On Tue, Nov 3, 2015 at 10:02 AM, John Kasunich <jmkasun...@fastmail.fm> wrote:
> But of course the speed will be lower. For example, if it is designed for > 380V, 240Hz, 14,400RPM, > the volts-per-hertz ratio is 380/244 = 1.5833. If the VFD can only > deliver 208V, then you will be > limited to 208/1.5833 = 131Hz, and the top speed will be 7860 RPM. It > will still deliver rated torque > at rated current, but since the speed is lower the kW will be lower - only > about 3.8kW. > It's not my specialty so I am trying to go over the numbers methodically---please check if I am getting it right. At nominal 380V the thing runs at 6kW6kW * 208/380 and 60*240 Hz, i.e. 14400 rpm. At 208V it should do 208/380*14400, or 7880 rpm, close enough. But for power, P=omega*T, 6kW * 208/380, or 3.28 kW. amirite? ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
