Single phase power draw to anticipate here guys?

I have a 10HP geared head, clutched spindle lathe for my home shop that I need to get powered up. The lathe runs on 600v input, 3 phase and 10.5 maximum amperage draw, from the tags. I have priced a 15kva auto transformer to boost 220 3 phase power to 600v, and am in the process of ordering a phase converter to feed it. The advice I am getting for a rotary phase seems to be overkill and gets me to wondering just how much single phase 220v power this lathe might draw? Experienced persons care to give me some insight on what I can expect in real world usage please?

Based on the tags, the wattage is (square root 3)*600*10.5=~11000 watts, so at 220V it would be ~50 amps at "Maximum Amperage Draw" at 100% efficiency in your conversion circuit. But that doesn't say anything about starting current draw, which can be huge.
A 100% efficient motor would draw 7460 watts, or 33.9 amps. So if that "maximum amperage draw" at 147% of theoretical seems a little low for including starting current.

Look here for a starting point(I haven't examined it it detail, but on a quick read through it seems right).

PowerTips: Motor Starting and Running Currents and Rating Guide

Lucky you with clutched spindle, in neutral you have only the motor draw to start amp load will be fairly low. My 7.5 direct drive lathe pulls the best part of 50 amps starting, lots of inertia with a 16" chuck and lots of big gears.

From the electrician view, not machinist view...
15KVA = 25A @ 600V 1Ph = 62.5A @ 240V 1Ph these are steady state values.
15KVA = 14.43A @ 600V 3Ph = 36.09A @ 240V 3Ph
Starting currents can be 6X higher, decreasing as the speed comes up. If you have the clutch your numbers should be dramatically lower than that.

For full 15KVA capacity you would need 62.5A x 1.25 (min motor circuit adder NEC) = 78.125A = 80A min 1Phase 240V circuit size.
This would be for the USA & the NEC, I suspect that your in the great up north with 600V equipment.
You should add a location to your profile for better service.

Hope that help you sort it out.

SAF Ω

Much simpler. You have a 10HP motor. It is capable of 10HP regardless of voltage or phases, meaning all circuit components must be sized for that possibility. So look up the circuit size data for a 10HP 230V single phase motor. 10HP 230V single phase is 50A in the NEC chart you must use for MINIMUM circuit sozing. Done.

Next step is to allow for losses in your system. Figure about 2% loss in the transformer, then assume 16% loss in the RPC, assuming it is sized 1kVA/HP as recommended. So at least 18% losses, 20% would be a safer assumption. 50A /.8 = 62.5 A circuit size from the single phase source, then another 20% de-rate (125%adder) for NEC conductor requirements makes it 78A. #4 stranded THHN 75C rated wire in conduit for most instances, if you want to use house wire (aka "Romex") rated 60C, you would have to go with #3 triplex.

Thank you so far guys, the input is welcome. The tags have it at 550 but requires 600 transformer to do that and the 15 KVA is also a good fit and a little larger than needed. The main issue here is trying to decide if I can get away with wiring this lathe to run on my existing service which is 60A out to the shop. So far it looks a little too close for comfort by the numbers so I guess I will order a 20HP rotary, (I have a 5hp here now that I can run in series if the 20 proves low) and I will try it on a 50A breaker. Come spring I will run a 100A service out there if any issues pop up, pun intended. I the meantime my electrician from work figures I won't have any trouble but I will continue to learn what I can. Just hard to think starting that motor all alone would be a problem, good thing I wont be running it overly hard.

Please do let us know if it starts and runs with the 50A circuit, as I'm sure that others will find that information useful in the future.

Another tidbit that could also be useful to others is the type (cu / alu), length and size wire of your 60A subpanel feeder. Feeder makeup can make or break a borderline condition.

Yep starting is the issue, running you will have more capacity than you will need.

SAF Ω

OK, final update. I ran the 100amp service out to the shop, figured do it sooner than later. I ordered a 20HP American Rotary converter with the optional capacitor kit installed and the transformer as mentioned before. The 100 A service is aluminum wire running 75' panel to panel. Now to the nitty gritty, I wired it from the single phase at 220 volts with a 60 Amp breaker(AR was talking 80-120)then it goes to a 3phase disconnect, into the transformer to be increased voltage from 220 3 phase to 600 3 phase. The 600 volt 3 phase goes to another 3 phase disconnect and then onward direct to the starter block on the lathe. The lathe starts crisply and there are no issues at this time. Wire gauge for all runs are normal, no extra heavy cabling involved for what it is worth.