With the unprecedented amount of unregulated information available on the internet, one can find a wealth of facts and fiction on a given subject. Power quality is no exception. Even those skilled in the art can be misled by...
During a recent summer thunderstorm, I was looking out the living room window when a blinding white light flashed accompanied by a deafening, crackling bang. I didn’t need a power quality monitor to know what that was, nor...
Last month, I reduced the vast array of phenomena that create power quality problems to the four most common categories and a set of causes-and-effects within those categories. Now, I solve them. An important step to remember...
The key to any detective show is to quickly find out who did it. For power quality problems that take down the process in a facility, whether it is plastic extrusion, financial data exchange or the lights in an indoor stadium...
While reviewing the various types of power quality disturbances I’ve previously covered as well as the phenomena PQ standards frequently reference, one of them stood out. Harmonics, sags and swells, transients, interruptions,...
In the past 12 months, I have celebrated two career milestones. It has been 40 years since I began working as a junior development engineer, being the fifth engineer hired at Dranetz Engineering Laboratories when it was on...
Though Ohm’s Law is a generalized construct that is not as encompassing as Maxwell’s Equations, it is far more understood and used by those in the electricity business. We have used Ohm’s and Kirchhoff’s Laws to understand...
When I first became involved with the IEEE working groups on power-quality standards in 1994, IEEE had just published 519 1992, Recommended Practice and Requirements for Harmonic Control in Electric Power Systems. (The next...
While researching for new information about sags, I found the first reference on Google search to be familiar. It was a paper, “Sags and Swells,” that I wrote in 1994 for the NFPA 70B Technical Committee on Electrical...
At a small telecommunications facility, equipment mysteriously started self-destructing for no apparent reason. Laptops, routers, printers and cell phones were apparently just becoming nonfunctional. The facility operator’s...
When a customer complained about the lights flickering in the past, it was difficult to get a quantitative measure of the problem. The parameter, Pst (perceptibility short term), specified in IEC Std 61000-4-15 and eventually...
In the August issue, I reviewed some common power-quality related issues, including insulation failures on a motor’s outer windings, unexplained offline trips of adjustable speed drives, blown fuses on surge suppression...
