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| Generally, I try to stay out of the "Phase converter" threads, because I'm really not sure what's being talked about.
Now, let me explain that.
The RONK and a couple other phase converters are actually a motor/generator set would on one shaft. A single phase motor drives a 3Ø generator, much in the manner of Ed's and my Lincoln coffee grinders. The output of those machines is genuine 3Ø power.
The 3Ø devices so commonly referred to on so many machining boards, using an idler motor to "generate" the third phase are NOT converters, and they do NOT make 3Ø power. They simulate a 3rd phase that really isn't 120° from the A and B phases coming in, and the voltage can be 40 volts high or low, based on the testing I've done. At best, they are a "good enough" solution when it comes to running a motor load for a LIMITED time period. I have one I built in a buddy's shop that has worked good enough for the last 4 years. His machines don't run 8 hours a day.
I've had more meters than I can count on that device, and a scope, and frankly there are times when I wonder how machines run from it. They do though.
There are a load of problems that can be encountered when running a phase faker device, from motor horsepower derating to overheating. The major problems seem to display themselves in control equipment, be it 115 volt or even 24 volt. Unless the control circuit is wired across A nad B phases, you will see problems. Usually, this isn't difficult to accomplish. A control transformer wired from A or BØ to the derived artificial phase becomes a nightmare, and generally smokes.
Welders especially 3Ø welders are an equine of a different hue. The motor/generator sets, like the Lincoln coffee grinder will operate on the phase faker, and will also loose a little of the top end of the machine's amperage. A 3Ø transformer machine will L I M P along, and might appear to be making DC to the average person. Since it isn't getting 3Ø, only 2 of the 3 transformers in the machine are powered, and the 3Ø rectifier isn't outputting anywhere near its capability. The transformers also overheat rather quickly.
So, the long and short of the whole thing is, motors run well, transformers don't.
For my money, were I in the shoes of Farmer X in the middle of REA noplace, and had need for 3Ø power a few weeks a year, I would buy a Diesel Generator. Depending on your KWH rate and line construction costs, the payback might be rather short, and you'd have backup power at no additional cost.
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Wire feed welders again
