POWER PLAY - PART 2
 

by Wayne M. Krakau - Chicago Computer Guide, September 1997
 

This is a continuation of my column on the factors conspiring against you to damage your computer systems through bad electrical power. I’ve already covered the attack on your system from the power company and from the internal power supply. This article covers the part in between - your building.
Inside electrical wiring and its associated circuitry is generally designed (or in older building, redesigned) based on the National Electric Code (NEC), developed in the 1930's. This code was established to provide safety and standardization for electrical systems. The emphasis was decidedly on safety, proving the old adage that if enough voters die (here from preventable fires and electrocutions), eventually, even the most jaded, self-serving politician is moved to act. (Though being dead in Chicago has not always been an absolute disqualifier for voting.)
Microcomputers, however, are designed based on the much more exacting Institute of Electrical and Electronics Engineers (IEEE) specification for electric power. These standards have been a work in progress since before there were microcomputers, but, due to the time lag inherent in standards creation, have only recently been fully approved. Luckily for manufacturers of computers and related equipment, the proposed standard remained steady enough over time to use as the basis for their designs.
Now, here’s the fun part. The electricians who install and maintain building electrical wiring and equipment, and the inspectors who approve them are trained based on the NEC, not the IEEE standards! To test for good power, they use the AC voltage function of a simple volt-ohm meter worth $20 to $120 depending on how fancy it is, which only provides an average (actually the RMS, or root-mean-square) of the actual voltage. To test for a good ground, they use the continuity function or, if they are really conscientious, the resistance function of a volt-ohm meter. This gives only the broadest indication of the true conditions. An appropriately trained, experienced engineer would use something like $15,000 to $20,000 worth of sophisticated equipment, along with a good deal of professional interpretation, to determine the reliability of an electrical system.
(A note to anyone who thinks I don’t like electricians: My sister is one! She has worked for years in the dangerous environment of an international airport. Initially, when she wasn’t diving for cover to avoid being sucked into or exhausted at by jets, sliced, diced, or propwashed at by propellers, or outright run over by planes, she was ducking passes or dodging derogatory remarks from her coworkers. After she proved herself, her treatment improved. Luckily, she is an ex-Marine, so her coworkers rapidly learned not to try physical intimidation, lest they test the reliability of their group health insurance.)
In older buildings, a simple lack of capacity is the most common problem. These buildings were simply not designed to handle mass quantities of AC-powered devices. They also can’t handle the huge amount of interference generated and dumped back into the electrical system by the switching power supplies in PCs.
Surprisingly, even fairly new buildings sometimes run into capacity limitations. I have encountered situations in which, due to shortsightedness by the designers, some buildings built as late as 1993 aren’t equipped to handle a modern LAN environment. I can’t tell whether it is true ignorance, or simply a cost-cutting measure, but in the long run, it doesn’t matter.
For years, I have run into various power problems, often due to these capacity limitations, and had cured them with UPSs and, occasionally, power conditioners. In fact, I still remember the sound of the first wheezing PC I encountered. Due to massive voltage variations in a very old building, the fans of the PC and its companion external Bernoulli Box (removable disk system), would speed up and slow down in tune to the voltage fluctuations. It sounded like I needed to send it to a quit smoking clinic. Another dead giveaway of bad power was the monitor. It danced a jig that would have made Michael Flately proud.
Once I added a line conditioner (the client was in poor financial condition and couldn’t afford the extremely expensive UPSs of the day), the PC, B-Box, and monitor ran normally. The only minor problem left was the odd noise produced by the line conditioner. Every time it absorbed a large power surge, it would emit a loud, raspy growl. The client put this to good comedic effect when giving visitors a tour of the office by making sure that the guest stood only inches away from the line conditioner during the explanation of the computer system. When the line conditioner inevitably growled, the guest would invariably jump back as if attacked by an errant beast! In fact, when that client finally disappeared, I wondered whether it was due to a lawsuit instituted by the next of kin of a now-deceased guest with a heart condition.
My first encounter with totally intractable power problems occurred with a client who had solved the problem before my fist visit by installing a completely separate power system reserved for computers. One weekend, I was working alone on various upgrades and fixes. To make it more convenient to work on one PC, I moved it off a desk and onto the floor in the middle of the room. I had to move its surge suppressor to another socket to reach. When I turned the computer on, I found that it would only complete the boot-up sequence about one out of every three tries. Even when it did boot, it would randomly lock up without notice. It took a while for me to remember that there was a separate power system for computers. I had inadvertently plugged into a plain beige AC socket. When I switched to a red "clean power" socket, the computer functioned normally. (In case you’re wondering, I didn’t charge the client for my half-hour episode of stupidity!)
Next month I will continue with a spectacular example of power problems, along with various ways around them. Meanwhile, considering my comments about politicians, I’ll prepare my records for the arrival of the government auditor.
 

�1997, Wayne M. Krakau