The owner of a single-family Cape-Cod-style home complained of lights blinking off and on for six months. It occurred mainly at night, seemingly in half the house. Stormy nights might have made it worse. It was annoying...
My February column was about looking for the obvious when troubleshooting power quality problems. At one of this week’s jobs, I should have followed my own advice. This job was one of those mentioned in that article: it began...
One possible explanation to last month’s mystery as to why the lights in one bedroom became brighter when the other room’s lights got dimmer was a voltage unbalance. (“Unbalance” is the commonly used term, although most...
In previous articles, I have covered typical troubleshooting case studies, including sags caused by large- horsepower motors and heating elements, oscillatory transients caused by power-factor capacitor switching, destruction...
movies titles with numbers reverberate in my head: ”The Magnificent Seven,” “12 Angry Men,” “Catch-22” and “The Dirty Dozen.” The power quality realm features a dirty half-dozen: the six most common PQ phenomena result in the...
Some power quality (PQ) potential problems have very few outwardly detectable signs. Voltage sags are called blinks in some trouble reports as the lights have a noticeable change in intensity, as does voltage fluctuations...
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...
In my 40-plus years in the industry, I have analyzed customers’ power quality monitor data files and heard their stories about hundreds of things that have happened in their facilities or homes: some mysterious, some...
