Check out this place. Good prices on drives and motors. On Mon, Jan 1, 2018 at 11:46 AM, John Figie <zephyr9...@gmail.com> wrote:
> All, > > Thanks for your replies. > > My real question was to see if anyone had used GOHZ or some other cheap > drive. I currently run all my machines from a home made rotary phase > converter. It works pretty well but does not produce the best 3 phase. > Yes I know you can use capacitors to adjust the outputs which I have. The > rotary converter has been running in my shop for about 15 years. I have a > hydraulic automatic surface grinder that does n't like being run from the > phase converter. The pump motor overheats when run from my rotary > converter, I think maybe this is because the motor runs near full load. > > I know I can use a larger drive and derate it to use on single phase power, > but that seems like a much more expensive option. Some drives have missing > phase detection that I could probably trick with some kind of AC input. I > think the concerns for me are that the input diode bridge will see the > input current distributed among 4 diodes but instead of 6. Also the > conduction angle of the diodes will be longer since all of the input > current must be supplied from the single phase rather than overlapping > phases. Finally the stress on the DC bus capacitors will be much higher due > to the higher DC bus ripple. This bus capacitor RMS ripple current degrades > the capacitors due to internal heating. > > Now since this is a lathe spindle and I am a hobbyist how often will I > really need to load the machine to 5hp? Probably not very often. Also I can > set the acceleration/deceleration to a conservative value to reduce the > peak currents. Additionally I think I could replace my rotary phase > converter (which is kind of noisy) with the VFD which will produce a > different kind of noise (electrical) but It will be quiet. > > My motivation for asking about GOHZ is that I just discovered them and they > have a $294 drive rated for single phase input so I would presume that the > additional stress was considered in the design. > > Automation direct does not list any VFDs of 5hp or higher rated for > operation from a single phase. > > Here is what I have found so far listed on a spreadsheet. > https://docs.google.com/spreadsheets/d/1YS-QKbJIlBYDSPdWAelA6ZF0zbS30HrHn > qE02-opSRI/edit?usp=sharing > > If anyone knows of other options please let me know. > > John Figie > > On Mon, Jan 1, 2018 at 11:09 AM, Dave Cole <linuxcncro...@gmail.com> > wrote: > > > I have heard that sometimes you can get around that by putting a motor > > run capacitor between one of the live phases and the unconnected input > > power terminal. > > That can sometimes trick the drive into thinking that it has power at all > > of the terminals. > > > > Back when VFDs were very expensive the way to do this was with a static > or > > rotary phase converter. > > I have a 5 hp 3 phase motor on an old turret lathe spindle that I run off > > a rotary phase converter that I put together a long time ago. It > > works. You can find how to instructions on how to build one on the > > net. You will need a 3 to 10 hp 3 phase motor as a base device for the > > converter. > > > > You can also make a static 3 phase adapter for your existing motor simply > > by adding some capacitors to "power" the third phase. Info for that is > > also on the net. > > > > Dave > > > > > > On 1/1/2018 3:46 AM, Nicklas Karlsson wrote: > > > >> Usually there is a diode rectifier at the input but I guess they also > >> measure voltage and refuse to run then to low so experience is > important. > >> > >> On Sun, 31 Dec 2017 18:45:44 -0600 > >> John Figie <zephyr9...@gmail.com> wrote: > >> > >> I have a 5 hp 240V 3 phase induction motor that is for a lathe > spindle. I > >>> only have single phase 240V power. It seems that most 5 hp vfds do not > >>> allow single phase input. I found this: http://www.gohz.com/5hp-vfd > >>> Does anyone have experience with GOHZ or other affordable 5 hp drives > >>> that > >>> will run on single phase? > >>> > >>> John Figie > >>> ------------------------------------------------------------ > >>> ------------------ > >>> Check out the vibrant tech community on one of the world's most > >>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot > >>> _______________________________________________ > >>> Emc-users mailing list > >>> Emc-users@lists.sourceforge.net > >>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>> > >> ------------------------------------------------------------ > >> ------------------ > >> Check out the vibrant tech community on one of the world's most > >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > ------------------------------------------------------------ > > ------------------ > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- "Anyone who believes exponential growth can go on forever in a finite world is either a madman or an economist." -Kenneth Boulding, economist Corporations are NOT people and money is NOT speech! ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
