Kirk, "Neutral" is not to be considered. You have two wires coming from the supplier. Adding a capacitor makes three of them. The two mains lines are 180 degrees apart by definition. The capacitor makes a third phase 90 degrees between them. Connect your motor, and it will be running, regardless of which line is grounded.
Peter Blodow Kirk Wallace schrieb: > On Mon, 2011-03-14 at 17:58 +0100, Peter Blodow wrote: > ... snip > >> A capacitor connected to one leg of the two-phase system produces a 90 >> degree phase shift relative to this lead. Using this as a mock three >> phase system, you will have 180 + 90 +90 degrees for a revolution >> including a direction information, depending to which leg you connected >> the capacitor. The distribution is uneven which is the reason for >> reduced power, but better than nothing. Don't confuse this with a >> starter capacitor used to supply a direction information to a generic >> two phase motor! Those are for short time use with small motors only and >> blow their tops when used continously (because of faulty starter relay >> or so). >> > > In case my attachment doesn't go through, here is my graphical study of > a rotary three phase converter: > http://www.wallacecompany.com/machine_shop/EMC2/three_phase_converter-1a.png > > The 180 degree voltage phase shift is only an issue if neutral is used, > but it is not. I think the decrease in efficiency is due to using one > phase to try to generate two more and the currents are much higher than > normal. (Viva VFD's) > > > ------------------------------------------------------------------------------ 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
