Is this normal operation?

[alex13177]

Rooftop package unit with TXV
Discharge pressure 285
Suction pressure 70
Sub cool 11
Superheat 30
Suction line temp 70*
Air across coil is 81* return and 61* supply

Also it was 96*F on the roof
Is the TXV stuck closed?

[git-r-dun]

No, it actually appears to be proper. TXV appears wide open but under a high heat load. A closed txv would give you a low suction pressure, high sub cooling, high superheat with a low delta T.

[alex13177]

No, it actually appears to be proper. TXV appears wide open but under a high heat load. A closed txv would give you a low suction pressure, high sub cooling, high superheat with a low delta T.

That's what I told the owner that the system is running at max capacity. She doesn't believe me, said it used to run cooler inside. It is almost 100*F outside and the store front is west facing with all window.
When I came to check the system, it was overcharge and cut off on high pressure. It was 106*F outside.

[Stohr]

They always say that when it is a 100 degrees out.

[Notasupertech]

Just a question,,,, what is the refrigerant you are working with on this system?

[dlove]

That's what I told the owner that the system is running at max capacity. She doesn't believe me, said it used to run cooler inside. It is almost 100*F outside and the store front is west facing with all window.
When I came to check the system, it was overcharge and cut off on high pressure. It was 106*F outside.

Is this a Carrier RTU? sound like one of mine...lol. but i have to agree this unit is balls out doing what it can.

[Chris_Worthington]

Looks pretty good but I question the Back pressure a little with an 81* return.....

If the condenser is a little dirty and a 285 head.... although that looks good and the Compression ratio looks pretty good, it could fool you if ya had a little dirt.... The compression ratio that is...

SC and SH look good.....

But would love to know the DSH, the 3rd piece in the puzzle

You could have a slightly week pump and sized on the edge.....

I would check it and pump it down "if" possible.

[Aalmaraz]

How do you know it was overcharged? Are we positive the condenser is clean? Did you recover and weigh it?

[rgb]

Just a thought how much O.A. is coming in

[alex13177]

Just a question,,,, what is the refrigerant you are working with on this system?

R22

[alex13177]

How do you know it was overcharged? Are we positive the condenser is clean? Did you recover and weigh it?

Yes, I cleaned the condenser after I saw the discharge pressure was like 350 and suction was above 100

[Bklyntek]

Possible dirt impacted in between the coils, check your condenser discharge air along the circumference of the coil. If you have sections where discharge air temp is greater that's where the dirt is and the coil is dirty. Next: change the the drier, yes carrier rtu's do sometimes allow too much out door air in to system.

[n-e-w Jerz!]

They always say that when it is a 100 degrees out.

yep... people aren't too bad during heating season but seem to loose their sanity during cooling season.