Don
I did have a much smaller power quality problem that I traced to the same two villains at the Integrated Power Corporation Plant in Frederick, Maryland during the early nineties. The two villains I am referring to are disparate grounds and triplen harmonics.
The disparate grounds were at the electrical and telephone entry points. In spite of the fact that both grounds had been lugged to the building steel I could measure a difference of over twenty volts between the two grounds and the plant was suffering telephone equipment failures. Once I bonded the two grounding points together with a copper conductor that was big enough to be the GEC for the building service the voltage went to zero and the telephone equipment failures ceased.
The triplen harmonic problem was limited to branch circuits serving research work stations. The loads were computers, inverters under development and laboratory test equipment. By using both Fluke and Tektronics test equipment I was able to demonstrate to the companies Electrical Engineers that there were substantial measurable harmonic currents in the bench branch circuits. The total of those currents did not seem to cause any overheating of the panels or transformers but it did cause excessive voltage drop on a few research bench branch circuits. By running separate branch circuits in type MC cable for those outlets and upping the wire size one gage the problems went away. The problems they were having were unstable test equipment because of high noise levels on the grounds and breakers opening on overload while supplying inverters under test. No change was made in the breakers. I didn't install isolated grounds even though they were all the rage at the time.
--
Tom Horne
