[How do I?] Convert my Shop's 240V 200 amp Single Phase to 30 FLA 3 Phase for my Tree 310 mill?

Utah Smitty

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Nov 15, 2013
I just bought a Tree 310 CNC Vertical Mill. It has Dynapath CNC control. In fact I barely get it off the trailer earlier today. It comes with factory setup 230V 3 Phase 30 FLA power requirements--what is the least expensive means to convert my single phase 240 volt shop power to operate the machine?

Rotay Phase Converter (How Big?) Static Phase Converter; VFD on spindle drive and 110V single phase on controller.

Any specific manufacturer/model recommendations?




Active Member
Aug 3, 2017
30A means about 10 HP? VFD is very easily the best.

I just got this VFD for my lathe https://www.ebay.com/itm/CE-UPDATED-7-5KW-220V-10HP-34A-VFD-VARIABLE-FREQUENCY-DRIVE-INVERTER-GOOD/112087636900?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

One of the chinese ones, but very much the best documented and best constructed. There are some 10 HP VFDs on ebay for about 100 less but I presume they are like the rest of my VFDs, which are a little tougher to read the documentation and somewhat less substantial: https://www.ebay.com/p/1-5kw-2hp-220v-Variable-Frequency-Drive-Inverter-CNC-VFD-VSD-Single-to-3-Phase/8031751964?iid=283047413319&rt=nc


Active User
H-M Supporter - Gold Member ($25)
Jun 12, 2014
I believe it requires a 30A service 240VAC, the main mill motor is 2 Hp, the axis drives are DC servo. Since it is CNC, has multiple drives and electronics, I would go with an RPC, probably 7.5 Hp but depends on the make and recommendations. Be sure to check the circuity so that the wild/generated leg is only used for the main mill drive motor and not the drive circuity. Others have more experience as to RPC recommendations. I saw one of the American Rotary AMP RPC's at the BarZ, very compact and quiet, pretty much plug and play. It comes in 5, 10 and 20 Hp portable cubes, probably recommend the 10Hp. Also look at their AD series, although there are a number of manufactures. Otherwise many people buy the control panel and build their own.
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H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Oct 14, 2014
My son has a dynapath on a similar mill. Got it running for him.

Everything except the spindle and coolant pump is single phase. Replaced the spindle contactors with a VFD. Put in a single phase coolant pump.


H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Nov 13, 2012
My son just purchased the American Rotary AMP rotary phase converter, 10HP I believe. He had them add two additional 3 phase plugs/outlets and a breaker to the front panel. He's happy with it so far. I have a small rotary phase converter for my Bridgeport mill (3 HP PhaseMatic), and I will say that the ability to move the American Rotary box around to where you need it is very convenient, particularly if you only have one 220 outlet in that area of the shop, and several different machines that you want to use it with.