For what it's worth, I have a lathe with a 7.5HP motor and used a 10HP Hitachi VFD like this:
http://www.driveswarehouse.com/Drives/AC+Drives/Variable+Torque+VFD/X200-075LFU.html?osCsid=04e47b5d74f9275e98232b165be36c89 The Hitachi website gives directions on using the larger drives with single phase input. You are supposed to upsize the drive by 1.732 but I went with 10HP because I figured it would do what I needed, drives are generally rated for 1.5 X rated for a limited time. The weak link is the input rectifiers, you have to get all the amps in through single phase, that's where the 1.732 comes from. So far I haven't been able to push it hard enough to have any problems. One time I let the lathe just idle, not cutting anything, the VFD showed 13A 3 phase to the motor, the input to the drive was ~5A single phase, the VFD handles the power factor problems and draws closer to true power from the line. Roger Neal ----- Original Message ----- From: "Clint Washburn" <cl...@clintandheidi.com> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Sent: Tuesday, March 08, 2011 7:18 PM Subject: Re: [Emc-users] Single Phase Lathe spindle motor question > Ted, > > What kind of motor did you go with and what model of vfd do you use? Also > I have not yet purchased a drive yet I am weighing my options. I am > thinking of 5-7.5 hp. With the price some of the vfds are going for I > would pay several times over what I paid for the lathe. > > Thanks, > Clint > > On Mar 8, 2011, at 8:54 AM, Ted Hyde <laser...@gmail.com> wrote: > >> emc-users-requ...@lists.sourceforge.net wrote: >>> Message: 5 >>> Date: Mon, 7 Mar 2011 22:03:45 -0800 >>> From: "Clint Washburn"<cl...@clintandheidi.com> >>> Subject: [Emc-users] Single Phase Lathe spindle motor question >>> To: "'Enhanced Machine Controller \(EMC\)'" >>> <emc-users@lists.sourceforge.net> >>> Message-ID:<00bd01cbdd56$99811290$cc8337b0$@com> >>> Content-Type: text/plain; charset="us-ascii" >>> >>> I am in the process of converting my 1978 Hitachi Seiki CNC lathe to >>> EMC. >>> It currently has a 7.5 KW dc motor that used to be powered by FUJI SCR >>> drive. My first problem my house does not have 3 phase power. I am >>> having >>> to work around this issue with my whole retrofit. I wish to convert >>> this to >>> a 3 phase AC spindle. What VFD's are people having success with as a >>> spindle drive with single phase power? Is it realistic to have a 10 hp >>> 3 >>> phase spindle on single phase power? or will I have to go with a >>> spindle >>> motor closer to around 7.5hp instead? What is everyone's input on this? >>> >>> Clint Washburn >>> >> Clint - I converted my Tsugami lathe (also 7.5Hp DC spindle) over to a >> 5hp AC spindle - and for testing was running on single phase 220. My AB >> VFD would only get the motor up to about 70% speed (2200rpm) before >> going into Bus Undervolt Fault - I was running this directly from the >> front panel of the VFD without EMC intervention at the time, so there >> should have been little to no regen or accel/decel problems. The spindle >> was also under no load (from cutting) - so under a cut scenario, I'd >> expect the unit to fault just as soon as the insert entered the cut. The >> unit functions just fine under 3phase power, of course. >> It may be worthwhile to note that although many VFDs with 3 phase input >> are built on a simple bridge-cap system, how they check the line-line >> voltage may differ, so going leg R-T instead of R-S (for example) may >> get you lucky. Alternatively, you may look at a separate DC supply, and >> feed the ?440 into the DC bus input on your VFD....assuming your VFD >> supports it. I can do this on my AB, apparently. I recall Rexroth >> (Bosch) did this with a lot of their high end servo and spindle drives, >> so did Mitsu - one central DC supply, with drives that connected to the >> buss, instead of all AC input units. >> My instinct based only one one experience says you're going to have a >> challenge getting that 10hp spooled up on single phase. >> >> BTW - where did you get a 208vac 10hp drive? By the time you get higher >> than 5hp, most are wanting 380-480 input....or you have to mortgage the >> house..... :-) >> >> Best wishes, >> Ted. >> >> ------------------------------------------------------------------------------ >> 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 ------------------------------------------------------------------------------ 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
