220v Compressor noise Grunert holding plate system

[Sailing Drummer]

After the boat show">Annapolis boat show last October I bought a Cool Blue system. It took until about a month ago until I could get a refrigeration mechanic to come down to the boat to vacuum out the refrigerant in the old system so I could take it apart (miserable winter here last year). I've got the Cool Blue installed except for the electrical, which I'm hoping to finish tomorrow if I can get to the boat.

[Richard Kollmann]

David, I have read through your performance data information and temperatures at this point is of no value to me now. Whether this is a Crosby/Adler Barbour or Grunert unit it is the right quality of and capicity for a 55 ft boat’s twin boxes. The ½ HP compressor is capable of freezing 300 pounds of frozen +10 degree F eutectic solution in two hours. Comparing your system to a Danfoss 12/24 volt BD compressor’s capacity of 4 to 6 pounds of ice after two hours running time is a poor suggestion.

The first item that jumps out as a performance or design problem is frost seen in the liquid high pressure side of system. The Sight-glass and the solenoids are never colder than your seawater cooling mediums temperature. First problem to solve is finding restriction where frost starts in high pressure side of system, this restriction will be in a line or filter anywhere from refrigerant coming out of condenser to sight glass I would guess. On the side of receiver storage tank there is usually a three way valve (King Valve) this valve when opened all the way counterclockwise allows full flow of refrigerant and closes the small servicing port under the leak proof 1//4 inch flare cap. If King Valve or line shortly after leaving valve is colder than receiver it may not be full open. Be careful not to close this valve as explosive high pressure can be produced by compressor.

After the frosting of high pressure side of system is corrected there are no two of these systems the same. First the noise could be caused by:

Worn compressor rubber shock mounts bottoming out. To confirm this as cause of noise push a tapered piece of wood under compressor taking some load off mounts. Then either adjust mount or live with the noise

Compressor inside metal can rides on four springs and noise could be do to a dislodged or weak spring and will operate OK for years that way.

The only serious problem is if noise is refrigerant vapor still contains liquid when returned to compressor. First sign of saturated liquid interring compressor is a pinging or tinning sound, if not corrected it can cause compressor reed valve failures. Tampering with refrigerant volume or expansion valve orifice control will allow evaporator coil inside holding plates superheat to change and flood return line to compressor. The design objective is to confine the phase change from liquid refrigerant to vapor while inside holding plate’s coil and not in line returning to compressor.
I have never seen two ice box conversion units perform the same or is refrigerant flow always perfect. The best you can hope for is keeping high and low refrigerant pressures at an efficient pressure range and refrigerant phase change inside refrigerated boxes.

Some of the better holding plate systems have a suction line accumulator to trap liquid refrigerant and oil long enough to meter it slowly back to compressor. Holding plates create a problem on each cycle start up of compressor in that during off cycle refrigerant and some oil will migrate to the coldest part of system, the holding plates. On the next compressor start if plates are already cold and evaporator coil is full of liquid it will move quickly into return line possibly flooding compressor.

RECOMMENDATION

Run three separate tests one each Day with system turned off each night, Refrigerator only, Freezer only, And third test both system at the same time. Provide seawater and air approx temperature that day.
To obtain information to Fine tune your system Do a 90 minute test run each time recording every 10 minutes the following ; High Pressure, Low pressure, Any place you see frost . Also report approximant temperature of lines to and from condenser and return line at compressor. Also make note in the 90 minute test when thermostat stops compressor. Line temperature reported in Hot, Warm, Body temp, and cold. Actual temperatures of plates not needed till follow up fine tuning is done later.

Please send Picture of one of the Expansion valves.

[botanybay]

Originally Posted by Richard Kollmann

David, I have read through your performance data information and temperatures at this point is of no value to me now. Whether this is a Crosby/Adler Barbour or Grunert unit it is the right quality of and capicity for a 55 ft boat’s twin boxes. The ½ HP compressor is capable of freezing 300 pounds of frozen +10 degree F eutectic solution in two hours. Comparing your system to a Danfoss 12/24 volt BD compressor’s capacity of 4 to 6 pounds of ice after two hours running time is a poor suggestion.

>> Thanks!

The first item that jumps out as a performance or design problem is frost seen in the liquid high pressure side of system. The Sight-glass and the solenoids are never colder than your seawater cooling mediums temperature. First problem to solve is finding restriction where frost starts in high pressure side of system, this restriction will be in a line or filter anywhere from refrigerant coming out of condenser to sight glass I would guess. On the side of receiver storage tank there is usually a three way valve (King Valve) this valve when opened all the way counterclockwise allows full flow of refrigerant and closes the small servicing port under the leak proof 1//4 inch flare cap. If King Valve or line shortly after leaving valve is colder than receiver it may not be full open. Be careful not to close this valve as explosive high pressure can be produced by compressor.

>> I may not have been clear, there is no frost on the high pressure side. There is frost on the check valve in the return side (low pressure) just before the two circuits come back together.

>> There is no second circuit at this point. The refrigeration plate developed an internal leak of refrigerant into the eutectic solution and a leak which allowed the eutectic solution to slowly leak out of the plate. The plate was empty of solution when I discovered this. There are two solonoid valves one for each circuit. The one for the fridge side is disconnected, the bad refrigeration plate removed, the high pressure side line to the fridge plate was capped, the low pressure side line from the plate was capped. So essentially this is for the time being a single circuit freezer only system.

After the frosting of high pressure side of system is corrected there are no two of these systems the same. First the noise could be caused by:

Worn compressor rubber shock mounts bottoming out. To confirm this as cause of noise push a tapered piece of wood under compressor taking some load off mounts. Then either adjust mount or live with the noise

Compressor inside metal can rides on four springs and noise could be do to a dislodged or weak spring and will operate OK for years that way.

The only serious problem is if noise is refrigerant vapor still contains liquid when returned to compressor. First sign of saturated liquid interring compressor is a pinging or tinning sound, if not corrected it can cause compressor reed valve failures. Tampering with refrigerant volume or expansion valve orifice control will allow evaporator coil inside holding plates superheat to change and flood return line to compressor. The design objective is to confine the phase change from liquid refrigerant to vapor while inside holding plate’s coil and not in line returning to compressor.

>> I don't see any indication of liquid returning to the compressor. The low pressure return rises up into the condensor (both high side and low side run through the condenser along with sea water). There is never any frost or low temp coming off of the jump from the condensor (low pressure side) to the compressor inlet. I suspect a bad spring is probably the most likely.


I have never seen two ice box conversion units perform the same or is refrigerant flow always perfect. The best you can hope for is keeping high and low refrigerant pressures at an efficient pressure range and refrigerant phase change inside refrigerated boxes.

Some of the better holding plate systems have a suction line accumulator to trap liquid refrigerant and oil long enough to meter it slowly back to compressor. Holding plates create a problem on each cycle start up of compressor in that during off cycle refrigerant and some oil will migrate to the coldest part of system, the holding plates. On the next compressor start if plates are already cold and evaporator coil is full of liquid it will move quickly into return line possibly flooding compressor.

RECOMMENDATION

Run three separate tests one each Day with system turned off each night, Refrigerator only, Freezer only, And third test both system at the same time. Provide seawater and air approx temperature that day.
To obtain information to Fine tune your system Do a 90 minute test run each time recording every 10 minutes the following ; High Pressure, Low pressure, Any place you see frost . Also report approximant temperature of lines to and from condenser and return line at compressor. Also make note in the 90 minute test when thermostat stops compressor. Line temperature reported in Hot, Warm, Body temp, and cold. Actual temperatures of plates not needed till follow up fine tuning is done later.

Please send Picture of one of the Expansion valves.

>> Thanks! At this point the above data is for a single circuit freezer only. The two plates are in series, both are freezer plates. I will take the data above and convert it into the data you are looking for this evening.

I really appreciate the help trying to determine what is a good path forward for this system.

[Richard Kollmann]

I understand there are two series plates in freezer and one expansion valve for each box. I worked with a freezer with seven plates 20 years ago and two years ago they were all performing well. The object now is to balance each box's refrigerant flow based on flow performance and not super heat as superheat will be a by product of flow bias during a 90 minute run of each box. The pressures you reported were from a system with a liquid flow restriction as indicated by frost in the wrong places. Remember holding plates low pressure is in transit to a point 20 degrees below eutectic’s completely frozen point unlike a standard much more stable evaporator plate. Normally on systems like yours the refrigerator TXV is set to a differant superheat than freezer so both boxes can freeze plates during the same compressor run cycle.

[botanybay]

Thanks again! Pulling together the information.

Definitely no frost anywhere on the high pressure side.

Fridge plate has failed (developed a refrigerant leak into eutectic solution & bulged plate, then pushed fluid out of the plate)

So at this point this is a single circuit freezer only system. Fridge circuit is completely capped off

Next message will have temp and pressure data.

Circuit for system looks like this:

Compressor High Pressure Port
|
Salt water heat exchanger
|
Receiver
|
site glass
|
|--- High pressure test port
|
Freezer Solenoid (just after a 'T' for the capped off fridge Solenoid)
|
15 feet of 3/16 (I think) copper tubing
|
Expansion Valve on Freezer plate 1
|
Inlet port of Freezer Plate 1
|
Outlet port of Freezer Plate 1
|
Inlet port of Freezer Plate 2
|
Outlet port of Freezer Plate 2
|
Expansion valve sense bulb
|
15 feet of 3/8" (I think) copper tubing
|
Low Pressure side check valve (Just before 'T' for capped off Fridge check valve)
|
salt water heat exchanger
(appears to be using cold return to cool hot compressor output)
|
Compressor Low Pressure inlet
|--- Low pressure test port on stub on compressor body labeled suction

[botanybay]

> Run three separate tests one each Day with system turned off each night,
> Refrigerator only, Freezer only, And third test both system at the same time.

For the three runs, only one is possible. As the refrigerator circuit plate failed, plate removed and both high pressure and suction side are capped.

> Provide seawater and air approx temperature that day.

Water temperature 69F
Air Temperature 71F

> To obtain information to Fine tune your system Do a 90 minute test run
> each time recording every 10 minutes the following ; High Pressure, Low
> pressure, Any place you see frost . Also report approximant temperature of
> lines to and from condenser and return line at compressor.

Note that return line to the compressor is prior to the heat exchanger which has salt water, high side, and suction side all together. Jumper from heat exchanger to compressor is very short. Measuring suction pipe just before compressor pallet.

Note that the low pressure is measured from the suction stub on the compressor body labeled "Suction"

Time 0 min (before start)
High Pressure: 75 psi
Low Pressure: 72 psi
Frost: None anywhere (system is off)
Compressor to Condenser Temp: 72F
Condenser to Receiver line: 72F
Return line at exit of plate 2 TxBulb: 72F
Return Line at Compressor: 72F

Time 12 min
High Pressure: 92 psi
Low Pressure: 9 psi
Frost: On expansion valve
Compressor to Condenser Temp: 121F
Condenser to Receiver Temp: 80F
Return line at exit of plate 2 TxBulb: 68F
Return Line at Compressor: 72F

Time 23 min
High Pressure: 87 psi
Low Pressure: 8.8 psi
Frost: On expansion valve, outlet of freezer plate 1, some of surface of Plate 1
Compressor to Condenser Temp: 150F
Condenser to Receiver Temp: 76F
Return line at exit of plate 2 TxBulb: 66F
Return Line at Compressor: 72F

Time 38 min
High Pressure: 86 psi
Low Pressure: 9 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, first inch of plate 2
Compressor to Condenser Temp: 174F
Condenser to Receiver Temp: 76F
Return line at exit of plate 2 TxBulb: 62F
Return Line at Compressor: 74F

Time 49 min
High Pressure: 89 psi
Low Pressure: 9.5 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, top half of plate 2
Compressor to Condenser Temp: 187F
Condenser to Receiver Temp: 76F
Return line at exit of plate 2 TxBulb: 57F
Return Line at Compressor: 72F

Time 70 min
High Pressure: 90 psi
Low Pressure: 10 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, top 5/8 of plate 2
Compressor to Condenser Temp: 204F
Condenser to Receiver Temp: 77F
Return line at exit of plate 2 TxBulb: 49F
Return Line at Compressor: 69F

Time 85 min
High Pressure: 88 psi
Low Pressure: 10 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, top 3/4 of plate 2
Compressor to Condenser Temp: 210F
Condenser to Receiver Temp: 78F
Return line at exit of plate 2 TxBulb: 29F
Return Line at Compressor: 66F

Time 99 min
High Pressure: 87 psi
Low Pressure: 10 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, top 3/4 of plate 2
Compressor to Condenser Temp: 215F
Condenser to Receiver Temp: 78F
Return line at exit of plate 2 TxBulb: 12F
Return Line at Compressor: 60F

Time 112 min
High Pressure: 87 psi
Low Pressure: 10 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, 70% of plate 2 surface
Compressor to Condenser Temp: 216F
Condenser to Receiver Temp: 76F
Return line at exit of plate 2 TxBulb: 7.8F
Return Line at Compressor: 57F

Time 129 min
High Pressure: 86 psi
Low Pressure: 10 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, 70% of plate 2 surface
Compressor to Condenser Temp: 218F
Condenser to Receiver Temp: 76F
Return line at exit of plate 2 TxBulb: 7.2F
Return Line at Compressor: 49F

Time 141 min
High Pressure: 86 psi
Low Pressure: 10 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, 70% of plate 2 surface, Frost on return line 15 feet out of box (first point exposed), suction line sweating at compressor (before heat exchanger)
Compressor to Condenser Temp: 219F
Condenser to Receiver Temp: 76F
Return line at exit of plate 2 TxBulb: 6.8F
Return Line at Compressor: 40F

Time 159 min
High Pressure: 84 psi
Low Pressure: 9.5 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, 80% of plate 2 surface, suction line, check valve in suction line 3' from compressor), frost on suction line as comes onto compressor pallet
Compressor to Condenser Temp: 217F
Condenser to Receiver Temp: 74F
Return line at exit of plate 2 TxBulb: 3.3F
Return Line at Compressor: 3.7F

Time 170 min
High Pressure: 82 psi
Low Pressure: 8.5 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, 80% of plate 2 surface, suction line, check valve in suction line 3' from compressor), frost on suction line as comes onto compressor pallet
Compressor to Condenser Temp: 217F
Condenser to Receiver Temp: 74F
Return line at exit of plate 2 TxBulb: 2.8F
Return Line at Compressor: 3.9F

Time 181 min
High Pressure: 80 psi
Low Pressure: 8.5 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, all of plate 2 surface, suction line, check valve in suction line 3' from compressor), frost on suction line as comes onto compressor pallet
Compressor to Condenser Temp: 216F
Condenser to Receiver Temp: 70F
Return line at exit of plate 2 TxBulb: 1.7F
Return Line at Compressor: 3.7F

Time 191 min
High Pressure: 80 psi
Low Pressure: 8.0 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, all of plate 2 surface, suction line, check valve in suction line 3' from compressor), frost on suction line as comes onto compressor pallet
Compressor to Condenser Temp: 216F
Condenser to Receiver Temp: 69F
Return line at exit of plate 2 TxBulb: 0.9F
Return Line at Compressor: 2.7F

Time 202 min
High Pressure: 78 psi
Low Pressure: 8.0 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, all of plate 2 surface, suction line, check valve in suction line 3' from compressor), frost on suction line as comes onto compressor pallet
Compressor to Condenser Temp: 217F
Condenser to Receiver Temp: 69F
Return line at exit of plate 2 TxBulb: 0.5F
Return Line at Compressor: 4.3F

Time 235 min
High Pressure: 76 psi
Low Pressure: 7.8 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, all of plate 2 surface, suction line, check valve in suction line 3' from compressor), frost on suction line as comes onto compressor pallet
Compressor to Condenser Temp: 216F
Condenser to Receiver Temp: 67F
Return line at exit of plate 2 TxBulb: 1.5F
Return Line at Compressor: 7.0F

Time 270 min
High Pressure: 75 psi
Low Pressure: 7.5 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, all of plate 2 surface, suction line, check valve in suction line 3' from compressor), frost on suction line as comes onto compressor pallet
Compressor to Condenser Temp: 215F
Condenser to Receiver Temp: 68F
Return line at exit of plate 2 TxBulb: 0.8F
Return Line at Compressor: 10F

Time 310 min
High Pressure: 75 psi
Low Pressure: 7.5 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, all of plate 2 surface, suction line, check valve in suction line 3' from compressor), frost on suction line as comes onto compressor pallet
Compressor to Condenser Temp: 212F
Condenser to Receiver Temp: 67F
Return line at exit of plate 2 TxBulb: 0.2F
Return Line at Compressor: 12F

>Also make note in the 90 minute test when thermostat stops compressor.

In a 5 hour run the plates did not get cold enough to shut down the compressor, temp of thermostat probe was 11F at 5 hours.

> Line temperature reported in Hot, Warm, Body temp, and cold.

> Actual temperatures of plates not needed till follow up fine tuning is done later.

[botanybay]

Thanks again for taking a look at the data, probably way more than is needed.

I will take a picture of the expansion valve when I am down at the boat and attach it.

I am planning on drawing up a schematic of the system which is better than the text version a couple of posts back and upload a scan of it.

[botanybay]

The prior post is the current data. This followup is just looking at a comparison of the end of test data taken a few days ago (June 2014) and incomplete data (no pressure guages) taken back in March 2012 when the system was functioning well. In both cases only the freezer circuit is active.

Note that I took these readings two years ago (before the fridge plate developed a leak and had to be removed) at the end of a long test run (no guages hooked up at that time).

Measured with a different IR temp guage from the current readings so there are probably differences.

This is the what the freezer did two years ago... (March 2012) -- Not what I see now
Freezer circuit only, fridge circuit turned off at the end of the cycle.
March 2012: Temp at Expansion Valve: -25F
March 2012: Temp at exit of freezer plate 1: -31F
March 2012: Temp at exit of freezer plate 2: -37F

Definitely very different than what I am seeing today. Unfortunately no pressure measurements were made back in 2012...

Current performance: Freezer circuit only, fridge circuit capped off after 310 minutes of run
June 2014: Temp at Expansion Valve: 1.3F
June 2014: Temp at exit of freezer plate 1: -3.6F
June 2014: Temp at exit of freezer plate 2: 0.2F

Data from prior post:
Current Data (June 2014)
Time 310 min
High Pressure: 75 psi
Low Pressure: 7.5 psi
Frost: On expansion valve, outlet of freezer plate 1, Plate 1, all of plate 2 surface, suction line, check valve in suction line 3' from compressor), frost on suction line as comes onto compressor pallet
Compressor to Condenser Temp: 212F
Condenser to Receiver Temp: 67F
Return line at exit of plate 2 TxBulb: 0.2F
Return Line at Compressor: 12F

[Richard Kollmann]

This revised data now simplifies the performance problem.

There is no frosted areas on high pressure side of system and complete system now is only a freezer with two plates.

Your data now shows two problem areas High pressure is too low and Low pressure is too high.

HIGH PRESSURE
Best performance is when high pressure with plates very warm is 115 to 135 psi. When plates are frozen completely high pressure could be as low as 90 psi. When seawater is used as a cooling medium for refrigeration there must be a way to regulate heat exchange in condenser in order maintain refrigerant pressures in the best performance range. Grunert and Crosby used and my own designs used a manual seawater bypass to regulate cooling water, others use a pump speed controller or restrictor. As a temporary solution you can close pump through hull a small amount to restrict flow until high pressure at 20 minutes after startup is around 110 to 115 psi. Larger marine refrigeration systems use a high refrigerant pressure to water flow regulator.

LOW PRESSURE.

Low pressures will vary with type of refrigerant used. Refrigerant low pressure for refrigerator with +26 degree F eutectic holding plates will be in a range of 6 to 10 psi, once frost starts to show up on plates. Freezer plates with a solution eutectic point of say +10 degrees F will have a pressure of from +1 to +6 psi if refrigerant is Freon R12 and two pounds higher if it is refrigerant 134a.

When and after making refrigerant flow adjustments keep an eye out for frost returning towards compressor.

After increasing high pressure and plates show signs of frost lower low pressure by turning EXV super heat screw clockwise in ½ turn and wait for pressure to stabilize before adjusting further. For freezer plate starting to frost exterior surface 6 psi might be a good trial setting. As plate solution freezes pressure will automatically drop. If suction pressure drops below 2 psi , I would open TXV valve slightly.

[botanybay]

I will give this a try this weekend and see where it gets me. I will post updated data over the weekend.

One question I have is since I had a plate go bad, (leaking refrigerant into utectic solution which then pushed the solution out of the plate) is there any concern with "incompressibles" (like air) having gotten into the system and impacting system performance?

I think it is unlikely as the system appears to not go into a negative pressure regime and the check valve/solenoid on the fridge side kept the entire system from venting through the plate.

It is more a nagging question in the back of my head while I am working on the system.

Thank you very much for your help!

[botanybay]

Compressor High side output port
|
|-- High pressure cutout switch
|
|-- Stub with coil of what looks like a temp probe wrapped around it. Other end enters compressor
|
Salt water heat exchanger refrigerant inlet near salt water exit
|
Salt water heat exchanger refrigerant outlet near salt water inlet (i.e. refrigerant and salt water are counterflow)
|
High pressure Inlet of suction side to high side heat exchanger (same end as refrierant return from evaporator (holding plates)
|
High pressure outlet of suction side to high side heat exchanger (same end as low side to compressor)
|
High pressure receiver inlet
|
Rotolock on output of high pressure receiver (to isolate the dryer?)
|
High pressure side site glass
|
High pressure rotolock port (to isolate the dryer? and lock off the compressor pallet for shipping) has integral schrader valve high side test port
|
Solonoid for freezer side (there is a mirror fridge side with no plate installed)
|
15 feet of copper tubing
|
Freezer expansion valve on first plate
|
Plate 1 inlet port
|
Plate 1 exit port
|
Plate 2 Loop 1 inlet port
|
Plate 2 Loop 1 exit port
|
|- expansion valve sense bulb (on vertical part of tubing going up. near bottom, refrigerant flow from bottom to top)
|
Plate 2 Loop 2 inlet port
|
Plate 2 Loop 2 exit port
|
15 feet of copper tubing
|
Freezer side check valve (there is a mirror check valve for the fridge side with no plate installed)
|
Rotolock valve to seal off the compressor pallet for shipping. Test port on external side (currently measuring here)
|
Check valve on compressor pallet
|
Suction side inlet to high side heat exchanger (same end as high side coming from the salt water heat exchanger)
|
Suction side outlet to high side heat exchanger (same end as the high side going to the receiver)
|
Suction side inlet for compressor
|
Compressor body (with suction port schrader valve)
So there appears to be at least one switch (I assume a high pressure cutout switch?) but I don't see any indication of a low pressure cutout switch. One
could easily be added to one of the ports though.

[botanybay]

Pre-Experiment conditions:

Air temp 81F
Water temp 72F
Plates at room temperature (72F) Fridge down near waterline
Salt water flow restricted down to a thin stream by putting C-Clamp on output of water pump.

Time 0 min (before start)
High Pressure: 75 psi
Low Pressure: 72 psi
Frost: None anywhere (system is off)
Compressor to Condenser Temp: 72F
Condenser to Receiver line: 72F
Return line at exit of plate 2 TxBulb: 72F
Return Line at Compressor: 72F

Time 0.5 min
High Pressure: 95 psi
Low Pressure: 12 psi
Frost: None anywhere
Compressor to Condenser Temp: 74F
Condenser to Receiver line: 74F
Return line at exit of plate 2 TxBulb: 74F
Return Line at Compressor: 74F

Time 10 min
High Pressure: 85 psi
Low Pressure: 8 psi
Frost: expansion valve, exit plate 1 cool to touch
Compressor to Condenser Temp: warm
Condenser to Receiver line: body temp
Return line at exit of plate 2 TxBulb: room temp
Return Line at Compressor: slightly cool

Time 15 min
High Pressure: 85 psi
Low Pressure: 8 psi
Frost: expansion valve, exit plate 1 cool to touch
Compressor to Condenser Temp: warm = 132 F
Condenser to Receiver line: 77 F
Return line at exit of plate 2 TxBulb: 70 F
Return Line at Compressor: 80 F

Time 21 min
High Pressure: 90 psi
Low Pressure: 10 psi
Frost: expansion valve heavy frost, plate 1 sweating across surface, line from plate 1 to plate 2 sweating
Compressor to Condenser Temp: hot = 150 F
Condenser to Receiver line: 78 F
Return line at exit of plate 2 TxBulb: 70 F
Return Line at Compressor: 81 F

Time 31 min
High Pressure: 92 psi
Low Pressure: 10.5 psi
Frost: expansion valve heavy frost, plate 1 sweating across surface, line from plate 1 to plate 2 icing from sweat, plate 2 sweating
Compressor to Condenser Temp: hot = 175 F
Condenser to Receiver line: 80 F
Return line at exit of plate 2 TxBulb: 68 F
Return Line at Compressor: 82 F

[botanybay]

Pre-Experiment conditions:

Air temp 81F
Water temp 72F
Plates at room temperature (72F) Fridge down near waterline
Salt water flow restricted down to a thin stream by putting C-Clamp on output of water pump.
32 min of run at test case #1 prior to adjust

Time 42 min
Action - Adjust TXV 1/4 turn CCW
All looks ok, no significant changes

Time 44 min
Action - Adjust TXV 1/4 turn CCW (1/2 turn total)
All looks ok, no significant changes

Time 47 min
Action - Adjust TXV 1/2 turn CCW (1 turn total)
All looks ok, top of second plate (first inch) turned to ice after a minute.

Time 50 min
High Pressure: 98 psi (up from 92 psi prior to adjust)
Low Pressure: 13 psi (up from 10.5 psi prior to adjust)
Frost: expansion valve heavy frost, plate 1 sweating across surface, line from plate 1 to plate 2 icing from sweat, plate 2 sweating, 1/4 of top of plate 2 frosted
Compressor to Condenser Temp: hot = 202 F
Condenser to Receiver line: 82 F
Return line at exit of plate 2 TxBulb: 62 F
Return Line at Compressor: 88 F (Suction line near pallet 76 F)

Time 60 min
High Pressure: 100 psi
Low Pressure: 13.5 psi
Frost: all above + Plate 1 sweat turned to ice across surface
Compressor to Condenser Temp: hot = 214 F
Condenser to Receiver line: 81 F
Return line at exit of plate 2 TxBulb: 56.5 F
Return Line at Compressor: 92 F (Suction line near pallet 75 F)

Time 70 min
High Pressure: 100 psi
Low Pressure: 13.5 psi
Frost: all above + lines of ice 1/2 way down plate 2, lines of sweat 2/3 of way down plate 2
Compressor to Condenser Temp: hot = 220 F
Condenser to Receiver line: 84 F
Return line at exit of plate 2 TxBulb: 50 F
Return Line at Compressor: 96 F (Suction line near pallet 72 F)

Time 80 min
High Pressure: 103 psi
Low Pressure: 14 psi
Frost: all above + plate 2 shows coil frost lines all down plate, plate 1 has sweat ice but no frost
Compressor to Condenser Temp: hot = 222 F
Condenser to Receiver line: 84 F
Return line at exit of plate 2 TxBulb: 42 F
Return Line at Compressor: 96 F (Suction line near pallet 72 F)

Time 90 min
High Pressure: 103 psi
Low Pressure: 14 psi
Frost: all above + plate 2 shows coil frost lines all down plate, plate 1 has sweat ice but no frost, ice not well attached to plate. Temp of salt water output feels cool
Compressor to Condenser Temp: hot = 235 F
Condenser to Receiver line: 84 F
Return line at exit of plate 2 TxBulb: 18 F
Return Line at Compressor: 97 F (Suction line near pallet 67 F)

Time 100 min
High Pressure: 102 psi
Low Pressure: 14 psi
Frost: all above
Compressor to Condenser Temp: hot = 241 F
Condenser to Receiver line: 84 F
Return line at exit of plate 2 TxBulb: 17.8 F
Return Line at Compressor: 98 F (Suction line near pallet 64 F)

Compressor shut down, all pressures good, temp is getting rather hot, sounded like internal relay lifting. Thermostat shows run light. Allowing to cool for several hours prior to attempting a restart (it did restart just fine later)

[botanybay]

Pre-Experiment conditions:

Air temp 81F
Water temp 72F
Plates partially frozen (2.5 hours after prior test)
Salt water flow UNrestricted (Full flow)
Mostly to verify no ill effects of shutdow.
TXV setting 1/2 turn CW from original position (increasing superheat, reducing refrigerant flow) - Clockwise measured from looking at screw, as this faces down it can be confusing...

Time 0 min
Compressor on, sounding fine
Note that plates are partially frozen (Ice has melted off the the plate faces)

Time 0.5 min
High Pressure: 105 psi
Low Pressure: 8 psi
Frost:
Compressor to Condenser Temp: warm = 120 F
Condenser to Receiver line: 83 F
Return line at exit of plate 2 TxBulb: 39.2 F
Return Line at Compressor: 87 F (Suction line near pallet 57 F)

Time 10 min
High Pressure: 95 psi
Low Pressure: 7 psi
Frost: expansion valve and exit line out of first plate
Compressor to Condenser Temp: warm = 133 F
Condenser to Receiver line: 83 F
Return line at exit of plate 2 TxBulb: 40.1 F
Return Line at Compressor: 89 F (Suction line near pallet 64 F)
expansion valve temp is -5.3F, line into first plate is -7F

Time 14 min
High Pressure: 94 psi
Low Pressure: 8 psi
Frost: all above + face of plate 1 is iced, line between plates is frosted, first inch of plate 2 is iced
Compressor to Condenser Temp: hot = 172 F
Condenser to Receiver line: 80 F
Return line at exit of plate 2 TxBulb: 38.8 F
Return Line at Compressor: 92 F (Suction line near pallet 65 F)

Time 20 min
High Pressure: 95 psi
Low Pressure: 8 psi
Frost: all above
Compressor to Condenser Temp: hot = 178 F
Condenser to Receiver line: 81 F
Return line at exit of plate 2 TxBulb: 38.4 F
Return Line at Compressor: 93 F (Suction line near pallet 65 F)

Time 30 min
High Pressure: 95 psi
Low Pressure: 8 psi
Frost: all above + top 2 inches of plate 2 is frosted
Compressor to Condenser Temp: hot = 192 F
Condenser to Receiver line: 80 F
Return line at exit of plate 2 TxBulb: 37.5 F
Return Line at Compressor: 98 F (Suction line near pallet 65 F)
plate 1 is about 8F, plate 2 top is 16F

Time 46 min
High Pressure: 92 psi
Low Pressure: 8 psi
Frost: all above
Compressor to Condenser Temp: hot = 197 F
Condenser to Receiver line: 80 F
Return line at exit of plate 2 TxBulb: 36.3 F
Return Line at Compressor: 101 F (Suction line near pallet 66 F)

Action: Adjust TXV 1/2 turn clockwise (increasing superheat) total 3/4 turn from original setting

Time 60 min
High Pressure: 92 psi
Low Pressure: 4.5 psi
Frost: all above
Compressor to Condenser Temp: hot = 162 F
Condenser to Receiver line: 82 F
Return line at exit of plate 2 TxBulb: 36.5 F
Return Line at Compressor: 116 F (Suction line near pallet 71 F)

Time 70 min
High Pressure: 100 psi
Low Pressure: 3.5 psi
Frost: all above
Compressor to Condenser Temp: hot = 92 F (huge drop!!!)
Condenser to Receiver line: 82 F
Return line at exit of plate 2 TxBulb: 38 F
Return Line at Compressor: 140 F (Suction line near pallet 78 F)

Compressor shut down! Case temperature was 222 F

Returned TXV back to original position (i.e. turned 3/4 turn CCW) back to the default position.

[botanybay]

Pre-Experiment conditions: Mostly to verify no ill effects of shutdow.

Air temp 81F
Water temp 72F
Plates partially frozen (1.5 hours after prior test)
Salt water flow UNrestricted (Full flow)
TXV default postion, then three steps of 1/8 CW from original position (increasing superheat, reducing refrigerant flow) - Clockwise measured from looking at screw, as this faces down it can be confusing...

Time 0 min
Compressor on, sounding fine
Note that plates are partially frozen (Most Ice has melted off the the plate faces)

Time 0.5 min
High Pressure: 100 psi
Low Pressure: 12 psi
Frost:
Compressor to Condenser Temp: warm = 154 F
Condenser to Receiver line: 84 F
Return line at exit of plate 2 TxBulb: 28.3 F
Return Line at Compressor: 86 F (Suction line near pallet 66 F)

Time 10 min
High Pressure: 92 psi
Low Pressure: 11 psi
Frost: stationary bubble in sight glass, glass half full
Compressor to Condenser Temp: warm = 179 F
Condenser to Receiver line: 84 F
Return line at exit of plate 2 TxBulb: 11.5 F
Return Line at Compressor: 83 F (Suction line near pallet 56 F)

Time 20 min
High Pressure: 90 psi
Low Pressure: 10.5 psi
Frost: return line (suction) is frosting inside the box
Compressor to Condenser Temp: hot = 191 F
Condenser to Receiver line: 78 F
Return line at exit of plate 2 TxBulb: 10.1 F
Return Line at Compressor: 87 F (Suction line near pallet 54 F)

Time 30 min
High Pressure: 88 psi
Low Pressure: 10.3 psi
Frost:
Compressor to Condenser Temp: hot = 199 F
Condenser to Receiver line: 76 F
Return line at exit of plate 2 TxBulb: 10.1 F
Return Line at Compressor: 86 F (Suction line near pallet 52 F)

Action: Intended to go 1/8 turn CW (more superheat, less refrigerant), however, went the wrong way and ended up 1/8 CCW (less superheat, more refrigerant)
Position: 1/8 turn CCW from default

Time 40 min
High Pressure: 88 psi
Low Pressure: 10.7 psi
Frost:
Compressor to Condenser Temp: hot = 192 F
Condenser to Receiver line: 76 F
Return line at exit of plate 2 TxBulb: 10.1 F
Return Line at Compressor: 85 F (Suction line near pallet 51 F)

Action: Return TXV to default position (CW 1/8)
Position: Default position

Time 50 min
High Pressure: 87 psi
Low Pressure: 10.3 psi
Frost: all above
Compressor to Condenser Temp: hot = 213 F
Condenser to Receiver line: 78 F
Return line at exit of plate 2 TxBulb: 10.1 F
Return Line at Compressor: 94 F (Suction line near pallet 47 F)

Action: Adjust TXV CW 1/8 turn
Position: CW 1/8 turn from default

Time 60 min
High Pressure: 86 psi
Low Pressure: 10.3 psi
Frost: all above + Suction line near compressor pallet
Compressor to Condenser Temp: hot = 213 F
Condenser to Receiver line: 75 F
Return line at exit of plate 2 TxBulb: 9.9 F
Return Line at Compressor: 89 F (Suction line near pallet 0 F)

Action: Adjust TXV CW 1/8 turn
Position: CW 1/4 turn from default

Time 66 min
High Pressure: 84 psi
Low Pressure: 10 psi
Frost:
Compressor to Condenser Temp: hot = 219 F
Condenser to Receiver line: 73 F
Return line at exit of plate 2 TxBulb: 8.8 F
Return Line at Compressor: 84 F (Suction line near pallet 3.5 F)

Time 73 min
High Pressure: 84 psi
Low Pressure: 9.5 psi
Frost:
Compressor to Condenser Temp: hot = 223 F
Condenser to Receiver line: 74 F
Return line at exit of plate 2 TxBulb: 8.5 F
Return Line at Compressor: 90 F (Suction line near pallet 6.6 F)

Time 80 min
High Pressure: 82 psi
Low Pressure: 9.5 psi
Frost: On check valve on the pallet, prior to heat exchangers
Compressor to Condenser Temp: hot = 222 F
Condenser to Receiver line: 73 F
Return line at exit of plate 2 TxBulb: 8.5 F
Return Line at Compressor: 87 F (Suction line near pallet 9.7 F)

Terminated run, frost on the pallet prior to the high side / low side heat exchanger

Returned TXV to 1/8 CW from default as starting point for next run tomorrow