Anyone done this??
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Anyone done this??
We have run some CNC mills off of phase converters in the past with no problems. We used a good rotary style from Desco. http://www.deselectric.com/
Get a converter double your spindle HP and you'll be OK.
I got a 40 hp phase converter rotary(balanced) It seems to work ok I just have not done any cutting yet, Just Dry runs.
051101-1529 EST USA
ZR Machine:
HAAS Variable Frequency, Vector (really is variable freq), and DC Brushless (which are really ac synchronous) all are powered from a DC bus ( typically 325 v in the spindle driver). The The DC bus is from rectifiers from the AC mains. If the ac voltages are fairly well balanced under load and no load you should be OK. You do not want an unbalance that causes excessive DC bus voltage or excess ripple.
I haven't tried it, but a three phase AC synchronous motor (means it is also a real AC generator --- depends upon power flow direction) should probably build a better single phase to three phase converter, than the typical induction motor converters.
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In January I put in a VF-4 on a Phase perfect digital phase converter. The techs said they never saw power that balanced. The digital costs a little more but while you're doing setup it only draws a few amps, big rotarys draw alot all the time. It also has all sorts of protection built in. I have no complaints.
JP
One additional thing you can consider is adjusting Parameter 196 ACCEL LIMIT LOAD (I think that is the name). The factory setting is 195 and if you use programs where you overlap a rapid approach to the workpiece on all three axes with spindle acceleration at this percentage you will briefly draw much more than the nominal maximum current from the mains supply. Backing off the spindle acceleration to 120 does not seriously affect the time to maximum speed but it has a big effect on the peak current draw.
No problem, its actually amazing what you can get away with. The first converter I bought was big money and had terrible differences between legs. Machine runs great. All of the converters since then are a lot cheaper and are balanced near perfect at idle and load.
Gary