On Thu, 02 Dec 2010 19:54:01 -0800, Larry Jaques
wrote:


So, how much of this affects the generation of clean light in fluor
instances, generally on 120v single phase systems?


For all you ever wanted to know about power line harmonics, go to:
http://ewh.ieee.org/conf/tdc/elimina...t_Problems.pdf

The problem is also very real in single phase distribution systems
(120/240). The flourescent ballasts are electronic, just like the
computer power supplies referenced in the above-mentioned article.

The harmonics can be REALLY nasty.
Which is why, for computers (particularly servers and high power
workstations), I STRONGLY recommend DUAL CONVERSION UPS units - which
totally decouple the harmonics from the power line, and vise versa.

Power line harmonics are generated when a load draws a non-linear
current from a sinusoidal voltage. The harmonic component is an
element of a Fourier series which can be used to define any periodic
waveshape. The harmonic order or number is the integral number defined
by the ratio of the frequency of the harmonic to the fundamental
frequency (e.g., 150 Hz is the third harmonic of 50 Hz; n = 150/50). A
second harmonic is therefore two times the fundamental frequency of
the supply line volt current. If the supply voltage had been generated
by an ideal source (zero impedance), the current distortion would have
little effect on the supply voltage sine wave. However, because a
power system has a finite impedance, the current distortion caused by
a nonlinear load creates a corresponding voltage distortion in the
supply lines. This voltage distortion can subsequently disrupt
operation of other sensitive equipment connected to the same line.
Voltage distortion can also cause motors operating on the line to
overheat

Thanks, clare. That will certainly trump any answer I get from my
request about the subject in an email to Lithonia.