Compressor flooding

[coolerik]

Either u gotto some f ed up stuff goin on or yer insternents are out.... its friday and im well into a case so im having a hard time deciphering the numbers.. oh and go Canucks,!! Sorry ****cago blackcocks

[jpsmith1cm]

You want to stick with dew point data for the suction line.

Look at how a blend works. At a given pressure, you start evaporating at the bubble point. This is the lower of the two readings given. In our case, that is 32F. As the refrigerant continues to boil at a constant pressure, the temperature actually rises to the dew point readings.

This is why it is THEORETICALLY possible that your readings are accurate but, if they are, your compressor is in a WHOLE lot of trouble.

I would start looking closely at the evaporator and what is going on there that is causing you to either not absorb heat or to overfeed refrigerant.

[icemeister]

As was mentioned early on in this discussion, it's possible the compressor isn't pumping as it should. If the valves are bad and it's only pumping at 50% capacity, your TXV will be way oversized and tend to cause such a flooding condition.

At this point, I usually check the compressor amp draw against the manufacturer's published performance data. Get the compressor model number, the actual supply voltage, the suction & discharge pressure and we can look it up. It's amp draw should be withing 10% of what the data says it should be or you have a bad pump.

[Tommy knocker]

Actual with a thermometer, and I know the numbers are confusing that's why I'm asking for help.

Ok. I'm going to suggest you verify your gauges and thermometer are calibrated and correct. If they are then your problem is over my head. Would have to be there and put my hands on it.

[Dchappa21]

I would recommend recovering your gas and starting with virgin refrigerant.

Could be your gauges too.. Have you tried another set?

Normally with that high of suction pressure your high side will be through the roof.

So, it's either a bad compressor, bad gauges, or mixed gas.

I would also check you equalizer line on your valve.

[Dchappa21]

Whoops missed where you said no equalizer line... How old is the coil? No distributor right???

[eddiegoodfellar]

Any large leaks on the system in the past? Maybe it's time for some virgin refrigerant.


I would recover some refrigerant and check the saturation to make sure the refrigerat itself is good.
This and the compressor efficiency test could save you a bunch of time in the long run.

I pretty new to refrigeration but that is where I would start.

Please post your findings when they are determined.

[thethomas4]

Yea, thru the TXV equalizer but the SH would be way low measured at the compressor and way high measured at the evap but wouldn't one visually see this while troubleshooting?

Here is a picture of what that looks like on RIFF case. Coil and distributor was clear case at 35*

[icexprt]

So, you're now claiming a subcooled suction line?

32F SCT (this is wrong, but I'll play along) with a 25 degree suction line?

5 degrees suction subcooling?



Your readings are wrong, friend.



icexprt,

I've seen suction/liquid heat exchangers blow out and leak through. Not very common to see that particular part on smaller equipment like this.

Maybe I'm using the wrong term to describe the part I'm referring to.... Refrigeration Research calls it a "subcooling heat exchanger". I've attached a picture... I hope it works...first time posting a picture! I've seen them on even smaller walk-ins before.

[jpsmith1cm]

Maybe I'm using the wrong term to describe the part I'm referring to.... Refrigeration Research calls it a "subcooling heat exchanger". I've attached a picture... I hope it works...first time posting a picture! I've seen them on even smaller walk-ins before.

Yeah, I knew what you were talking about.

I've seen a few of them rupture before. Finding the first one is the worst.

They don't do a lot of subcooling, really.

[fr420]

Maybe I'm using the wrong term to describe the part I'm referring to.... Refrigeration Research calls it a "subcooling heat exchanger". I've attached a picture... I hope it works...first time posting a picture! I've seen them on even smaller walk-ins before.

Thanks for all your help guys and sorry I got a little pissy at times. The promblem was the the subcool heat exchanger!!!!

[jpsmith1cm]

Thanks for all your help guys and sorry I got a little pissy at times. The promblem was the the subcool heat exchanger!!!!

Good find.

My first one took me 3 service calls over 2 days to find and correct.

[fr420]

You want to stick with dew point data for the suction line.

Look at how a blend works. At a given pressure, you start evaporating at the bubble point. This is the lower of the two readings given. In our case, that is 32F. As the refrigerant continues to boil at a constant pressure, the temperature actually rises to the dew point readings.

This is why it is THEORETICALLY possible that your readings are accurate but, if they are, your compressor is in a WHOLE lot of trouble.

I would start looking closely at the evaporator and what is going on there that is causing you to either not absorb heat or to overfeed refrigerant.

I understand exactly what your saying, but the condition I was having The dew point reading would give me a subcooled suction line, and the bubble point reading was only one that made sense because as we know now I was coming back straight liquid.