View Full Version : VFD for 5 hp motor; recommendation wanted...

03-10-2008, 11:01 PM
I need a 5 hp 240V VFD w/ single phase input... anyone have a brand with which they're really happy?

- Bart

03-10-2008, 11:43 PM
I have dealt with Hitachi,Allen Bradley,Teco and Automation Direct.

Of them Hitachi and AD are my favorites with AD edging ahead of Hitachi in terms of price/ease of setup.YMMV

03-10-2008, 11:55 PM
I also have used all of the above mentioned drives and also prefer Automation Direct for price, ease of setup, and bang for the buck. The AD drives in the 240 volt 5 Hp range are not specifically rated for single phase input but you can use them that way with a little de-rating. I would think a 7 1/2 Hp drive would be good for a machine tool application HOWEVER, give AD a call and their tech support people will be able to give you the right answer for this application. You are always better off getting those types of answers from the factory people.

Also, search the archives, this has been discussed quite a lot before and there is good information there.

Good luck,

03-11-2008, 01:17 AM
I called Allen Bradley about one for my 5hp motor, asked the same questions. Basically, for relatively soft start and generally less than full load (lathe using VFD soft start, mill, grinder, etc.) then for single phase input, go for 1.5* motor rating. For hard start or full power use (compressors, etc) go 2*. Unfortunately, in those ranges, they tend to be quite pricey and require large external NEMA inclosure's, particularly large if sealed.

03-11-2008, 11:08 AM
Thanks, guys! I really like the VFD on my BP, but the larger ones are indeed
significantly more expensive. The existing maze of contactors, etc, on my
lathe is on the fritz, and the previous owners spent $$ chasing the problem
w/o success. The motor is known to work (spins when contactors are
closed manually) so I'm going to replace all the f/r and stop logic w/ a VFD; that way I won't need a rotary converter either.. The AutomationDirect manuals are nice and clear, and getting the logic right doesn't look like a problem.

- Bart