Best option to power 3 phase 20hp 460v lathe motor from 220v single phase input?

[Leowren]

What is my best option to power a 20hp motor in a Monarch lathe? Currently wired 460v with full load amps at 32. My incoming power is 220v single phase 200 amp service. I’m thinking a rotary converter and transformer together will be my best option? I spoke with someone at phase perfect about their combo converter transformer and they said I’m just above the cut off for full load amps on the largest 20hp model.

 

[Karl_T]

Make SURE that motor can not be rewired for 220, most can. If not it may be best to get a 220 version. If you are any where near me I just scrapped a Mazak M4 with 20 hp motor.

Otherwise get a BIG step up 3 phase transformer. Use an RPC to make your 220 3 phase. 440*32*1.7= 25 KVA transformer

We did this on our 440 only waterjet. Works just fine.

 

[mksj]

Might be more cost effective to replace the motor, or at least get one with a higher efficiency at 460VAC (newer motors are 23-25A). Phase Perfect has 20Hp voltage doubler converters rated to 32A @460VAC, but quite expensive. Alternative less expensive would be a 230/460VAC motor and direct wiring to at 230VAC output using a 40Hp VFD running in derated mode for single phase input. Fuji drives are often used with single phase input and have posted derating output amps. I did a similar VFD conversion/build for a 10 Hp Monarch 61 lathe.

FRN040G1S-2U Fuji VFD Drive: 40 HP 230V 1 Ph or 3 Ph Input 3 Ph Output | Slaymaker Group

FRN040G1S-2U Fuji VFD Drive: 40 HP 230V 1 Ph or 3 Ph Input 3 Ph Output Variable Frequency Drive 40 HP 200-230V

slaymakergroup.com

 

[Leowren]

32 full load amps is the combination of 4 motors- main drive motor, hydraulic pump motor, rapid traverse and coolant pump.

 

[rons]

I’m thinking a rotary converter and transformer together will be my best option?

What is the lathe main motor Hp?
What RPC motor size do you think you need?

 

[Leowren]

The main motor is 20hp so I think the converter needs to be 40hp? I thought the phase perfect voltage doubling converter looked like a good option but I guess I’m just over the capacity.

 

[john.k]

With a bit of common sense and care ,you will never use the full 20hp of the lathe ,so a bit of under spec on the VFD probably wont hurt.

 

[metalmagpie]

Next you're going to tell us your budget is $200.