They're important, but they're not all created equal. Now, there are new government specifications to help you decide the level of protection you need.

The scene plays daily in electronics stores across the country: A customer takes infinite care in buying hardware, agonizing endlessly over monitor size, hard disk space, RAM capacity, CPU frequencies, printers, modems, CD-ROM drives. Now it's time to ring everything up.

"Oh, by the way," says the salesperson, holding up an unidentified electrical object, "you'll need one of these."

"What is it?" asks the customer.

"A surge suppressor. It protects your system from electrical surges. It's important."

"How much?"

"We're having a special, $29.95."

"O.K."

Business scenarios are much the same. Only the vocabulary - file servers, networks, etc. - and the numbers are different. Surge suppression remains a brief afterthought.

The use of networks has mushroomed, and today's ultra-fast, ultra-sensitive computers are far less robust than the systems of the 1980's. The problem is surely far worse today. Surge protection is vital - especially since inappropriate suppressors can actually cause failures. Choosing the right surge suppressor deserves the same careful consideration you give to other hardware purchases.

That wasn't possible in the past. Electrical surges were mysterious things, and surge suppressors faced nothing like the technical scrutiny trained on products such as cars, stereos, phone systems, televisions and VCRs - not to mention computers, printers, modems and monitors. A Transient Voltage Surge Suppressor (or TVSS, as it's known in the business) was pretty much what the manufacturer said it was. But the high cost of surge damage made two things increasingly obvious: The average TVSS, using 30 year old technology, was notoriously unreliable and unpredictable; and a lack of stringent industry standards made it all but impossible to make informed buying decisions.

All that changed in 1996, when the government issued its first Commercial Item Description (CID) for surge suppressors. CIDs are standards that the federal government uses for its off-the-shelf procurement. For surge suppressors, government experts delineated various classifications to measure performance, reliability and mode of suppression. Here they are:

Performance. How much surge voltage does a TVSS let through? It's called the Suppressed Voltage Rating (SVR), and it's the only measure of effectiveness that really matters. The government lists three product classes:

• Class 1 products have suppressed voltage ratings of 330 volts. That is, under specified test conditions, their measured suppressed voltages were 330 or less.
• Class 2 products have suppressed voltage ratings of 400 volts
• Class 3 products have ratings of 500 volts.

Reliability. How long does a TVSS last? How many surges - really strong surges - can it handle? The government defined three grades of TVSS endurance:

• Grade A products must be certified to have passed 1,000 surges of 6,000 volts and 3,000 amps without failure.
• Grade B products must pass 1,000 surges of 4,000 volts and 2,000 amps.
• Grade C products must pass 1,000 surges of 2,000 volts and 1,000 amps.

Unclassified products haven't met even the minimal standards of Grade C. Think of them as Grade D.

Mode of suppression. How does a TVSS handle surge energy? As things currently stand, there is only one measure: Either it shunts surges to ground or it doesn't. Products that divert to ground can actually damage electronic networks, because network components are linked to each other through the ground circuit. That's the gist of the government CID:

• Mode 1 products protect the ground circuit by not diverting surge energy to it.
• Mode 2 products contaminate the ground circuit.

That's it - performance, reliability and mode of suppression - all neatly laid out to help you choose the surge suppressor you need. So how do you know where a particular surge suppressor fits? The only possible way is to look for certification by Underwriters Laboratories, or other NRTLs (Nationally Recognized Testing Laboratories). Until early 1996, UL safety certification standards were far lower than those set out by the government CID. As a result, many surge suppressors carry the UL label but have not been tested to the newer, stricter government standards. Look for certifications that specify CID Class, Grade and Mode. (You'll see the key words "UL 1449" - not just UL 1449 2nd Edition, which is the basic standard). They're the only measures that really tell you what you're buying.

Small investment, big protection

Now you're ready to choose the right TVSS for your electronic systems. If you're putting together a network - and that includes a network as simple as a self-contained computer-monitor linked to a printer - then you'll want to avoid Mode 2 products. They're open invitations for surges to come in and fry the entire network. If you're investment is modest and replacement costs are no concern, you can consider Class 3 suppressors and let price be your guide. The same reasoning applies to units rated Grade B or C in reliability. (We recommend avoiding unclassified products not certified even to minimum government standards. If you are currently using or are considering installing an unclassified or Grade D surge suppressor, plan a replacement schedule starting no more than six (6) months after initial use).

Zero Surge Inc. was the first company to have its products certified to the highest CID rating using the new UL testing program. Unlike conventional surge suppressors, Zero Surge products don't shunt destructive surge current to ground - and they don't deteriorate with use. Your networks start safe and stay safe. In fact, they'll still be safe long after they're obsolete. Every Zero Surge unit comes with a 10-year limited warranty and a lifetime service contract. The cost? More than $29.95, but a whole lot less than a computer network - or a single CD-ROM drive, for that matter. It's an easy call.

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