Is there an easy way to refill holdover plates with Eutectic solution

[phorvati]

Originally Posted by OzeLouie

To condense the findings:
Problem: Compressor wont start unless a few seconds of gas is purged.

Observations: (Assuming the problem is not a power supply issue!!)

if the problem was power supply, why is it that I have to let out refrigerant from suction side to get it going again? And how do I troubleshoot power supply? I can put a scope on the voltage to see how far it droops.

Originally Posted by OzeLouie

A) High side pressure at 60 to 70 PSIG.

more like 100-105 Psi when glass is 1/2 full and air cooling only. Last night it locked up again and i had to let out significant amount of refrigerant to get it to start again. as in 10 seconds or so.

Originally Posted by OzeLouie

B) Compressor only able pull down to 10" vacuum during test.
C) Once started system runs to refrigerates to cut off temp.
D) No report of compressor noise or sweating once started and running.

What the problem is not:
A) It is definitely not due to a shortage of refrigerant gas. Short of gas allows for easier compressor start up, not harder!!
B) It is definitely not due to a discharge line restriction as once started it runs and refrigerates.
C) It is not flooding refrigerant into compressor via the suction as this would require a lot of liquid refrigerant, a lot of purging to get the reported start relief and there would be signs of cooling / sweating of the compressor sump when started and initial running. It would take many ounces to flood that compressor sump sufficiently to fill compression chamber and lock it up.

So I have a web cam on the thermostat so i can keep an eye on it while i'm at work. Ive been observing my cycling since the last lockup tuesday morning. Its set at 11F with 3F differential since monday night. It runs about 4-5 times per day and Ive been seeing temperatures in the 11-14F just as intended. It reaches 11F set point within few hours. SO perfect.

After last nights lockup 10PM EDT, and having to let out significant amount if refrigerant to get it started, thermostat is at 18F. It was 14F when it locked up. So it ran all night and it went from 14F to 18F. 8AM EDT. Seems to be low on refrigerant.

Originally Posted by OzeLouie

Conclusions:
A) The compressor most likely has a damaged discharge valve reed as vacuum test indicated. Suction valve reed is ok as indicated by compressor holding vacuum when off after test. Head gasket is also ok.
B) Head pressure is far too low (Over- condensing) as I reported several times. Needs to be approx 120 PSIG.
C) During a long off cycle high side refrigerant is able to dribble 'backwards' into compressors compression chamber via defective discharge reed to where it condenses into small amount of liquid refrigerant, sufficient to prevent the pistons free movement. (May be less than an ounce!)

Not so sure after last nights lockup, I let out more than few Oz of refrigerant.

Originally Posted by OzeLouie

Suggestions:
A) Fit digital thermostat with probe imbedded between the near top fins of the air cooled condenser. With high side gauge to observe, set SET (cut in) to cause condenser fan / pump to start at 125PSIG and HYS to cause off at 115PSIG. (This alone may overcome start problem as higher head pressure applies greater closing pressure on the discharge reed.)
B) Ideally replace compressor but the existing may still run for years even with defective discharge reed (Fingers crossed!!!)
C) Having completed above, run system, adjust TEV and top up refrigerant.

So both air fan and water pump not running until 125PSI. Sounds good.

The only issue I have is, everything Ive learned is that if i put more refrigerant, more dribbles back during off state to lock it up. Its almost like dont let it stop, and if it stops dont let it stop for long time as that's when refrigerant dribbles back.

I have my finger on replacement compressor.

[Richard Kollmann]

I fear that this last test is but one more smaller circle of the well known Oozlum Bird.

Why replace compressor because of a start problem now not reed valve or unidentified induction relay or start run capacitor question. Through in another circle for over size TXV because excessive flow on start will result in an overload.

[phorvati]

So I reverted back the txv. CW back to original setting.

I have sporlan FJ1/4-c
I don't know the orifice size but
F: flare fittings 1/2" out and 1/4" in
J: R134-a
1/4: quarter ton
C: bulb charge commercial refrigeration 50F to -10F

I would love to eliminate electrical from possible reason for overloaded start, 40A draw, and breaker tripping. Why letting out refrigerant from suction side allows it to start again and how can that resolve the electrical issue.

[Richard Kollmann]

Originally Posted by phorvati

So I reverted back the txv. CW back to original setting.

I have sporlan FJ1/4-c
I don't know the orifice size but
F: flare fittings 1/2" out and 1/4" in
J: R134-a
1/4: quarter ton
C: bulb charge commercial refrigeration 50F to -10F

I would love to eliminate electrical from possible reason for overloaded start, 40A draw, and breaker tripping. Why letting out refrigerant from suction side allows it to start again and how can that resolve the electrical issue.

As I understand these overloads do not happen on every start. We also do not know if the thermostat differential off cycle is long enough to allow pressures equalization.

The 1/4 ton TXV should be OK although I prefer a slightly smaller orifice (capacity)
It is not unusual for source power like from marine facilities to have voltage drop during compressor starts.
We also know your system has excessive refrigerant storage in liquid side of system.
It is also a fact that this type compressor exhilarates to operating Rpm very fast speeding up low side pump down process on start.

I would propose because eutectic plate systems are not intended to be cycling compressors that resetting thermostat differential to ten or fifteen minutes.
Then if the overload condition still is a problem lets try the solution used on old compressors by piggy back a correct kick start capacitor to slow start compressor, available from United refrigeration or wwwGranger.

[Coolerking]

Just get a 3 in 1 hard start kit and a check valve on the suction line and end this nightmare! ��������

[Richard Kollmann]

Originally Posted by Coolerking

Just get a 3 in 1 hard start kit and a check valve on the suction line and end this nightmare! ��������

Why a check valve in suction line, Louie theory is high pressure reed valve possible failure do to a crack.

[Coolerking]

I was just thinking, if he has a liquid line solenoid , and a check valve, then all his liquid migration issues might be solved.
Also, has he considered converting the control to a pump down system?

[OzeLouie]

Best not to function the eutectic system as you would a cyclic system, operating more often but still without reference to refrigerant pressures.
I notice you have now fitted a freezer liquid line solenoid so you could easily convert to the ultimate refrigeration system function control.... pump down, as I mentioned earlier in this thread. You have a high side pressure switch but will have to also add a low side pressure switch to achieve this.
To do this only power your compressor via those two pressure switches and in series. Each cabinets thermostat would only power relative solenoid on / off.
Set HP at 225PSIG open close at 150. Set low side switch to open 2 to 3 PSI below run cycle pressure and close at say 20 PSIG. This will ensure that the suction side including compressor are vapour only on start up and has the added benefit of flushing the evaporator coils at each run. This would also aid the boiling off of suspected condensed refrigerant laying in the compression chamber similar to the purging you do to allow start up.
Also fit the thermostat to condensers as described to raise head pressure, then proceed to fine tune refrigerant charge and TEV settings

Reference to power supply and suggestions for the non start remedy are provided based on information supplied. Poor power supply is the most common cause of, or contributes to, system failure issues.

Regards:
Originally Posted by OzeLouie View Post
A) High side pressure at 60 to 70 PSIG.
more like 100-105 Psi when glass is 1/2 full and air cooling only. Last night it locked up again and i had to let out significant amount of refrigerant to get it to start again. as in 10 seconds or so.

My reference was based on your earlier report and I notice you don't appear to have tested with the high side to 120 PSIG as suggested. As stated earlier increasing the high side puts greater back pressure on the discharge reed and this may actually reduce the suspec6ted backflow. We cant visualize the discharge reed but using info supplied it most likely only has miner damage or 'bruising in which case added back pressure may help to seat it closed during off cycle.

Finally: The many reports and suggestions you are receiving here are derived from information provided and considering that this system is obvious not engineered, we have no access to it, it is the best we can all come up with to try and help you. The suggestions I and most others have made are based on industry recognised procedures, but its not simple. Suggest you figure out who is trying to assist you with tests to try and detailed explanations etc and who is using your dilemma to grandstand with unsupported waffle and childish snipes at others.


Sorry CoolerKing I didn't notice your last post until after posting mine. Agree pump down is now a good option.

[Richard Kollmann]

I see a lot of words, shovels full, but no real supportable true proven examples of correct solutions. Don't you worry about the industry experts who follow this forum as well as others wanting to ask for kelp but won't get involved think of this confusing foolishness. Talk about Goldberg turning a mole hole into a mountain of unrelated useless theories.

One more point of confusion is their is a big difference between energy storing plates like this cast aluminum true holdover plates are where compressor runs till plate is completely frozen. What you find today in pleasure boats are smaller eutectic plates that must be cycled many times per day and operate the same as any thin plate evaporator with an equal K value heat energy transfer.

[Coolerking]

Ok guys, I will gracefully bow out of this one.
Let me know how it turns out.

[OzeLouie]

Originally Posted by Coolerking

Ok guys, I will gracefully bow out of this one.
Let me know how it turns out.

Me too, now I know why my mentor and other industry people avoid and advised against trying to be helpful at this forum.

[Richard Kollmann]

Hopefully now we can forget about text book engineering when it comes to mobile boat refrigeration. Almost every one of our ice box conversion refrigeration systems violates one or more engineering refrigerant standard because there are no installation exactly the same. Engineering standards would never permit oil to be trapped in low pressure lines. Nor would they want to use unequal components in a system. Do you think small compressor manufacturers include any form of water cooling in their engineering application sheets. I was hired to spend two weeks in the West Indies training six mechanics from three companies about boat refrigeration. Mornings in class room where we assembled a functioning complete system using 25 ft of ¼ copper tubing a bucket, compressor out of a dorm refrigerator, parts and large dogs water bowl as a water to ice evaporator.

The refrigeration system in this long trouble thread is not new nor is it simple or would it be considered text book engineered. From what we know so far there is nothing inherently wrong calling for an engineering change of the hermetically sealed compressor or refrigeration system.
Normal functions of this operating system needs to be documented so fine toning adjustment can be done..
1. Compressor starts and runs but not every time. The question is this a lock up Rotor condition or electrical power shortage? Start relay and compositors are at question. Coolerking experienced engineer suggest a replacement three way kick start kit to replace compressor starting hardware.(No one disagreed) I also suggested extending thermostat’s off cycle time to 10 minutes, SEE post 79.

2. When compressor has run the box with aluminum SeaFrost plate gets cold.
3. No information on exact low pressures. Normal low pressure after 10 minutes compressor running is expected to be 20 psi to 8 psi , super heat not adjusted yet. If thermostat allows compressor to run 30 minutes low pressure will be less than it was at 10 minutes. If compressor is run an hour or till plate solution is frozen low pressure will be 6 psi or less. At no time should frost on return line extend towards compressor. On day where temperatures is below 70 degree F the horizontal sigh glass should not be full. Always record pressure readings and frosted areas.
4. Knowing high pressure and duration on moment of start is help full. Start amperage and duration above 19 amps is of major interest. High pressure after 10 minutes will result from how well condenser cooling medium is in removes heat. In cold weather expect pressure as low as 95 psi. In 100 degree ambient conditions 135 psi. Unless there is fan air cooling compressor pressures may exceed 135 psi this will shorten compressor’s lifespan. It must be understood that most compressor cooling comes from cool refrigerant returning from evaporator. Sixty degree return line temperature is desirable but on this system not normally available.

If you provide the test pressures and running time recorded along with frost line and sight glass levels any experienced tech with eutectic plate operation experience can assist you in balancing system. Maybe Coolking will come back to assist. With his help and no more alterations to design things may lookmuch better.

[phorvati]

This is crazy, I just want my 110v fridge to work and not to have to let out refrigerant out of suction side every 2-3 days. Then add half a can just to get it back to keeping that ice cream not mushy. I sound a bit spoiled, but if kids are happy, wife is happy and then I can sip my rum drink and relax. And it is an ultimate challenge, solid frozen ice cream.
I'll buy new compressor, but this would be the third compressor in 3 years, granted I added suction line accumulator and new txv since the last compressor a year ago so I can't say if legitimate floodback ruined this compressor.
What's going to happen when I add the engine drive to this. Rich beers designed a Tecumseh hg850 based engine drive that was here and was neglected which I intend to just replicate. Both cold plates have dual coils so it's just a matter of getting the same parts and pressure testing the lines.
Anyhow, I'd like to eliminate posibility that reed valve is letting liquid into chamber and thats how my suction side goes from vacuum to 25psi during off time. I know if I add more refrigerant to get to 120psi and 3/4 sight glass, stall happens every time. Not every 2-3 days. If I let out too much, I'm sitting at 20+F in the freezer. I added a solenoid in liquid line next to filer/sight glass to prevent liquid moving, But the stall condition is still happening. And again how can it be electrical if i have to let refrigerant out and then it works. The more feedback I read the more I think it might not be a compressor.
Unfortunately I also added additional blue board insulation under the box and plugged up the drain holes and i added new lid seal so I reduced runtime, which kind of hurts me. It gives liquid more time to flood the chamber, whichever way it gets there.
At some point I'm going to get off the dock for few weeks and I'm not going to want to run the northern lights 24/7.
I guess I better get the new nitrogen tank and start putting together the engine drive.

[Uncle Bob]

Originally Posted by phorvati

This is crazy, I just want my 110v fridge to work and not to have to let out refrigerant out of suction side every 2-3 days. Then add half a can just to get it back to keeping that ice cream not mushy. I sound a bit spoiled, but if kids are happy, wife is happy and then I can sip my rum drink and relax. And it is an ultimate challenge, solid frozen ice cream.
I'll buy new compressor, but this would be the third compressor in 3 years, granted I added suction line accumulator and new txv since the last compressor a year ago so I can't say if legitimate floodback ruined this compressor.
What's going to happen when I add the engine drive to this. Rich beers designed a Tecumseh hg850 based engine drive that was here and was neglected which I intend to just replicate. Both cold plates have dual coils so it's just a matter of getting the same parts and pressure testing the lines.
Anyhow, I'd like to eliminate posibility that reed valve is letting liquid into chamber and thats how my suction side goes from vacuum to 25psi during off time. I know if I add more refrigerant to get to 120psi and 3/4 sight glass, stall happens every time. Not every 2-3 days. If I let out too much, I'm sitting at 20+F in the freezer. I added a solenoid in liquid line next to filer/sight glass to prevent liquid moving, But the stall condition is still happening. And again how can it be electrical if i have to let refrigerant out and then it works. The more feedback I read the more I think it might not be a compressor.
Unfortunately I also added additional blue board insulation under the box and plugged up the drain holes and i added new lid seal so I reduced runtime, which kind of hurts me. It gives liquid more time to flood the chamber, whichever way it gets there.
At some point I'm going to get off the dock for few weeks and I'm not going to want to run the northern lights 24/7.
I guess I better get the new nitrogen tank and start putting together the engine drive.

Hi, feel your pain but now that Richard has the floor it will be interesting if he can solve the dilemma, or as has happened in the past, he has other projects and has to move on.

[Richard Kollmann]

Originally Posted by Uncle Bob

Hi, feel your pain but now that Richard has the floor it will be interesting if he can solve the dilemma, or as has happened in the past, he has other projects and has to move on.

Uncle Bob, phorvati is his own worst enemy by going down one wrong rabbit hole after another not following good advice and changing system design too many times. Bob, you are correct my own plate is full with my wife of 68 years passing a few days ago. Coolerking and myself have good non destructive advice which he ignores taking the wrong advice.. The solutions to the electric refrigeration system are simple testing to isolate and fix problem forgetting the compressor itself foolishness.

As to the existing engine driven well engineered Rich Bears system I suspect it is repairable after clean up and refitting a second generation five cylinder swash plate compressor and smaller size drive pulley. The industry standards thirty years ago were to use high compressor Rpm. We now know after thousands of compressors failures this was a mistake. Another improvement in compressors is the clutch drive loads are now carried by body of compressor extending shaft seal life,