On Thu, 2008-07-03 at 21:08 -0400, John Kasunich wrote: ... snip > capacitor, you can run on single phase. There will be significantly > more ripple voltage on the capacitor (which may affect downstream > circuitry), and significantly more ripple current through the capacitor > (which may increase heating and shorten its life). Reducing the load > will reduce both of those effects... if you are running at half the > design load or less you should be perfectly OK.
I was wondering if one could rectify and filter the single phase voltage and feed this into the VFD. Maybe with DC on R, S and T or L1, L2 and DC on R, S and T, respectively. This might allow the VFD to run at its rated performance. Another option might be running the VFD on a rotary converter. > Some small (low HP) VFDs have the diodes and capacitors sized for single > phase input - you'll have to study manuals or datasheets to see if that > is true for yours. > > Minor nitpick: it's called single phase, not two phase. Yes, there are > two wires, but they are 180 degrees apart, which means they are really > the supply and return of a single phase. Three phase has three lines > that are 120 degrees apart. There are "two-phase" power systems, with > either three or four wires making two circuits that are 90 degrees > apart, but they are _extremely_ rare. > > Regards, > > John Kasunich Rotary converters might be considered two phase, they pass each single phase leg (180 degrees apart) and create a "third" phase, 90 degrees away from the singe phases. Mine seems to work okay, but it's not really three phase. -- Kirk Wallace (California, USA http://www.wallacecompany.com/machine_shop/ Hardinge HNC/EMC CNC lathe, Bridgeport mill conversion, doing XY now, Zubal lathe conversion pending Craftsman AA 109 restoration Shizuoka ST-N/EMC CNC) ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
