On Tue, Mar 8, 2011 at 4:43 PM, Kirk Wallace <kwall...@wallacecompany.com>wrote:
> On Tue, 2011-03-08 at 16:07 -0600, Igor Chudov wrote: > > On Tue, Mar 8, 2011 at 4:03 PM, Kirk Wallace < > kwall...@wallacecompany.com>wrote: > > > > > On Tue, 2011-03-08 at 15:35 -0600, Igor Chudov wrote: > > > ... snip > > > > You can only have equal voltages l1-l3, l2-l3, l1-l2, at 120 degree > phase > > > > angles. > > > > > > With 0, 90, 180, if the L3 peak to peak is higher than L1-L2, then the > > > L1-L3 and L2-L3 could be made to equal L1-L2. I seem to recall that the > > > converter capacitor size adjusts this, but the phase angle spacing will > > > still be the same. > > > -- > > > > > > Capacitors do adjust phase angle. > > > > i > > But there is no getting around the fact L1 and L2 are 180 degrees apart. > Kirk, it is not true. You cannot even say, taking two points, that they are so many degrees apart. you need a third point for this statement to even make sense. if line neutral is that third point, then yes, L1 and L2 are 180 degrees apart. But a three phase motor does not even see the line neutral, so it is not relevant. Think about it. i > The phase and voltage of the converter's L3 is unanswered. One of my > problems is that I have never tried to verify any of this with an > oscilloscope. I only have two channels and they are referenced to > ground. Making a test seems like it would take some effort and > converters generally work fine in practice, so the motivation isn't high > enough yet. Thinking more, its just a matter of hooking up the probes to > L1 and L3 and seeing what the phase shift is. If I leave the probes > unconnected, there is no danger to the scope. Besides the converter > should have the same ground. Maybe. > -- > Kirk Wallace > http://www.wallacecompany.com/machine_shop/ > http://www.wallacecompany.com/E45/index.html > California, USA > > > > ------------------------------------------------------------------------------ > What You Don't Know About Data Connectivity CAN Hurt You > This paper provides an overview of data connectivity, details > its effect on application quality, and explores various alternative > solutions. http://p.sf.net/sfu/progress-d2d > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ 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
