On Sunday 31 December 2017 19:45:44 John Figie wrote: > I have a 5 hp 240V 3 phase induction motor that is for a lathe > spindle. I only have single phase 240V power.
1, here in the us, 240 will actually measure about 254 as its 2 legs of nominally 127 volts. 2, most vfd's are if derated, tolerant of single phase power, and are often labeled for both uses. But because that seriously ups the AC currents flowing in its input AC to DC convertors, it can effect the life of those parts, so expect to have to replace then at scheduled intervals for best dependability. Your 5 hp will need its 7.5 rated vfd to have its own circuit, which will need to be wired in 8ga range wire or bigger, and a correspondingly big circuit breaker. Possibly a 40 amp breaker. I have a 1.5 horse rated vfd, running a 1 hp 3 phase motor 230 volt motor on a 10 gauge circuit with a dual linked 20 amp breaker, and have had no nuisance trips, or complaints from the vfd even under locked rotor conditions. YMMV of course, but these should be a decent starting point. I don't have a power switch for it, but use a couple 40 amp rated SSR's driven from the pi that runs the lathe when LinuxCNC has been enabled. That brings up all motor power at the same time and has been working well for about a year. > 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? See above, and look for a 7.5 hp rated vfd. It should/will be far more dependable when fed with single phase power. > > 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 > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
