As was said before, this application of phase converter is uncommon because the HVAC is normally a design item-it wouldn't be designed to be 3 Ø in a 1 Ø area. The only ones I have sold are used for a specific piece of equipment that was obtained(mill, stamper, autoclave, etc.) and the shop was only 1 Ø. You can get a price pretty fast, and I think that, along with conversion power loss, may change his mind. Good luck.
