[NIC 77]

That 25a output will be for 380v. It should be enough to run anything that could be run safely on a 50amp 240v 1ph residential outlet.

I almost misunderstood you there, and was about to tell you that you can't get 25 Amps 3 phase 380V from 240V 1 phase 50 Amps, but then I realized what you were saying.

Have you seen other VFDs with 220v in and 380v out? I couldn't find any when I last looked.

Yep. Lots. Search for 220V to 380V VFD on Aliexpress. There are lots. Also the one you linked to is only 300 Hz.

I see the value of these things as having the flexibility to buy some of the 380v Colombo used spindles. You rarely ever see a good deal on a used 220v ATC spindle but used 380v spindles are worthless. Anyone that could use one would probably buy new gear.... until now...

Some of those spindles have the option of being connected in Star or Delta, which means that you can rewire them to 220V by switching a few of the connections. Some don't.

The monster I have is 380V, but I plan to run it on 220V instead of limiting the Amps. I did a thread about it on practical machinist.

The Voltage / frequency is constant (straight line at an angle, ie: constant slope) up to a point, so at lower RPM's you are not operating at 380V. Depending on what the power vs speed curve is for the spindle, you would never even notice you were limited to 220V for a large part of the speed range.

I'd like one of those 220 / 240V to 380V VFD's but would still limit it to 220V output so I could get more amps, because I'd rather run it at normal amps and a lower voltage for part of the speed range. Truth is I'll buy something used and cheap most likely, still haven't bought one.

if you buy more 400 volt capacitors, you can run a 480v vfd, such as early AB 1305 drives, on 240v single phase by connecting one line to all three of the three phase input at the terminal block, and the other to the center of the two (or 4, or 6, 8, etc) 400v capacitors (which are connected in series for 800 volts) this is the same method used for almost all power supplies that have a single switch to convert from 120 to 240v operation.. you can either de rate the vfd or buy more capacitors.

i have heard someone has been doing this modification and selling them on ebay, and i've done it myself with an older AB 1305 drive. if you have three phase i believe you can connect one phase to the midpoint of the capacitors and the other two phases to the terminal block and you will probably not have to derate the drive much.. but i don't have three phase to experiment with at the moment.

Not sure I understand what you're saying. But I'm interested to learn more. Do you know of any videos or step by step examples of this procedure?

What kind of output voltage range can you select on your 480V VFD? I assume you can enter any points on a V/f curve from 0-480? So at lower voltages the power draw from the outlet is less for the same amps.

For someone like myself, who wants to run at 220 / 240 V max output voltage from the VFD with 240V single phase input (so that I can keep the available output amps up) can I modify a 480V VFD to get what I want? I ask because I may be able to pick one up cheap, and that would help me out. I also plan on using the VFD to do the phase conversion, I understand that this means you have to overspec the input current for the VFD unless it specifically states it's a 1 to 3 phase VFD.

I'd appreciate any additional info you could provide on what you did.