My Powermatic 66 tablesaw has a 3 phase 230 Vac motor on it but I cannot tell if it is a 3 hp or 5 hp. All the tags are gone from the motor. Is there any way to tell from the serial number? 8666-1008.

There will be a tag on the motor that will give the specs. Sometimes they are hard to see from the underside and its not easy to remove the top see them. Try lowering the motor (with blade removed) all the way and use a digital camera to reach up into the cabinet and photoqraph the top of the motor. I had to take several since your shooting blind to get a picture of mine.