View Full Version : Which VFDs can run 1 phase in / 3 phase out

06-21-2010, 11:56 PM
Not too serious just toying with the idea. Can anyone recommend a 240 single phase input / 208 / 3 phase output - 5 Hp VFD

06-22-2010, 12:11 AM
Only one I have done personally was a Teco 10HP 230v 3~ input derated to 5HP with a 1~ input.That was on a wood planer a friend of mine bought and he happened on a VFD used on Ebay for $200.

I haven't tried one yet,but a buddy at one of the local plants swears by these-


Hyaundi made in Korea

J Tiers
06-22-2010, 12:16 AM
Invertek, which is also re-branded as several other brand names, have drives that do 1 phase in 3 out with no derating.

They also have regular 3 phase in/out, and single phase in/out.

One of the drive sources is closing out a bunch of TB woods stuff, some of which is rebranded Invertek product. I don't know if any of it is 1 in 3 out, but there are some screamin deals.

You could afford to get a 2x larger drive as a derate, and still save money.

Forrest Addy
06-22-2010, 01:13 AM
My experience is (installed about 30 over the years) that all VFD's can be run from single phase. There are VFD's designed for single phase (typically 3 HP and below) and three phase without de-rating. You may need to de-rate if the VFD in question is rated for three phase only.

How much to de-rate requires an assessment of the specfic application. You have to estimate the motor's duty cycle (manual machine tools about 20%; pumps and compressors about 95%)and set the various parameters with a little care. Many machine tools never see full load operation unless they are used in real production so re-rating mey not be neessary. Some would point to the motor's full load Amps as though that was a defining characteristic. Not really for the home and small connercial job shop, unless you run the motor to full ratings. If you set the "accel" to 3 seconds or more and the inertia of the connected load is typical for an engine lathe, the starting "surge" may not even ramp to FLA.

Another point is, some VFD's have a feature called "missing leg fault" or "phase out fault" to prevent operation should one leg of the three phase poop out. If so there will likely be (not 100% sure) a parameter setting to defeat or enable this. You might see this feature on drives 50 HP and larger.

I'm currently working on a replacement drive on my engine lathe. The logic board died on the 10 HP drive I had and I lucked into a fairly recent GE/Fuji 300AF 10 HP made Dec 2003 with 305 hours on it. I'll be running a 10 HP motor; I looked up the load components ratings in the manual, worked the math, and concluded the drive didn't need to be derated at all for my application. The input diodes are rated for 75 Amps and the IGFET's on the output are rated for 50 Amps. The drive itself is rated for 33 Amps and the motor 27 Amps. Work the math and the drive will run within component ratings at full load motor Amps without exceeding component ratings - except for the filter cap.

There's over double the ripple current in a filter cap for single phase compared to three phase. It needs a choke in the DC buss but the drive is made for this mod. There's a pair of jumpered terminals for a choke right there. The secondary of a 10 KVA dstribution transformer connected for 115 volts will be just about right for a choke but not ideal. There are refinements to consider but as a quick and dirty choke it will serve to mellow the ripple before the cap has to be deal with it.

Sorry, Joe. I kinda went off on my own rant there but maybe you can draw lessons from them.

Edited to remove faux pas.

06-22-2010, 02:01 AM
SEW-Eurodrive are very nice VFDs with excellent product support. http://www.sew-eurodrive.com/

Using a VFD to run a 3 phase motor from a single phase supply is a very common application.


J Tiers
06-22-2010, 09:35 AM
A number of the SEW drives are re-labeled Invertek drives, supplied to SEW on OEM program......

My experience is (intalled about 30 over the years) that all VFD's can be run from single phase but with de-rating - no exceptions.

Forrest, Some drives are MADE for the purpose, and any needed derate of the input diodes and bus capacitors is inherent in the design.

06-22-2010, 09:38 AM
Forrest, Some drives are MADE for the purpose, and any needed derate of the input diodes and bus capacitors is inherent in the design.

And some drives specify which terminals to use with a single phase supply because they are the ones with uprated diodes.

06-23-2010, 06:53 PM
mitisubishi z024

06-23-2010, 08:14 PM
I have an ABB drive running my lathe. Very nice unit.