I'm not understanding how the transformer is connected into the distribution to result in the 9PC's over 3 phases then 15PC over 3 phases. Are you suggesting a isolation transformer serving a subpanel for the 15 PC's?
I haven't done the FFT on the input to a PC's switchmode power supply, but I believe that the entire draw is not at 180 hz relative to the nominal 60hz. Even if it was only drawing 180hz (and other triplens), I thought when you add the triplens, you can theoretically get a max of 1.73 times the phase current on the neutral. I will try to draw three phases of 180hz, 120 degrees out of phase from each other and see what I get.
[This message has been edited by Ron (edited 10-13-2005).]
