What kind of oil is best for use with an open (shaft driven) compressor to be used in northen climates. It is expected to run between 300 and 800 rpm's for refrigerator room and reach in freezer.
Thanks Drkillroy
Most large compressor manufacturers are running a polyglycol based oil in R-290 service. A couple of manufacturers are CPI in Michigan and Mobile out of Germany. You will need to watch the oil viscosity to be sure it is the proper visosity for the compressor. The polyglycol based oils are thick in the undilutes state, but once in the compressors, the viscosity will come down to the normal range due to the dilution with the refrigerant.
What kind of compressor are you running. Might be best to contact the manufacturer and se what oils he has approved fro H-C service.