by Don Rittner

You’ve invested lots of hard-earned money into your computer and peripherals. Certainly you don’t want them to go up in smoke because of a sudden power surge!

To help protect your computer, and those other electronic components connected to it, most computer sellers recommend adding a surge protector or suppressor.

If a sudden power surge comes into your home or work space, surge suppressors are designed to grab that extra dose of electricity and displace it safely, and hopefully not through the important and sensitive electronics of your computer’s motherboard. However, many surge suppressors simply do not work properly. Those five-dollar surge suppressors may actually do more harm than good.

Think of a surge suppressor as a dam against a sudden flood of electricity. It protects your vital electrical circuits from damaging charges of electricity that come through a power cord by taking that sudden surge and slowly releasing the water over the dam.

Anything electrical from your computer, modem, printer, scanner, or other electrical device has to be plugged in, and this leaves them vulnerable to power surges. Most people are familiar with the most spectacular surge - lightning - that enter into power lines and fry everything in their paths.

Lightening is quite common. Every 3 seconds, a lightning strike starts a forest fire somewhere in the world. Lightning strikes can send up to 6,000 volts and 3,000 amps through your system in as little as 50 microseconds - enough time to reduce your computer circuits to a smoking heap.

While getting your computer struck by lightning is not as common as starting a forest fire, other power surges happen constantly. They are quiet changes in voltage caused when equipment in your building cycles on and off. However, while these surges are tiny compared to lightning bolts, they can still easily reach 1,000 volts. Gradually, they cause deterioration in circuits and lead to real problems down the road.

Surge suppressors are supposed to intercept power-line surges no matter how small or large - to prevent a computer meltdown. The vast majority of surge suppressors are designed to work in two ways simultaneously.

Inside surge suppressors they have small devices called metal oxide varistors, called MOVs, for short, designed to absorb surge damage before it reaches your equipment. Basically, MOVs commit suicide to prevent surges from reaching your computer. Secondly, they take all the excess surge energy and send it to the "ground" wire away from the main circuit.

MOVs do one thing and that is diverting surge current. However, MOVs wear out with use. As more surges are diverted, the MOVs life span gets shorter, and complete failure is the end result eventually. How many surges a particular MOV can handle is unknown. You often know when it is too late, after they fail? There is no warning, and while failing, they can reach very high temperatures and actually start fires.

They've also been known to explode and burn when hit by surges. Naturally, this often happens when no one is around to put out the fires.

In 1995, the fire marshal of the Bainbridge Island, Washington, fire department issued a warning to island residents, urging them not to use low cost surge suppressors enclosed in plastic cases. In one year, between 1994 -1995, two families on Bainbridge Island lost their homes due to fires that were caused by using multiple outlet power surge suppressors. In 1997, one company had to recall theirs because the surge protectors had "undersized wires, loose connections and improper grounding, which present fire, shock and electrocution hazards."

The problem found with some MOV components is that over a period of 18 to 24 months the materials used begin to break down. As a MOV ages, the operating characteristics change making it more sensitive and likely to dissipate more heat.

While it seems like common sense to avoid using surge suppressors enclosed in plastic cases, for a while the vast majority of surge suppressors were enclosed in plastic cases.

Another major problem is caused by shunting (moving to an alternative course) surges to the ground wire - it’s simply dangerous. Your individual stereo, radio, or computer is connected to each other through the ground circuit. Conventional surge "suppressors" using MOVs direct destructive voltage into the network through the ‘back door’ when they divert surges to the ground wire.

Underwriters Laboratories, whose "UL" seal is easily recognized and looked for when it comes to electrical devices in America, has understood the potential fire hazard posed by the failure of certain types of surge suppressors. In the new version of their Standard UL 1449, Transient Voltage Surge Suppressors, surge suppressors must now pass a more stringent fire-safety test to earn the "UL 1449, Second Edition" label. To meet this standard, some manufacturers have gone to using metal enclosures, some have converted to high-temperature plastic, and some are using thermal cutout devices.

Next week. Types of surges and how to buy a good surge suppressor.