Aaon OAU compressor killer
Hey guys need some help on an Aaon oau. Unit killed 3 comp. (locked up) last year and one so far this year. It is on an high rise apt. complex. The problem is when temps reach 95f the head pressure on all four circuits is about 400-410. suction is about 90-95, R-22. superheat is about 25 and subcooling is about 15. Pressures are higher when it gets above 100f. I have washed it, checked the motors, the fan blade depth, no recirculating air, etc.. Room setpoint on wattmaster is 74, it cools the hallways. It will sometimes reach it but comp. are getting crushed. I also have the same problem at another site with the same units. I looked at the blueprints and unit was designed for 90f outside air, which is a joke. Unit has supply vfd which runs at reference, have tried to slow it down which did work, but not good enough.Has anyone else had problems with these units?