On Thursday, March 10, 2011 10:25:58 AM RogerN did opine: > >----- Original Message ----- > >From: "andy pugh" <bodge...@gmail.com> > >To: "Enhanced Machine Controller (EMC)" > ><emc-users@lists.sourceforge.net> Sent: Thursday, March 10, 2011 4:59 > >AM > >Subject: Re: [Emc-users] Single Phase Lathe spindle motor question > > > >On 10 March 2011 01:24, gene heskett <ghesk...@wdtv.com> wrote: > >> But that was a 20HP motor, running on 235V 3 phase, and drew 39 > >> amps/phase > >> at rated power output. So a 100 HP motor would have needed only 195 > >> amps, not 330/phase. > > > >195A per phase on 3-phase input. Wouldn't it be 50% more on > >single-phase input? (Or would it be 3x as much?) > > 3-phase amps X 1.732 (SqRt of 3) = 3 phase amps (not dealing with > changes in power factor) > > Roger Neal
Wouldn't that be: 3-phase amps X 1.732 (SqRt of 3) = single phase amps? But then the supply would also be scaled, from the 240 range to 252 due to the lack of the vector additions the 120 degree phase angle causes in the 3 phase scenario. I'm confused enough without that. ;-) -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) <http://tinyurl.com/ddg5bz> War is never imperative. -- McCoy, "Balance of Terror", stardate 1709.2 ------------------------------------------------------------------------------ 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
