[HomerSimpson]

Just bought a used omax maxiem waterjet machine with a 40HP, 3ph, 480V pump and am starting my research to get from 240V to 480V and single to three phase. It came with a 75KVA transformer to go from 240 to 208, which I am questioning because I am pretty sure the motor is 480V.

Seems to be lots of phase converter suppliers:
1. https://www.phase-a-matic.com/
2. https://kayind.com/
3. https://www.americanrotary.com/
4. TEMCo 3 Phase Converter, Rotary Three phase converter sales since 1968
5. https://phoenixphaseconverters.com/
6. https://www.3phasepower.ca/
7. https://www.northamericaphaseconverters.com

and options:
1. rotary
2. VFD
3. other?

Before I got too far, I thought I'd survey the live studio audience to see what you have done and if you have any regrets.

[Jim Dawson]

Let's start with the question of how much 240V single phase power do you have available? A 40HP motor is going to need about 200 amps of 240V single phase. You also need to confirm that the pump motor is wired for 480V. The fact that it came with a 208/240 transformer would cause me to check the motor wiring first. But assuming that the motor is 480V only, then you would need a 240/480 transformer after the phase converter.

Then a Phase Perfect or RPC of the proper size would be my choice for that application. I think any of the vendors you listed would be fine.

[HomerSimpson]

I have a 600 amp service. I stepped through Phase Perfect's wizard for selecting a converter but they don't sell one large enough.

What are the advantages/disadvantages of stepping up the voltage before or after the phase conversion?

[machinehop5]

.think backwards...
just be4 it happanned https://en.wikipedia.org/wiki/Timeli...rating_systems

Mickey Mouse

[Jim Dawson]

I have a 600 amp service. I stepped through Phase Perfect's wizard for selecting a converter but they don't sell one large enough.

What are the advantages/disadvantages of stepping up the voltage before or after the phase conversion?

That's a lot of single phase 240 service. Any chance you could get 3 phase power installed?

I think a rotary phase converter is the way to go, but I have never seen a 480V rotary phase converter. Having said that, I guess one could be built. The capacitors and switchgear would have to be rated for 480V use. Any 3 phase motor of the size (about 50 - 60HP) you would need would be rated for 480V so no problem there. I don't know of any disadvantages related to stepping up the voltage prior to converting to 3 phase, other than maybe the cost of the higher voltage components of the rotary phase converter.

Given that the transformer that came with the machine is a 208/240, 3 phase, the machine may be wired for 240V already. I would confirm this before I got too deep into a step up transformer.