Hey guys, I've got a good one. Walkin freezer, 404a, Copeland Diskus compressor. Pressures good, and oil pressure switch recently changed. Temps good, sight glass 90% full at start to 30% by completion of cycle, about 12 minutes. Every 5 to 6 weeks oil pressure switch trips. Oil pressure 45lbs. constant above suction pressure. No crank case heater, unit pumps down.Unit has been in operation for 6years.