I don't recall the specifications on the RPC, but we ran syncrowave 500's on them at the metal working apprenticeship I did. I think he ran an inverter no problem as well. Highest AMPS I ran was 430 on a pulse setting
As far as I remember Miller Syncrowave 500 were single phase input not 3-phase. And on the 180 Lincoln motor/generator the RPC powered the welding generators electric motor that in turn drive the generator. In regard to powering a 3-phase transformer or inverter power source with an RPC you're going to be disappointed. That said I have seen it done. I already know some people may disagree, but for one reason if you have the power sources control circuit feeding off the generated 3rd leg you're going to have all kinds of problems. If the power source has 3 phase DC rectification the arc will most likely be very erratic. You could even have arc pop outs, there's other reasons such as it would never be used in some code work applications. Thats the 2 cents worth.
After a search you seem to be right, no mention of them being 3-phase. Not sure why he would have said they were running 3-phase. If they were then the arc was just fine, but if they were single then I have no first hand experience
Yes, Page 27, left hand side- the input only uses two legs.
Most people assume 460 as 'three', but there's no 'rule' that says one needs to use all three legs.
In TIG machines, it's very common that they're only single-phase, as they run the secondary (welding) current out as AC for aluminum and other metals, where AC causes a 'cleaning' action.
Newer inverter-based machines 'synthesize' AC by switching in both directions, and frequently, they're programmable to be assymetric (more in one direction than the other) to enhance cleaning-action. There's a few non-inverter types that use some fascinating magnetic prowess to yield an assymetric AC waveform for the same purpose... and I'll discuss it with anyone interested, but it's somewhat off the topic of this thread.
Seems like a non issue for the op now but regarding the original question - yes. I have a big miller cp 302 cv power supply running on an rpc. Works well so far. I tried first to do the single phase conversation but didn’t like the result. Voltage would drop 10v when I started welding with the single phase conv. So changed it back and now using it on my rpc.