VFD can I use these!!

[drill]

can any one tell me how they work and if they will work for my application
Hurco kmb1 5hp. or would it be better to run a cnc rotary phase converter
single phase in and 3 phase out. what are my options and what would be more cost effective. The phase convert is around $400.00 is that more or less then a vfd and if a vfd is better which one and how do I size it to my mill.

[Al_The_Man]

If the only thing on your mill that is 3Ø is the spindle motor, then using a VFD will give you the feature of variable speed control, can also be CNC controlled by S command.
A good one for a 5HP motor is going to run around $1k.
Otherwise if you do not require the speed control feature then go with a rotary conv.
Some makes derate their VFD's when single phase in, some are made for 1Ø supply and no de-rating.
Al.

[drill]

Thank you.

[Rich Carlstedt]

I have a KMb3 with Ultimax II control

I split off the two transformers (control/servo)to single phase 220v,
and then fed a 3 phase convertor to drive the spindle.
I added a contactor which powers up the 5 HP VFD when Servo power is turned on,
and used the normal spindle motor contactor as the switch for VFD output.
If I wanted to, I could have robbed the reverse contactor for this, but left the setup almost Factory.
I have had no problems after 2 years of this.
No interference, nor any strange moves !
Rich