Help selecting correct transformer for 440V Leland-Gifford drill press

I just acquired a 5 hp 3 phase Leland-Gifford No. 2 Multi-speed drill press. It was given to me by someone who bought it at an auction, not realizing how large and heavy it is (1510 lbs. and 8' tall). I picked it up yesterday. It is in my shop. It came from a school, and hasn't been under power in 30 years. It was completely painted over for sale purposes. When I got it home yesterday, I scraped the paint carefully off the motor tag. Yep.....440V only, 4 speed motor.

Best way to get this running inexpensively is to get a transformer. I've never had a large machine running on a transformer in my shop, so please bare with the questions. I currently have 2 American Rotary RPC's providing 3 phase power. A 10 hp RPC for everything 5 hp and less, and I have a 20 Hp RPC (CNC balanced)for operating my 10 hp Monarch lathe, 7.5 hp K&T 2K mill, and my Whitney 15 hp woodworking planer.

Here's what I would like to do, if it's correct. 3 phase, 250 V power coming out of 10 hp phase converter (American Rotary) to 3 phase shut off. My 3 legs are 250V, 250V, and 257V (wild). 3 phase shut-off output to correctly sized transformer. Transformer "out" supply to drill press. Please forgive poor terminology, and correct me where necessary. I want to learn.

1. Is 15 KVA the right size for this?
2. Would a 240V/480V transformer do the job for a 440V motor, or do I need something else?
3. Is it ok to feed the transformer 3 phase power coming out of the RPC?
4. Is there anything else that I need?


The electronics of this drill press are all located in the cast iron column, are precisely engineered and complicated, with wires going everywhere. I do not have a wiring schematic, so I don't want to mess with changing any of it. It would be a nightmare job for me. There is a control transformer in there, presumably to operate the starter. In my mind, it would be best to run the machine as designed, on 440V, and not change any of the complicated control wiring for all 4 speeds, and the gear head, etc......

Your help is appreciated.

I bought a new ACME three phase dry type general purpose about 15 years ago and they suggested 2:1, so I got a 3KVA for my 1 1/2 HP four speed

No issues ever on feeding with RPC and later Phase Perfect three phase makers

Works fine as a step up when actually a step down - says ACME. You just wire it up "backwards"

Its a 480 / 240 and the 1950 motor seems to care less about the fact that it getting 480 instead of 440

The transformer does very slightly HUM and also gets warm

Thanks, John. I'll be looking for a 15KVA transformer to be safe. They don't seem to be any more money than a 10KVA, from what I'm finding locally on the used market. At around $2K for a new one, I don't think I'll be going that route.