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VFD questions??

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  • VFD questions??

    Yes I have searched and did read a number of posts.

    I have been running my current mill on a static phase converter without issue for 5 years but I just sold that machine and I am replacing it with a new to me 3 HP 3пи CNC mill (control and coolant pump is 110V). I could just run it like the old one but I think I would like to try a VFD.

    I use a VFD on my CNC router but it came with the 3 HP 24000 RPM Columbo spindle and was setup for that spindle by Columbo when I ordered it.

    What brand is a good one to get?

    Do you size a 3 HP for a 3 HP VFD when you are converting 220V single phase to 220V 3 phase or does the VFD need to be bigger? If I remember right when I bought the spindle & VFD for the router they sized the VFD bigger because of the single phase input.

    The rated spindle speed on the new CNC mill is 4200 RPM can I run that motor faster with the VFD and if so what would be the speed I should max out at?

    I don't know much about the VFD I have now I just know how it works on my spindle and I don't think it has any braking when I turn the motor off it coasts to a stop. When I turn the VFD on I hit the mode button twice until it is on RPM and that is how I use it. I set the RPM I need and turn on the motor. Now that VFD was set up by the maker of the spindle.

    Thanks Mike
    Last edited by gundog; 11-13-2011, 08:38 PM.

  • #2
    You can just size the vfd for the motor. In your case, 3hp. If in doubt, go bigger.

    You can run your motor faster if your bearings, lube, balance etc etc are ok. How fast? 50% faster (90hz) isn't unreasonable, BUT play it by ear...

    Brand? I like to Hitachi. try the WJ200 series. I've also installed a lot of Teco's, AB and a few others. Stay away from the cheap Chinese stuff - IMO.. not worth the "savings".
    Last edited by lakeside53; 11-13-2011, 09:19 PM.


    • #3
      Thanks Lakeside53,
      That is the info I needed.