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Originally Posted by reciprocal

We have Aaon MAU where I'm working now. Since it's an MAU there is no outside air damper. It's alwaysa pulling 100% outside air. I can understand your frustration with the dampers working in reverse. Let me guess normally...1st stage cooling is 100% outside air then 2ndi stage is compressor removing the heat from 100% return air. In reverse your killing efficiency.

The wiring does leave much to be desired. And why bother with a heat lockout relay when you can just, use a normally closed OAT.

Fixed

NOTE to self: don't use droid to post to forums anymore.
so when I type OAT OR MUA they stay as I meant them too.

We have Aaon MAU where I'm working now. Since it's an MAU there is no outside air damper. It's alwaysa pulling 100% outside air. I can understand your frustration with the dampers working in reverse. Let me guess normally...1st stage cooling is 100% outside air then 2ndi stage is compressor removing the heat from 100% return air. In reverse your killing efficiency.

The wiring does leave much to be desired. And why bother with a heat lockout relay when you can just, use a normally closed AOT.

Originally Posted by Six

I hate Aaons.

I had a hotel that had a mold issue so they called Aaon and we did the duct work.

An Aaon rep installed a custom built 30 to split 100% out side air unit.

Hot gas reheat.

It NEVER worked correctly. Aaons engineers and the rep came out and worked on it and finally after 3 weeks gave up.

Every Aaon Ive come in contact was a POS.

Give me a Munters any day over a Aaon.

I agree, I hate Aaon as well. I have installed 8 of them and every single one has come from the factory with problems. 2 of them came with no charge, found a place where the copper was rubbing the unit during shipping. 1 came with a digital compressor controller that was wired wrong, 2 came with bad contactors and the other 3 came with the outside air dampers operating backwards. The one that had the bad digital compressor controller had a problem where the fan would not shut down when the high static safety tripped and I wound up finding that they wired 24vac straight from the transformer to the relay that was supposed to shut it down

Their wiring diagrams are nice but they do not label their wires at all. I was trying to find the wire that carried 24vac to the outside air humidity sensor and I bet they had 100 red wires with no labels tied in to the low voltage terminal block, I had to pull them off one by one and ohm them out to find it....

I hate Aaons.

I had a hotel that had a mold issue so they called Aaon and we did the duct work.

An Aaon rep installed a custom built 30 to split 100% out side air unit.

Hot gas reheat.

It NEVER worked correctly. Aaons engineers and the rep came out and worked on it and finally after 3 weeks gave up.

Every Aaon Ive come in contact was a POS.

Give me a Munters any day over a Aaon.

I have some large Aaons on some accounts, and you have to watch the blower wheels on these. The rivets will fall out one by one, which will walk your fan off its mounts if you fail to catch it. True story. We have changed several, all with rivets missing.
Other than that, TXV's and a fan drive.
I still like the design and dependability overall.

Other manufacturers do it all of the time as well. If you or I do it we are " hacks " .

I like Aaon for thier electrical diagrams and wiring. Thier refrigerant piping , not so much. You know I went to thier factory class for a week and had a blast.If I ever find myself single , I'm thinking Tulsa ( yes I know this doesn't help you now ).

Take the " Tulsa attitude " ...if it isn't leaking why worry.

AAON and Quality...

Been awhile but a new customer has a roof full of em and the Gymanasium 30.5 ton has left me wondering.

Here we have a 7.5 ton txv 5/8 inlet, being fed with a 1/2" line, no bushing, just the 1/2" pushed into the 5/8 at an angle and filled (mostly) with braze, this one had a pinhole on the braze and lost it's charge.... 3yr old unit. The other 3 tx's are identical.



Repaired, replaced filter drier, pressure tested w/nitrogen and vacumed down to 500 mic's. Weighed in 296 oz (18.5lbs) R-410A per tag and started, do not recall high head, returned 4 days later to check and found off on high head. Re-checked pressures and found @ 78 deg outside, 74 inside, 420/125 psi, 22 degrees sub, 12 deg superheat at comp. The circuits that remained operating I had previously topped off after cleaning both plugged condensers that had been plugged for ??? and found low after, to 350 head. Those are operating at 10-12 degree subcooling. Pulled 3 lbs out of the first circuit, and checked the 4th and found it high as well (this circuit was also off on high head with the plugged coil) pulled 3 lbs out of that one as well and now have all 4 operating around 350/120 with 10-12 sub and 12 super at the comps........WTF?? Running bout 16-17 amps on all legs 25 FLA.

My scale is less than 1 yr old, and the 4th circuit was over as well.

I've braze adapted in a pinch, but this is factory.

Well......... job security!

I will say this, it was very easy to access and repair. On second thought, wtf am I complaining about?