I acquired a 10 hp Ingersoll Rand T30 Compressor for my shop. It is 3 phase. I have phase converters already but I want to just run it on 220 single phase. My current compressor is a 1960's vintage 60 gallon I think . I am running it with a 220 single phase motor that I am going to put on the Ingersoll Rand and try. This motor has no tag and I bought it at an auction. We are thinking 10 HP but certainly bigger than 5 HP. I have run it for 15 years through the 2 pole pressure switch with no motor starter. Works fine. However, I wonder if the motor wont pull too many amps running the big compressor for the pressure switch to survive. The Ingersoll Rand is set up with the same model 2 pole pressure switch but it was used as a control circuit only and the compressor I assume had a motor starter that I did not get. If I set it up with a motor starter, how will it be wired through the pressure switch and what will one cost? The compressor was pretty well free but I am kinda on economy shop parts mode right now. I plan to use the pulley off the 3 phase on the single phase and try it at the same RPM. If it wont run the compressor that way (probably means its a 7.5 rather than a 10hp) I will try a smaller pulley. My air demands are not that great and I can certainly wait for it to build up with a smaller pulley. Again the motor has run the smaller compressor fine through the pressure switch but if it arcs and sticks the switch contacts it would run till it is switched off. I don't leave the compressor on unless I am working in the shop but i might walk to the house for a while and leave it on. How do you hook up a motor starter?