Strange TXV setup

[Chef]

Hmmm... two more plates and a HX were added, with presumably the same liquid line. An undersized liquid line would not be out of the question.

Now you will have to explain this one, 3/8" line - same compressor, suction controlled flow rate - what can possibly get outside of the parameters acceptable for this line by adding plates.

Speculations about many things are maybe OK but it does not get us any closer to understanding how the system worked as it was.

I am still convinced it was a critically charged orifice system not under txv control and have yet to see any compelling evidence otherwise. No blockages, no kinks, no hunting, line sizes OK and orientation of filter drier OK - though that is also a scratch the head item - what has it really got to do with the issue at hand?

Chef

[Gary]

Now you will have to explain this one, 3/8" line - same compressor, suction controlled flow rate - what can possibly get outside of the parameters acceptable for this line by adding plates.

Speculations about many things are maybe OK but it does not get us any closer to understanding how the system worked as it was.

I am still convinced it was a critically charged orifice system not under txv control and have yet to see any compelling evidence otherwise. No blockages, no kinks, no hunting, line sizes OK and orientation of filter drier OK - though that is also a scratch the head item - what has it really got to do with the issue at hand?

Chef

The TXV bulb charge is sensing freezer temp or it is sensing chiller temp. Either way it is not at its minimum flow position. It is running wide open with an orifice that is at least adequate if not oversized.

If there was solid liquid at the orifice the system would be flooded. Therefore, there is solid liquid at the sightglass but not at the orifice... ergo there is a restriction in between. Adding refrigerant drops the suction temp because it is overcoming the restriction.