts your computer equipment is designed to operate at, possibly damaging components in its electronic circuitry. In your own home, turning on a high-consumption device (such as a toaster, or especially an air conditioner) can cause voltage spikes in the home's electricity and also causes spikes when turned off. In my case, the computer room is in one end of the home and the electrical service box (entry point) is on the other end, making a long electrical run to the plugs in my computer room. Turning on the copier in that room, which initially draws heavy current, causes my computer's Uninteruptable Power Supply (UPS) to "beep" me that the supply voltage has gone below acceptable limits. That didn't happen when my copier and computer were on plugs closer to the power panel. Lightning often strikes power lines and the resulting spikes can be carried down the line into your home's distribution system and into any unprotected electronic equipment. The Electric Company can only regulate so much, so lets examine protection for all this. Surge protectors have unique electronics built-in that can smooth out those surges, dips and spikes in the electrical sine waves just illustrated and are designed to maintain the power's voltage at the correct level. The cheaper ones have a minimal amount of components and are actually not good protection. Many people prefer to turn on the computer, monitor and peripherals with one master switch (laser printers should not be included). That's fine if you have surge protection to handle such a surge, but you should check that capability when choosing your protection. If it doesn't list those ratings in the brochure, it's probably not that good, so look for better equipment. Mine specifically stated that in its paperwork. Good surge protectors will probably run about $60.00. Many also carry up to $25,000 insurance protection for excessive surges and lightening strikes. However, read the brochure to see if it's good in the event of a direct lightning strike. Some aren't. You might think that if one is good, two might be better. Not necessarily, I'll explain later. If you can afford it I recommend an Uninterruptible Power Supply (UPS). Why? Many areas often have a very short interruption of the power that doesn't effect most clocks, VCR, etc., but the computer notices. All of a sudden, it is rebooting and you've lost everything since your last "Save," not to mention the improper shut down and possibility of file corruption. Everyone has had power go out at one time or another and that's when a UPS excels if you're using your computer. UPS devices provide surge protection as well as a temporary electrical source if the power fails. They mostly come in two types. Some switch extremely fast to a backup battery, automatically keeping your computer going. Another type lets your computer actually run off the battery and keeps it fully charged to supplement what your computer needs. I have no preferences there. They are available in different capacities. For the home computer, I suggest a 400 volt/amp capacity. Should your power go out and fail to come back on, it offers temporary power for easily halting your task, saving your data and shutting the computer down properly, probably allowing a maximum of 20 minutes. A cheaper one (with a 250 volt/amp capacity) allows about six-to-ten minutes. That's still OK if you're at your computer when that happens and work fast to shut down. These times are for the average home computer and monitor, not including a printer. A laser printer should not be on the same surge protection as your computer and monitor because of a laser's high power consumption. A UPS is not necessary for a printer or scanner, however, separate, but adequate, surge protection is advised. While the UPS is also a surge protector, it is typically not as good in the role of a dedicated surge protector, but will still do the job well enough. So why not use both? Two surge protectors will combine their ratings. But if combining a surge protector and UPS, microsecond timing involved in surge protection could conflict with the timing in the UPS. Surge protection companies say you can use a surge protector in the line "before" a UPS, but not after if you really want to use both. In fact, in the event of a lightning strike, their $25,000 insurance may be void if they find you had both and connected them backwards. A "Smart" UPS can also be upgraded to let your computer keep a continuous log of the power's voltage. Other software is available that will automatically save data, then shut down your computer if it is unattended when the power fails. Want another reason to buy a UPS --- while a good surge protector can smooth out the spikes and maintain a proper voltage for you, "low voltage" on overloaded lines can also damage your computer equipment or cause data errors. A surge protector cannot make voltage out of thin air to accommodate a low voltage condition, but a UPS has backup batteries to compensate for it. It's a known fact that lightning strikes ride in more on your phone line than they do on the power line, so it's also a good policy to include surge protection for telephone lines. Here in Florida, we are in the "lightning capital of the world" so many Florida residents make it a policy to unplug the power and phone lines to the computer as an added security during lightning storms (in the event of a direct hit), even though they own surge protection. Does that fully insure me? Not necessarily -- one of our club members did just that, dropping the power cord on the floor next to his receptacle. When he received a close lightning strike, it jumped from the wire inside the wall, through the wallboard, to the power cord attached to his computer. Considering the distance between the earth and clouds, that short jump was no problem for lightning. His case was certainly unique though. In summary, my advice is to buy high quality surge protection. Better advice (in my opinion) is to buy a UPS for your computer and monitor and separate surge protection for a laser printer or scanner. It's also important to add telephone line protection, either incorporated in the power's surge protector (or UPS), or separate telephone line protection. The dual protection is better because of the built in ground to shunt away the surges. It always appalls me when I see a salesperson sell somebody a $1500 computer with a $12.95 surge protector, which is almost useless. Surge protection is sort of a "pay me now, or pay me later" situation. Surge protectors and UPSs are rated in "joules" and I recommend a rating of 90. Lesser ratings will still protect your equipment, but will often destroy themselves when hit by a surge if their rating is exceeded, and will require replacement. Surge protectors are mainly for upward surges and spikes. UPS devices can handle both upward and downward voltages, but are not quite as good at surge protection. In spite of everything I have described above, "absolutely nothing" will protect you in the event of a direct lightning hit. One other thing to keep in mind is that the "metal oxide" devices in most surge protectors do wear out and it's wise to replace a surge protector about every four years. If the many choices of surge protection confuse you, seek a "knowledgeable" person in your user group for advice. Don't depend on the store's salesperson. * Special thanks to my friends Paul Witherage from "Sarnia Computer User Group" and Ron Klair of "Central Florida Computer Society" for critiquing this article and offering their suggestions to improve it. * Bob Click is a Nationally known writer and is featured in hundreds of user group newsletters. This article is brought to you by the Editorial Committee of the Association of Personal Computer User Groups (APCUG), an International organization to which this user group belongs.