OT: Phase Conversion, For running a compressor Options

[McMark]

I have a 7.5 HP vane type compressor that I am researching how to run on single phase power. Swapping to a single phase motor is not an option. Anyone have any knowledge of sizing a phase converter? It looks like I can find rotary phase converters that say 7.5 HP for around $600. But I don't know if this is one of those situations where I really should be getting a 10 HP converter for the 'extra overhead power'. Advice?

[burton73]

I had a factory that had no 3 phase power at one point and a had a lot of equipment that was 3 phase and one big wet sanding mill that had a 7.5 HP head. I used a bunch of small low cost $125.00 phase converters boxes but found then not to work right with the big motor. They where fine for the buffers thought. The motors did not give you the true power with them and you had to spin then by hand some times.. I bought a set up that was a 10 HP motor on a base that turned all the time and it made 3-phase power by changing the phase to a box /panel that was part of it . I was able to run the full shop, all 3 phases on this panel just like it was
3 –phase coming in by the city. In the morning I would just turn it on. It did not make any noise, as it was just the motor turning. This was 17 years ago. They may have come up with something different in this time. I paid $600 for the 10hp used. And it will suck amps if you are doing this at home. It was 220V.

Bob Burton