Aaon OAU compressor killer

[marylandtech]

Well I doubt it is overcharged, I just think it has too much load for the unit. All the motors are oem. I have washed them with a booster pump, plus you can see sunlight through the coil. The company who put the unit in is no longer in business either, wonder why? All four compressors are overamping due to the load. Also the high pressure cutout is 425 psi. I dropped Vfd speed to 40% but don't want to drop it too much. Do you guys know of any aftermarket parts to drop the head pressure?

Home depot sells nice garden sprinklers. As a last ditch temp solution it may work until the equipment sizing issues can be addressed. Just dont use it when its cool outside or you will have another set of issues. THIS IS A TEMPORARY BANDAID ONLY!

[maxster]

i would recover the freon till you get slight bubbles in the SG doing one circuit running at a time.... this unit is just discharging into the hallways with 100% OA why are you VFD controlling the motor it's constant volume isn't it...what is the temp rise thru the condenser coil with the ambient air.are the circuit condenser fans dedicated to each condenser coil put up a model i want to see this unit...scroll compressors

[gwoner]

Why isnt the HPS opening? Clean that condenser coil with compressed air then put a cottonwood screen over it

[duke of earl]

15 degrees subcooling on a package unit at design conditions is excessive. You should contact Scott Hamilton or Charlie DeWeese at Aaon for help. I have personally met these guys and they are pretty sharp techs.

[Six]

Home depot sells nice garden sprinklers. As a last ditch temp solution it may work until the equipment sizing issues can be addressed. Just dont use it when its cool outside or you will have another set of issues. THIS IS A TEMPORARY BANDAID ONLY!

We've used this before on a old ciller. It will scale up the coils.

[Burnedout]

Hey guys, the model is a RN-070-3-0-AA04-3D9. The hps opens at 450 psi not 420 as I mentioned before. I got a 24 delta t across the condenser coil. And as far as the Vfd, it came with the unit and is designed to operate at 57 hz, according to the sticker in the unit. It is constant volume, I had choked the Vfd down but don't want to drop it to much, cause them I will lose static and airflow.dont want to recover refrigerant because I will lose superheat and overheat comp. already at high superheat anyways

[duke of earl]

You need to call Aaon on this and not waste a bunch of time making changes. They need to know all conditions as they exist so they can review the situation. How old is this unit?