NWA-PCUG Newsletter Article, August 2004
Computer Power Protection
by Ira Wilsker, APCUG BOD
Columnist for The Examiner, Texas; Radio Show Host and Police Officer
iwilsker@apcug.net
(click to email author)


Now that summer is upon us, and our air conditioners seem to cycle on and off endlessly, we may have noticed our computer screens flicker or shrink ever-so-slightly for a moment when the AC compressor powers on. With our intermittent yet common summer thunderstorms, we may have noticed our lights flicker, occasionally accompanied by a power outage of varying lengths. While these and similar effects may be an emotional strain upon us personally, they may also be an indication that we may need to protect our computers from unseen electrical damage.

The most basic form of electrical protection for our computers, which should be considered as mandatory for all computers, including notebook computers used away from the home or office, is a surge suppressor. Power surges, also referred to as spikes, are short term increases in voltage, often occurring when major electrical equipment, such as air conditioners or freezers are turned off. These surges and spikes can damage sensitive electronic devices such as computers, TVs, microwave ovens, and other devices. Surge suppressors to minimize the risk of damage are readily available in a variety of forms and prices, ranging from an inexpensive suppressor in the form of a power strip, to large box shaped devices that provide surge protection with line conditioning and a battery backup function. A recent review of the selection available locally at the office supply, electronics, and discount stores indicated a vast array of power strip type surge suppressors, ranging in price from about $3 to almost $100. One caveat is appropriate here; many users have a standard power strip connecting their computers to the wall plug. While almost all power strips offer some form of overload protection, typically with a circuit breaker, standard power strips offer no other protection for power related problems, and need to be replaced with a decent quality power strip that has a surge suppression function with a UL 1449 rating.

The ability of a surge suppressor to dissipate the surge or spike is measured in “joules”, with a higher joules rating indicating a greater ability to absorb and dissipate the excess voltage from the surge. Almost all surge suppressors have a limited life expectancy, and may wear out. Many of the better ones have an LED or other device indicating the proper functioning of the surge protection. It is a good practice to frequently inspect your surge suppressor, and to immediately replace it if there is even a hint or suspicion of malfunction. Power surges are one of the major killers of computers and other electronic devices. In my house, each of my major electronic devices, including TVs, microwaves, stereos, cordless phones, and of course computers, is connected to a functional surge suppressor. I also carry a good quality surge suppressor – power strip in my notebook computer case which is always used whenever my notebook is plugged in.

While the primary function of a surge suppressor is to protect plugged-in electrical devices from surge related damage, many of the suppressors on the market also provide additional functionality. Common in most better suppressors is an electronic noise filter, which reduces the electrical noise, often referred to as “RFI” or “EMI” interference, carried through the power lines. This electronic noise may be thought of as a type of static, and commonly comes from a variety of transmitters, welding devices, printers, lightning, or other sources. This type of line noise can cause errors in computer programs and data files, and possibly also damage some hardware components. In purchasing a surge suppressor, I recommend that one be purchased that includes electronic noise filtering.

I have repaired countless computers where the modem was “fried”, or destroyed by a power surge. It is widely known in professional circles that power surges and spikes can also come through a phone line, as well as a coax cable, network cable, or other form of data connection. Many surge suppressors also include one or more protected lines explicitly for a phone or fax cable, TV or satellite cable, or other types of network cable. For those of us that still use dialup connections to the internet, or use fax machines, a surge suppressor that has a phone jack should also be a necessity. The phone plug from the wall connects to the jack in the suppressor, and another cable is used to connect the suppressor to the modem or fax machine. Generally, there is no significant degradation of signal while connected to a fax machine, but some 56K modems may suffer a slight degradation of signal or speed. This slight performance is a small price to pay for the added protection provided by the suppressor. All of my phone lines and cable TV coax is connected to the same surge suppressor that protects the device they are connected to.

As an added benefit, many models of surge suppressors also carry some form of insurance coverage to repair or replace devices connected to them from covered perils, often including lightning. The amount of coverage provided is often high, but is sometimes used as a marketing gimmick. As with all types of guarantees and insurance, be sure to read the fine print, and follow explicitly the directions for filing a claim.

Better safe then sorry.

There is no restriction against any non-profit group using this article as long as it is kept in context with proper credit given the author. The Editorial Committee of the Association of Personal Computer User Groups (APCUG), an international organization of which this group is a member, brings this article to you.

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