On Mon, 2011-03-14 at 15:41 +0000, andy pugh wrote: > On 14 March 2011 15:30, gene heskett <ghesk...@wdtv.com> wrote: > > > If I read it right, it is being said that perhaps a capacitor of the > > correct value to create a usable phase lead, from L1 or L2 to L3, will > > start a 3 phase motor on single phase power, direction of the rotation > > dependent on which 2 the capacitor is connected to. > > Yes, in fact this is how my coolant pump is wired. You don't get the > same power output, and the motor needs to have an external star point > so that it can be wired for the lower voltage, but it works fine. > > In fact, many of the cheaper single phase motors are exactly that, a > three-phase motor and permanently connected capacitor, with no > centrifugal switch. > I don't know if it is still the case, but the single-phase motor we > bought from Machine Mart was exactly this, and had far too little > starting torque for the vehicle lift we wanted to run. > http://www.machinemart.co.uk/shop/range/details/230v-110v-single-phase-motors/path/single-phase-electric-motors
My home built 5 Hp converter uses a ~240 uF starting cap and much less than that on the legs. If you really want it right you adjust the caps to get the voltage on the third leg correct. Pretty easy even without the mathematical analysis. Some things can be done just by trial and error; usually more error than trial. ;-) Copying someone else's example helps a lot, at least to get started. Dave > ------------------------------------------------------------------------------ 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
