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[Solved] The principle of operation of the refrigerator, aological explanation, consequen

Starterek85 43440 12
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  • #1 17398646
    Starterek85
    Level 16  
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    Hello, I would like to start my adventure with refrigerators, as I was interested in building a fridge after purchase.
    Well, the fridge is Liebheer KGT 3946 on the R600a.
    The fridge is high, so unfortunately I decided to transport lying down.
    And here people have different opinions.
    Some of that on the suction side, others that the press and the admin AGD writes that it does not matter, until the refrigerator is not "upside down".
    As this refrigerator has two compressors and unfortunately set up oppositely, there was no choice, you had to choose one of two - a necessary evil.
    I bought the fridge, I could not check it, it was already turned off, the freezer was still cold (already defrosted), but the fridge was not.
    Well, but to the point. After transport to the destination and waiting 24 hours, the refrigerator was connected to the network.
    The effect is that both compressors turn on (both are very hot), the super cooler freezes, the wires coming out of the compressor also and the heat sink on the back of the refrigerator responsible for the freezer too.
    However, the compressor responsible for the fridge also works hot, but the wires coming out of it are not. It seems to me that the cooling wall inside the refrigerator is slightly colder than the inside of the refrigerator.
    The fridge is cool and I would like to experiment with it.
    I would like to ask you in what order and what to diagnose.
    I have some experience in air conditioning, I have a vacuum pump, pressure gauges, and a brazing kit.
    I add a picture of the compressors, I will add that the refrigerator was transported on the left side looking from the back, because this side was already scratched (most likely from the previous transport by the previous owner).
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  • #2 17399377
    bubu64
    Level 22  
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    There may be a loss in the refrigerator system or a stuck system, check it and since you have time, check the tightness of the nitrogen system :)
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  • #3 17400955
    Starterek85
    Level 16  
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    Cavity I understand that let R600A, but how do you check the stuffing? Capillary will be suppressed?
    I corrected TONI_2003
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  • #4 17400997
    jack63
    Level 43  
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    Starterek85 wrote:
    The cavity I understand that let r600a, a
    No.
    bubu64 wrote:
    check it and since you have time to check the tightness of the system with nitrogen :)
    Yes.
    Starterek85 wrote:
    I have some experience in air conditioning,
    A bit, and it's probably exaggerated.
  • #5 17409845
    Starterek85
    Level 16  
    Posts: 546
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    Small update:
    Termik compressor turns off and on very often, work and pause 3-4min. I understand that through the clogged system the intensity of the motor increases and the thermostat protects, the evaporator in the refrigerator is slightly cool.
    Now, yes, the capillaries, or the whole systems are clogged up?
    Desoldering the compressor and blowing on the 50bar nitrogen side is enough to break the system? Then it is soldered back, gives the medium according to the plate and works?
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  • #6 17409883
    jack63
    Level 43  
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    Starterek85 wrote:
    I understand that through the clogged system the intensity of the motor increases and the thermostat protects, the evaporator in the refrigerator is slightly cool.

    It may be so, but it may be that the compressor has finished its life.
    Starterek85 wrote:
    Desoldering the compressor and blowing on the 50bar nitrogen side enough to break the system?

    You will blow the condenser or steam trap and the capillaries will not slip if it is clogged ...
  • #7 17410891
    Starterek85
    Level 16  
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    I will drop the R600A, see if the compressor then works, if the klixon does not react. If the order remains, replace the capillary and refill the system. Someone on the forum wrote that the oil embolism at the R600A can just be blown with nitrogen, and someone even wrote that with the R600A the compressors are dealing with oil capillaries themselves. I've never had this with it, so I do not know. Besides, what a nonsense with these capillaries, after all the compressor spits oil in itself, then why the capillary does not get clogged?
  • #8 17410943
    jack63
    Level 43  
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    Starterek85 wrote:
    Someone on the forum wrote that the oil embolism at the R600A could just be blown with nitrogen, someone even wrote that with the R600A, the compressors cope with the oil capillaries themselves.
    What oil congestion and where would it take? After all, when the refrigerator is in the refrigerator, the oil from the compressor can only flow towards the evaporator and should be returned again after refitting.
    Systems with R600a, due to low work pressures are currently made of "paper". Therefore, treating them with nitrogen under high pressure can cause damage.

    The capillary permeability can be checked with nitrogen. Just think ... As it is clogged not so much by oil, but by the smell of salty oil from a superheated compressor, only the exchange remains. If such exchange is possible at all. The R600a compressor engines are very weak! This is another charm of this factor and a place for "savings" for producers. Overcharging or a small blockage stop the engine ...
    Starterek85 wrote:
    I will drop the R600A, see if the compressor then works, if the klixon does not react.
    How do you want to do it? Was there a Schrader valve?
  • #9 17410970
    Starterek85
    Level 16  
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    The principle of operation of the refrigerator, aological explanation, consequen
    Is it a pretty old fridge and probably of the more expensive ones, so it can withstand? There is no valve for the present. This is what the compressors look like. The right is from the fridge, which does not demand, the left is from the freezer. The fridge rode looking at the compressors on the left side.
  • #10 17411070
    jack63
    Level 43  
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    Starterek85 wrote:
    However, the compressor responsible for the fridge also works hot, but the wires coming out of it are not.
    If there was an embolism, then the pressure pipe should be very hot, and the sucking heat and according to I'm leaking. The fridge probably did not work properly before the purchase, and the transport of heating the system, the process of escaping the factor accelerated. Check the capillary outlet from the filter. Something terribly bent looks like?
  • #11 17411129
    Starterek85
    Level 16  
    Posts: 546
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    Well, it's bent, and if it's not good, I do not know. I have to solder the valve, pull the vacuum and check for leaks, can I vacuum or do I need nitrogen? Then I'll check if the compressor is still overheating klixon. If the compressor has too much resistance without the refrigerant, it is probably a compressor to be replaced. Well, it will not be seen until next week. If necessary, I will replace the compressor, because the refrigerator looks solid.
    I corrected TONI_2003
  • #12 17411176
    jack63
    Level 43  
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    Starterek85 wrote:
    I have to solder the valve, pull the vacuum and check the tightness, can I vacuum or do I need nitrogen?

    First a vampire and a vacuum. Then nitrogen to push butane, and finally soldering.
    Then "small" nitrogen and vacuum again. Then nitrogen about 6 -8 Bar and wait 24 hours on manometers.
    As it is ok, it will drain the nitrogen to about 0.5 Bar and turn on the compressor. Look what's going on.
    Turn off the compressor and continue to look, think and draw conclusions.
  • #13 19208127
    Starterek85
    Level 16  
    Posts: 546
    Help: 17
    Rate: 55
    Replacing the compressor, replacing the filter. Vacuum and charging the refrigerant, the refrigerator is operational, and the topic needs to be closed.

Topic summary

✨ The discussion revolves around troubleshooting a Liebheer KGT 3946 refrigerator that was transported lying down. Users express concerns about potential issues with the refrigeration system, including compressor overheating, possible blockages in the capillary system, and the effects of oil embolism with R600a refrigerant. Suggestions include checking the tightness of the nitrogen system, examining the capillary for clogs, and performing a vacuum and nitrogen pressure test to diagnose the problem. The conversation highlights the importance of proper handling during transport and the need for careful maintenance of the refrigeration system to ensure operational efficiency.
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FAQ

TL;DR: Use 6–8 bar nitrogen for tightness testing and "wait 24 hours" on the gauges to diagnose R600a fridge faults. This FAQ guides DIYers and techs to fix no-cool, short-cycling compressors, and capillary/leak issues after transport. [Elektroda, jack63, post #17411176]

Why it matters: It helps hands-on users quickly triage R600a systems without damaging delicate components.

Quick Facts

How do I tell if my R600a fridge has a leak or a capillary blockage?

Feel the lines. A blockage drives the discharge line very hot, with a warm suction. Cooler lines often suggest a leak. Inspect for kinks at the capillary’s exit from the filter-drier. That bend is a common choke point. If neither line heats normally, suspect insufficient charge. Confirm by adding a service port, then pressure test and observe. These temperature clues speed triage before invasive work. [Elektroda, jack63, post #17411070]

What nitrogen pressure should I use for leak testing on R600a refrigerators?

Pressurize with nitrogen to about 6–8 bar and hold for 24 hours. Watch the manifold for any drop. "Then nitrogen about 6–8 Bar and wait 24 hours." If pressure holds, evacuate and recharge. If it falls, locate leaks before charging. This approach protects thin R600a tubing and provides clear results. [Elektroda, jack63, post #17411176]

Can I clear a blockage by blowing 50 bar nitrogen?

Do not. "Systems with R600a, due to low work pressures are currently made of 'paper'." High pressure can rupture lines. Use modest nitrogen pressure only for testing. If the capillary is clogged by degraded oil, replace it and the drier. R600a compressors are weak; even small restrictions or overcharge can stall them. [Elektroda, jack63, post #17410943]

How do I safely purge and evacuate an R600a system before opening it?

Use a controlled method:
  1. Install a piercing (vampire) valve and pull vacuum.
  2. Purge with nitrogen to push out residual butane, then perform soldering.
  3. Pressurize to 6–8 bar nitrogen for 24 hours, then proceed with evacuation and charging. This sequence minimizes risk and verifies tightness before recharging. [Elektroda, jack63, post #17411176]

My compressor clicks off every 3–4 minutes (Klixon). What does that suggest?

Rapid thermal protector cycling indicates high motor load. Expect a refrigeration restriction or a failing compressor. Verify by checking line temperatures, then pressure-test and evacuate. Do not keep restarting under fault, as it overheats the motor. If tests show normal flow, suspect internal compressor wear. [Elektroda, jack63, post #17409883]

Where should I look first for physical restrictions or kinks?

Inspect the capillary right at the filter-drier outlet. Bends there can flatten and choke flow. Straighten only if gentle and accessible; otherwise plan replacement with a new drier. Also check the condenser path for dents and pinches. Prioritize visual checks before pressure procedures. [Elektroda, jack63, post #17411070]

Can I check capillary permeability with nitrogen before replacing it?

Yes. Flow test with nitrogen to confirm restriction. If it’s blocked by degraded oil from an overheated compressor, replacement is the fix. "The R600a compressor engines are very weak!" Even small restrictions or slight overcharge can stall them. Replace the drier whenever you open the circuit. [Elektroda, jack63, post #17410943]

After side transport, how long should I wait before powering a refrigerator?

If transported lying down, wait 24 hours before powering. This delay was used before first startup in this case. The pause helps avoid immediate faults from displaced fluids. It’s a common practice after side transport of household fridges. [Elektroda, Starterek85, post #17398646]

Do I need to add a service port to remove charge and test?

Yes. Install a piercing (vampire) valve to access the sealed system. Pull vacuum through it, then use nitrogen to purge the refrigerant and proceed with repairs. After soldering, repeat nitrogen pressurization and evacuation steps before charging. This adds control and safety to diagnostics. [Elektroda, jack63, post #17411176]

Will blasting nitrogen clear the condenser but not the capillary?

Correct. High flow can clear the condenser or a trap, but a truly clogged capillary usually stays blocked. Forcing it risks damage elsewhere. Confirm restriction with a nitrogen flow test. If blocked, replace the capillary and install a new drier. [Elektroda, jack63, post #17409883]

Should I replace the filter-drier whenever I open the circuit?

Yes. Replace the drier after opening the system to remove moisture and debris. In this case, a new compressor and drier, followed by evacuation and correct charge, restored function. Skipping the drier invites repeat restrictions and poor cooling. [Elektroda, Starterek85, post #19208127]

What fixed this exact Liebherr KGT 3946 that cooled poorly after transport?

The successful repair included replacing the compressor and the filter-drier. The tech then pulled a vacuum and charged with the specified refrigerant. The refrigerator returned to normal operation after this work. This outcome confirms both mechanical and flow path issues were resolved. [Elektroda, Starterek85, post #19208127]

What pressure should I leave in before a brief run test during diagnostics?

After a 24-hour nitrogen hold, vent down to about 0.5 bar. Then run the compressor briefly and observe behavior. "Drain the nitrogen to about 0.5 Bar and turn on the compressor." Use this controlled run to judge flow and motor load. Shut down and reassess findings. [Elektroda, jack63, post #17411176]
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