Bonz, its a 3hp. The pressure switch was a very common rectangular Funas/Hubbell switch. I have another compressor with the same type switch and the instructions in the cover are the same.as the old switch that burned up and the new switch I just purchased.
I have another problem now that I need help with. Both the old pressure switch and the new pressure switch have a place for a small 1/4 line. The old switch didn't have a line running to it and it worked fine until it burned up. When I installed the new switch I decided to run the 1/4 inch line to it thinking it would allow the switch to function like it should. Well, when the compressor reaches the shut off point, it shuts down and then air bleeds from a small bleed hole in the fitting where the 1/4 inch line connects and continues to bleed until the cut-in point is reached. Any ideas on this one?? Cut-out is 140lbs cut-in is 115lbs. The switch came preset at this setting.