by Wayne M. Krakau - Chicago Computer Guide, January 1993

Does anybody out there have decent power protection? From what I have observed, not many do. While most people know that some protection is needed, most are being scammed by companies selling inadequate protection either as a part of a deliberate strategy for winning bids or from just plain ignorance.

At the low end of the power protection equation are surge suppressors. Don't even think of buying suppressors without Electromagnetic Interference and Radio Frequency Interference (EMI/RFI) protection. These disturbances can cause mysterious lockups or even undetected data changes.

Every computer and peripheral device on the network should have at least this level of protection. For machines with modems, use suppressors that include phone line protection. On networks that don't use fiber optic cabling, the underlying material in the cable is copper, a great conductor. If an inadequately protected PC gets hit by a major power disturbance, either via its power cord or from the phone line (through a modem), not only will that PC potentially get barbecued, but the electrical disturbance can get to the LAN cable via the network interface card (NIC). Once on the LAN cable it can get to every part of the network, including the precious file server.

The scam here involves differentiating between the various type of suppressors and other devices that resemble suppressors. Many computers are being "protected" by multi-socket temporary taps (translation: fancy extension cords) rather than actual suppressors. They are normally marked as such on the back.

Other computers are protected by low-end suppressors that aren't designed to provide computer-grade protection. They are good for protecting household appliances and some business equipment (try toasters and pencil sharpeners), but shouldn't be used on computers or any other delicate electronics. (I wouldn't even use them on a modern stereo system.)

A step up from these devices are the low-end computer-grade suppressors. These provide a limited but reasonable amount of protection (varying by brand and model), but are made with circuitry that weakens every time it protects. They are like the ablative tiles on the nose of the space shuttle. Every re-entry (or electrical variance) damages the tiles (suppressor), eventually forcing replacement. The estimated life of these suppressors varies depending on the quality of the electrical power available, but is generally about one to two years. When (not if) they fail, they do so in the closed position. This means that they continue to provide power, but without any protection, while giving no indication of the failure. The replacement cost plus the danger of undetected failure keeps low-end computer grade suppressors from being cost effective. This is a prime scamming opportunity.

The best surge suppressors cost only a little more than the low-end models. I tend to use sixty dollars (list price - real prices vary) as the lower limit for a six or seven socket suppressor with EMI/RFI protection and a six foot or longer cord. Anything priced below that makes me suspicious. Upon further investigation, it usually turns out to be a low-end model.

These high-quality suppressors are not damaged by normal operations, and, if stressed by extraordinary electrical events, fail in the open (off) position. Many of them can also detect and report (via LEDs - Light Emitting Diodes) on faulty wiring. Naturally, power is cut if wiring errors are recognized. Most manufacturers have models available with telephone line protection for those computers with modems or fax modems.

Surge suppressors are only fully effective if the underlying voltage from the wall socket remains somewhere near 120 volts. If, for example, you are in an older building, you may find that the building wasn't designed for the electrical load that modern lighting and office equipment demands. Your power might not fail outright, but may vary considerably from the 120 volt standard resulting in brownouts and sustained overvoltages. The fan on your PC might audibly change speed, ranging from an unnaturally quiet whisper to full tornadic proportions. Your monitor image boogies to its own bizarre rhythm or shrinks and grows as if inhabited by some disembodied heavy breather.

This is where a voltage regulators (also called line conditioners) and power conditioners come in. They can filter as well as the best surge suppressors, but can also regulate the output voltage, even when the input voltage varies far from the 120 volt standard.

The traditional mechanism for this regulation is a ferro-resonant transformer. This is basically a large chunk of soft iron set up as a transformer similar to those that provide power to an external modem. In this case, however, the windings on each side of the transformer match so no voltage conversion takes place. This transformer and its associated circuitry can keep the output at a smooth 120 volts even if the input power gets very dirty or varies considerably from 120 volts.

A disadvantage of the plain transformer used in a line conditioner is the large amount of heat generated as the transformer absorbs the ups and downs of the incoming power waveform. This is accompanied by noise from the required fan. From past experience, I can tell you that there is an extra noise - a kind of raspy growl that can be quite loud - that emerges from the transformer every time there is a major voltage variance. It can be very startling if you haven't been warned. A more worrisome problem is the extra defects in electrical quality that can be created by the transformer itself.

Newer (and more desirable) types of voltage regulators, the power conditioners use advanced electronics combined with a special transformer to match the protective abilities of a plain transformer, but without the electrical distortions.

Another possible drawback to both kinds of conditioners is that they can suffer in comparison to some simple UPSs (Uninterruptible Power Supplies). The prices of these two categories can be so close that you may want to skip the conditioner and go right to the UPS.

In surge suppressors, my choice has recently changed to the American Power Conversion (APC) "Plus" series of suppressors. They provide extremely high quality protection at a competitive price. They have seven sockets as opposed to the more common six. They have cleverly placed their sockets sideways in relation to the longest dimension rather than in line. This means that a transformer (power brick) placed in a single socket won't block one or two additional sockets as it would in other manufacturers' products. Their final advantage is a warrantee that allows for replacement of the suppressor if it fails and for the protection for up to $25 thousand of equipment that is plugged into the suppressor.

As for conditioners (line and power), I have usually been able to use a small UPS as an alternative. If I do need voltage regulation, I would opt for a power conditioner rather than the older line conditioner.

Tune in next month for a continuation of this POWER-full subject, when I will cover UPSs.

1993, Wayne M. Krakau