Balance is so important. We have balanced meals, balanced checkbooks, and balanced tires. We pride ourselves on laying out distribution panels such that we have balanced loads across the phases and a balanced appearance in the physical wiring.
Yet somewhere, we forget the idea of balance when we think of power quality and power availability.
Jean-Pierre Wolff, who will present another of his fine articles in the March issue, was a speaker at Electric 97. (I try not to miss his presentations-there or at NETA conferences). He made the point that we often take a myopic view of power problems and try to resolve them without considering the impact on the entire distribution system. Then, when things get worse, we shake our heads and say, "It's those harmonics." Maybe the next buzzword will be photon emissions. "We put in a harmonic trap and a K-rated transformer. The only thing that could be causing that nuisance trip is photon emissions." There's nothing wrong with harmonic traps or K-rated transformers. However, you don't blindly slap these into a distribution system because you "know" they mitigate harmonics. Their effects depend on the components they interact with.
In PQ Corner case histories, the "cure" is often a matter of going back to the basics. I could imagine Warren Lewis on site, asking for a one-line and not getting it. I could imagine Warren's grimace when he asks for preventive maintenance measurement histories and finds they don't exist. I worked in environments like that, too. Often the reason these things did not exist was "they cost too much."
I have seen people blame the manufacturers of power filters, when the installation was an ungrounded, conduit-as-the-neutral wye system. (They didn't pull a neutral wire to handle the unbalanced current, and yes, they did have 277V loads!) Those people took an unbalanced view. Rather than understand the system as a whole, they vainly forced a magic pill down its throat. And the problem simply would not swallow it.
The approach I suggest to you is one of balance. Some may call it a holistic approach. It may take more time up-front but it saves you an incredible amount of time later. That "later" time is the time in which production machinery should be running, instead of sitting without power or sitting because of damage from power quality problems. What I hear from consultants is how amazingly preventable these problems are.
Rather than think in terms of power quality or power availability, I suggest we think in terms of power assurance and keep all power problems within the same framework. Here's my prescription for doing that.
First, obtain or create all the documentation (electronic and paper) you need. This includes good working drawings. In an upcoming issue, you can read an article titled What makes a good working drawing? (Feel free to write to us with your ideas on this). Those drawings need to show how every component of the power distribution system relates to every other component. It also wouldn't hurt to have a database defining maintenance procedures and schedules. The software available to help you with drawings and databases is simpler to use and more powerful than ever.
Next, look at the electrical basics. For example, does the installation conform to Article 250? Yes, grounding and bonding are complex issues, but that doesn't mean you can ignore them. If you're unsure of the basics, you can search our website (www.ecmweb.com) for articles and learn those basics. Other resources include EC&M Books, IEEE, and the dozens of seminars put on by people like Mark Lautenschlager and Jean-Pierre Wolff.
Finally, look at ways to incorporate good design and workmanship into every place you see a piece of copper wire. If the wiring isn't neat enough to show the pride of the person who installed it, you can bet there are power quality problems. If the power wiring runs in the same wireway as the telecom, you can bet someone is going to have a problem with one or both.
The demands on our time and skill levels have never been greater, because the demands on our power distribution systems have never been greater.
I think we can rise to the challenge. Call me biased, but I say the people in this industry are a cut above average. Let's keep that edge.