I got the compressor for free, it was retired from the fire station, still in working order but 3 phase. I only dive here once a month around so I only needed 20-30 bottle fills for my 16 year old and myself, I can get free bottle fills mostly, so I am trying to keep cost down. My 16 year old really wanted this as a project so he has been looking at ways to get it rolling and this was an item that came up as possible solution for the least expensive one. I listed all my options and costs for VFD, Rotary Convertor and single phase. It is a MAKO air module with a three bottle bank that we would fill off of mostly. The compressor would run slower and I wasn't sure about what I would need to do for the compressor, It looks like there is a 5,5 model that would be similar to what mine will be after I loose 1/3 of the power out of the 7.5 hp motor. Was wanting to get any info on compressor I think its the Bauer KAP-14-7,5 H 1991 model. I can find the year the serial number and I know the motor HP and pressure it is set up for so that's what I think it is.