Don,
That is not correct. The phase displacement of the harmonics is equal to the phase displacement of the fundamental multiplied by the harmonic order.
In three phase systems, you take a fundamental phase displacement of 120 degrees, and any triplen harmonic will produce a phase displacement that is a multiple of 360 degrees.
In single phase systems, _even_ harmonics will take the phase displacement of 180 degrees in the fundamental, and produce a phase displacement of that is a multiple of 360 degrees, or _0_ degrees. As far as I know, people have not been seeing even order harmonics as a problem, they do, however exist.
-Jon
