----- Original Message ----- From: "gene heskett" <ghesk...@wdtv.com> To: <emc-users@lists.sourceforge.net> Sent: Thursday, March 10, 2011 9:30 AM Subject: Re: [Emc-users] Single Phase Lathe spindle motor question
> 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 Oops, yeah, I meant single phase. I believe the formula for electrical horsepower would be something like volts X amps (X 1.732 for 3 phase)X power factor X efficiency / 746. Roger Neal ------------------------------------------------------------------------------ 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
