Help choosing Siemens VFD for HMS :)

I need to go from 220v 1 phase in my shop to 220v 3ph to power the following motor:

Reliance Electric
3/4hp, 220v, 3ph
NEMA 56 frame
1725 @ 60Hz
Reversible, continuous duty

Looking to do it with a VFD for flexibility reasons as opposed to a static converter. It should be a Siemens drive b/c I can get that brand at cost through work.

Can anyone help out? Looking for something easy and not too complex for my HMS application, as I'm a VFD neophyte

The application is a South Bend 9A lathe. Hoping to use the original control switch to run the VFD control circuitry, my lathe has push-button control as opposed to a drum switch, if that matters.

Get a 1hp VFD that is 1ph input rated.


If you can wire up a motor and a switch, then installing a VFD should be no problem. VFD's are almost an appliance device.

VFD prices can vary a lot. Spend no more than about $120 for a 1hp VFD for your lathe.

That much I already knew I'm just having a bear of a time which Siemens VFD meets those specs - most on the website are not user-friendly described

I get it now.

The Siemens GS1-21PO is a 1hp single phase input 1hp VFD.
The Siemens GS2-21PO would also be another logical choice as it is a 1hp 1ph input vfd.

Even though I now work for Siemens, to be honest we don't really play well in this sandbox.

What you want is a Sinamics G110 drive. It is the easiest to use and goes up to about 4HP for 1 ph input. The .75HP unit is a part #6SL3211-0AB15-5UA1, but then you have to order the operator panel separately (that's why I say we don't play well). It is not a vector drive, so slow speed torque will be an issue if you need to do that with it.
http://www.automation.siemens.com/sd/sinamicsg110

If you need high torque and/or more precision at slow speeds, you need the Sinamics G120 drive, but it is not designed for 1 ph input without de-rating, so you would need to buy a 1.5HP drive (and the operator panel again). To be honest, you can probably do better with a Teco or Hitachi drive at that point.