Saturday, November 17, 2012

Too Much Power?

The least thought about computer component is the surge protector. Most people put careful consideration into how much processor power or how much memory they need in their system, but protecting those components is an afterthought. It's not uncommon for people to let us know that they can get power strips for their computers at Wal-Mart for five dollars, and they work just fine. Unfortunately, these are usually the same people who are coming in with hundreds of dollars in damage to their systems caused by power surges.

The first step to understanding why we need to invest in quality surge protectors is understanding why we need them at all. Everybody understands that if a bolt of electricity hits a power line near your house there will be a large electrical jolt. What most people don't realize is that there are smaller power fluctuations that occur in our electrical systems every day. These surges are usually small and short lived, so most electrical devices are unaffected. However, electronics such as computers and TVs have relatively small and delicate components that can easily be damaged by these fluctuations. When contemplating power fluctuations, it's usually easiest to compare electricity to something we have more experience with. I like to use plumbing as an example. Everybody is familiar with the idea that as you turn on more faucets in your house the water pressure to each individual faucet will drop because the pressure is being divided between the open faucets. We also know that if we shut off all of the faucets except for one that single faucet will have a sudden spike in pressure. The person that is using that faucet will recognize that they are all of a sudden getting a lot more water than they expected, and they will turn the water down. However, there is a short time between the water pressure jumping up and that person turning the water down where the water was gushing out of that faucet way faster than was needed. The same thing happens with electricity. When your refrigerator or air conditioner is running your electrical system will draw extra current from the power grid to compensate. When those appliances kick off there is a small delay where your system is suddenly getting more power than it needs. That electricity has to go somewhere, so everything that is still plugged in and turned on will experience a surge in electrical power.

A large power surge, like a lightning strike, can be dramatic and the effects immediately obvious. When you hear thunder and all of a sudden there is smoke pouring out of your computer, it's not too hard to guess what happened. However, smaller power fluctuations can have a cumulative effect on your system. While the effects are not immediately visible, over time they can do the same amount of damage. If we go back to the plumbing example, an average home system is designed to withstand 80 psi of water pressure. A large burst of 1000 psi of water pressure will produce immediate and dramatic results. Usually this would look like all of your pipes simultaneously bursting. However, having the water pressure spike to 100 psi several times during the day won't have any immediate noticeable effect. That doesn't mean that the damage isn't being done. Sooner or later all of your fixtures will start to fail, and if left enough time your pipes will begin leaking as well. Likewise, the circuits in your computer's components are designed to carry a certain amount of electricity. A lightning strike will cause many of them to burst dramatically and at the same time and routine but smaller fluctuations will cause them to fail one at a time.

If these fluctuations are happening constantly in most homes, how do we protect our computers from them? The answer is surge protectors. A surge protector is really just a power strip with an extra circuit that can absorb sudden bursts of electricity. This energy is then either released into a grounding wire or gradually released back into the main circuit depending on the design of the surge protector. These extra circuits have a rating of how much electricity they can handle. This rating is measured in joules. I would recommend purchasing a surge protector with a rating of at least 3000 joules. This will protect you from the small to medium power surges that are seen most often in people's homes.

The last point I want to make is that surge protectors work by sacrificing their own circuits in order to protect your electronics. Every surge that a power strip absorbs lowers it's performance rating for subsequent strikes. Over the course of four or five years, the protection of a surge protector can be completely exhausted even if you've never noticed a serious power surge. For this reason, most quality surge protectors on the market today will have an indicator light to let you know if they are still operating at an adequate level to protect your components. I would strongly recommend replacing your surge protectors every two to three years and making sure that any new surge protectors purchased have an indicator light so that you can visually see when they need replacing again.

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