Trumpy (and others),
There is a lot of bad teaching going round regarding harmonics. One of them is "harmonics are created" by the likes of SMPSs etc. If harmonics were 'created', don't you think some smart alec would have found out how to take that energy and power the computer with it by now?
It is far better to say that the waveform of an SMPS has a "high harmonic content".
As for "only on Neutral". This has been confused with running many such devices in a 3-phase system. The Live and Neutral carry the same current waveform so are therefore subjected to the same harmonic content. When placed in a 3-phase system, then Neutral is then subjected to the sum of the harmonics of all three phases - in some instances the sum causes cancellation, in others, addition (read up on triple-n - or 'triplen' as it is now called - harmonics, but also be warned about the bad teaching that says "all triplens add on the Neutral"!).
Also, strangely enough, the heavier you load the SPMS, the lower the relative harmonic content (not amount, as this is relative to the current drawn, but content as a percentage).
PDH,
You will most certainly rid the Neutral of harmonics running your hi-tech load L-L, but you're going to increase the harmonic content on the phases. However, I do believe the total harmonic content on the supply side of the transformer will be reduced as you're creating 6-pulse rectification. I'd be very interested in your results.
M.
[This message has been edited by marcspages (edited 02-21-2005).]
