Igor Chudov wrote: > On Tue, Mar 8, 2011 at 1:12 PM, Kirk Wallace > <kwall...@wallacecompany.com>wrote: > > >> Another thing is that for all static and rotary converters I have seen, >> the single phase is passed right through and the converter creates a 90 >> (or 270) degree phase, so you get 0, 90 and 180 degrees instead of 0, >> 120 and 240 degrees. A three phase motor should run more smoothly with >> evenly spaced phases, but on the other hand, I haven't noticed any >> problem with my lathe that uses the converter. >> >> >> > This is not true, phases are evenly spaced on mine. I use run capacitors. My > voltages are very close to each other L1-L2, L1-L3, L2-L3. > > Right. Although the generated leg is at a right angle to the other legs, it is added at the CENTER tap of the 220 V mains. It just so happens if you work out the trig, it DOES produce the right phase relationship. If you draw an isoceles triangle, the base is the 220 V mains, the center of that is your neutral. The generated leg is 207 V from the neutral to the peak of the triangle. If you find the center between the three vertices, each vertex will be at a 120 degree angle. The trick is the center-point voltage in this system is not at neutral, as it would be in a 120/208 Wye system.
You really HAVE to draw this out on paper to understand it. Jon ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
