The categories or labels used to describe the plethora of power quality phenomena that can occur on electrical systems have not changed much in the past decade or two. Measurement methods and acceptable limits for most systems have changed.
In attempting to explain to a colleague why we care about negative sequence components, I tried to follow the guidance that Bob Lawrie, another member of the NFPA 70B Electrical Equipment Maintenance committee, offered to me many years ago: never use a formula in an article.
Lightning is the biggest cause of damage and destruction of electrical and electronic equipment in industrial facilities, commercial buildings and homes, as stated in the 2008 report by the U.S. National Lightning Safety Institute.
The importance of monitoring the quality of the electrical supply has increased with the ongoing push to boost uptime, productivity and profits. When carrying out business 24/7, having a process or operational interruption can negatively affect of the bottom line.
While spaghetti adorned with one of the dozens of different sauces that are served in the small, off-the-beaten path restaurants in the Italian countryside is “splendido,” wiring that looks like spaghetti is just the opposite.
Once a year, I focus on the latest trends and changes in power-quality monitors, standards and mitigation equipment. This article initially focused on the latter, but after researching several dozen of the newer products on the market, one thing became apparent.
In this third part of my series on the most common power quality phenomena, I group several IEEE 1159 categories together under the general description of “distortion.” Though one might argue that all power quality phenomena result in distortions of the voltage sine wave, these are the more steady-s
Last month, we started the Top 10 in the power quality phenomena category with the most common disturbance: the rms variation. In second place are usually transients, those fleeting waveform changes that are far too brief to be seen by the naked eye in lighting.
From David Letterman to the FBI to Billboard magazine, the “Top 10” can be applied to just about any category, including power quality phenomena. Although it is a highly subjective process, there is some merit in being more than just familiar with them.
Reading through the websites and marketing Material of the major power quality instrument manufacturers in the hopes of figuring out which power quality monitor to buy can leave one feeling confused, frustrated and wondering which way to turn.
Debates within the organizations that develop the power quality standards will probably continue for years about why “power” isn’t really the subject of the standards. The majority of the standards present how to measure, monitor, characterize, categorize and set limits on voltage.
Not much time goes by without hearing, “My equipment used to work fine, but now it keeps locking up every so often. Our productivity is suffering big time.” My usual first questions are, “What has changed, and what are you doing differently?” The answer is usually “nothing” for both.