Breakage compressor often becomes an unpleasant surprise for the owner of household appliances, because this The unit is the heart of the entire cooling system. Without its correct operation, the required temperature in the chamber is no longer maintained, food begins to deteriorate, and an unpleasant odor appears inside. In such situations, the user is faced with a difficult choice: call a technician or try to fix the fault on his own, which is associated with serious risks and requires specific skills.
Replacement motor-compressor is a complex technical process that requires not only physical effort, but also a deep understanding of the operating principles. refrigeration circuit. It must be taken into account that high pressure refrigerant circulates inside the system, and special tools and materials are required to seal the connections. Errors at the dismantling or installation stage can lead to repeated breakdown, freon leakage or even fire of the electrical wiring.
Before taking active steps, you should soberly assess your capabilities and the availability of the necessary equipment. If you do not have experience working with with blowtorches vacuum pumps, it is better not to risk it and contact a specialized service. However, for those who are determined to carry out do-it-yourself repairdetailed instructions are presented below, describing all the stages of replacing the unit.
Diagnostics of the fault and signs of breakdown
The first step in any repair is accurate diagnostics. The lack of cold does not always indicate the failure of the compressor. Often the problem lies in the thermostat, start relay, or refrigerant leakage through microcracks in the evaporator tubes. It is necessary to listen carefully to the operation of the unit: if the motor hums but does not start, or turns on for a few seconds and immediately clicks, this is a sure sign of a problem in the electrical part or mechanical jamming.
Visual inspection can also give important clues. Pay attention to the condition start relay: if it turns black or emits a burning smell, perhaps this is the problem, and the compressor itself is working. It is also worth checking the integrity of the windings using a multimeter, testing the contacts for a short circuit or break. If the resistance of the windings is within normal limits, but the engine does not work, there is a high probability of mechanical failure of the internal components.
⚠️ Attention: If the compressor runs continuously without turning off, but there is no cold, this may indicate a freon leak or a blockage in the capillary tube, and not a breakdown of the motor itself. Replacing a working unit in this case will not solve the problem.
To more accurately determine the cause, sometimes it is necessary to check the outlet pressure. However, it is difficult to do this without a pressure gauge station. If you observe that the condenser (grill at the back) remains cold while the engine is running, this is almost guaranteed to indicate a lack of coolant circulation. In such a situation replacement of the compressor is the most likely scenario for restoring the functionality of the equipment.
Necessary tools and materials
High-quality repairs are impossible without the appropriate equipment. A basic DIY kit will not work here, since working with the refrigeration circuit requires creating a vacuum and sealing copper tubes. You will definitely need a gas torch with a cylinder, copper solder and flux. The use of tin or soft solders is strictly prohibited, as they will not withstand pressure and vibration.
To work with refrigerant you will need vacuum pump a filling station with pressure gauges. It is impossible to simply replace the motor without vacuuming the system: the moisture and air remaining inside will lead to the formation of ice plugs and rapid failure of the new compressor. You also need a tool for cutting copper pipes - a pipe cutter, a rimmer and a rolling machine if you plan to make connections using rolling, although soldering is more often used.
Don’t forget to prepare personal protective equipment. Soldering copper tubing involves high temperatures, so heat-resistant gloves and safety glasses are required. In addition, working with refrigerants requires good ventilation of the room, since some types of freons can release toxic substances when in contact with an open flame.
Preparing the refrigerator for repair
Before starting any work, the unit must be completely de-energized. Unplug the power cord from the outlet and gain access to the back wall. It is advisable to move the refrigerator to the middle of the room so that you can move freely around it. All products from the chambers must be removed and the device must be defrosted if there is any ice left in it.
Remove the protective cover covering the compressor compartment. It is usually secured with latches or several screws. Before touching any metal parts, discharge static electricity by touching a grounded object. This is important for the safety of electronics if your model has a complex control unit.
☑️ Preparing to replace the compressor
Inspect the installation site motor-compressor. Dust and dirt often accumulate around it, which can interfere with work. Carefully clean the area around the tubes and electrical contacts. Make sure you have enough room to maneuver the burner and other tools.
Dismantling the old compressor
The dismantling process begins with disconnecting the electrical contacts. Take a photo of the connection diagram or sketch the location of the wires so that when assembling a new device you do not confuse the phase, neutral and ground. Carefully remove the starting and protective relay from the compressor contacts. If they are stuck, do not use brute force to avoid damaging the plastic elements.
The next step is working with copper tubes. They need to be cut with pliers or cut with a special tool, leaving small “stumps” on the compressor. Under no circumstances try to unsolder the tubes without releasing the freon. Although in domestic conditions freon is often simply released into the atmosphere (which is not environmentally correct), this must be done in a well-ventilated area!
in the room being vented. After releasing the pressure, you can begin desoldering.
Using a gas burner, heat the soldering joints of the suction and discharge tubes. When the solder has melted, carefully move the tubes to the sides. Be careful, oil residue may come out of the pipes. It is also necessary to unsolder or bite off the capillary tube if it is soldered directly into the compressor housing, although most often it is connected to a filter drier.
⚠️ Attention: When heating copper tubes, try not to overheat the compressor housing itself and nearby plastic wiring elements. Use a damp cloth to cool nearby areas if the heat becomes too intense.
Once all utilities are disconnected, remove the mounting bolts holding the compressor to the frame. Often rubber shock absorbers are installed between the motor legs and the frame. They need to be saved and moved to a new unit, as they dampen vibration and noise during operation. Remove the old compressor from the frame and dispose of it in accordance with the rules for handling electronic scrap.
Installation and soldering of a new unit
Installation of a new one compressor begins with the preparation of its process pipes. Remove the shipping caps only at the last moment to prevent moisture from getting inside. Place the new motor on the frame, install the shock absorbers and bolt it in place. Make sure that it is level and does not touch the walls of the compartment or other tubes.
Now you need to connect the copper tubes. For this purpose, the hard soldering method is used. Clean the ends of the compressor tubes and pipes to a shine using a rimmer or fine sandpaper. Apply flux and heat the joint with a torch until it turns dark cherry, then apply solder. It should flow into the gap under the influence of the drip effect, forming a sealed seam.
How to solder copper tubes correctly?
For high-quality soldering, the burner flame must cover the joint evenly. Don't hold the flame at one point for too long to avoid burning the copper. Solder should melt from the heat of the metal, not from direct contact with fire. The seam should be smooth and shiny, without holes or sagging.
An important element of the system is the filter drier. Every time the circuit depressurizes, it must be replaced with a new one, since the old one is already saturated with moisture and will not be able to perform its function. Solder the new filter into the gap of the capillary tube, observing the flow direction indicated by the arrow on the body.
After soldering all connections, the system must be purged with nitrogen. This will remove copper oxides formed inside the tubes during heating and check the circuit for major leaks. If there is no nitrogen, this stage is sometimes skipped in makeshift conditions, which reduces the reliability of the repair, but professionals do it without fail.
Evacuating and charging with refrigerant
The most critical stage is creating a vacuum. Connect the vacuum pump to the service connection (usually it is located on the compressor or soldered into the system by you). Turn on the pump and leave it running for at least 30-40 minutes. This is necessary to remove moisture and air, which, during operation of the refrigerator, would turn into ice and acid, which would destroy motor from the inside.
After evacuation, close the pump valve and only then turn it off so that oil does not rush into the system. Now you can start refueling. The weight of the refrigerant is strictly regulated by the manufacturer and is indicated on a tag on the back of the refrigerator. You cannot refill “by eye”: a lack of freon will lead to poor cooling, and an excess will lead to increased pressure and load on the compressor.
| Refrigerant type | Features | Precautionary measures |
|---|---|---|
| R134a | The most common in modern models | Non-toxic, but displaces oxygen |
| R600a | Isobutane, used in new refrigerators | Explosive, requires special care when soldering |
| R12 | Outdated freon, found in old equipment | Toxic, prohibited for production, requires disposal |
Use scales for refilling. Turn the freon cylinder upside down (if you are filling it with the liquid phase through a capillary) or leave it upright (if you are filling it with the gas phase, which takes longer). Monitor the weight of the exhaust gas. After refueling, seal the service pipe, first making sure that the pressure in the system is stable.
Checking the system's performance
After completing all manipulations, connect the refrigerator to the network. Let it run for 15-20 minutes. At this time, listen for sounds: there should be no hissing (a sign of a leak) or loud knocking. The compressor should operate smoothly, with periodic pauses, if the thermostat is working properly.
Check the heating of the condenser (grid at the back). It should be hot at the top and warm or at room temperature at the bottom. This indicates proper refrigerant circulation. Also check the temperature in the chambers: after 30-40 minutes it should become noticeably cooler there.
⚠️ Attention: Technical specifications and refueling requirements may vary depending on the specific model and year of manufacture of the refrigerator. Always check the manufacturer's technical documentation before starting work.
Be sure to check the solder joints for leaks. To do this, you can use a soap solution: apply it to the seams and see if bubbles appear. If there are no bubbles and the refrigerator begins to freeze, the repair can be considered successful.
Replace the protective cover of the compressor compartment, but do not screw it tightly yet. Observe the operation of the unit for several hours. If all parameters are normal, you can complete the assembly and load the products.
Common mistakes when replacing
One of the most common mistakes is neglecting to replace the filter-drier. Many people believe that if it “looks normal” then there is no need to change it. However, inside it there is zeolite, which upon contact with air instantly loses its properties. Installing an old filter will negate all vacuuming efforts.
Poor soldering quality is also common. Insufficient heating leads to the fact that the solder does not flow into the gap, forming a “dead” solder that flows under pressure. Overheating can lead to the formation of oxides inside the tube, which subsequently clog the capillary. Balance and experience are required.
Some technicians forget to check the insulation resistance of a new compressor. If the winding “pierces” the housing, such a motor will not work and can be life-threatening. Always check with a multimeter that there is no contact between the leads and the copper body of the compressor before installation.
What to do if the compressor does not start after replacement?
First of all, check the voltage in the network and the integrity of the starting relay. If the relay is working properly, it is possible that oil has entered the system and clogged the capillary, or a water hammer has occurred. In rare cases, a new compressor may be defective.
Ignoring safety rules when working with R600a refrigerants can lead to an explosion. This gas is heavier than air and accumulates at low points. Before soldering near such systems, it is necessary to thoroughly ventilate the room. You should not risk your life to save on calling a specialist.
Questions and answers (FAQ)
How long does it take to replace a compressor at home?
For an experienced technician with a full set of tools, the process takes about 2-3 hours. For a beginner doing this for the first time, the time can stretch to 5-6 hours or more, especially if difficulties arise with soldering or troubleshooting.
Is it possible to replace a compressor without soldering the tubes?
There are quick-release coupling systems (lock rings), but they are considered less reliable than soldering and are not recommended for long-term operation. In addition, they are not suitable for all models and pipe diameters.
Is it necessary to flush the system after the compressor burns out?
Yes, if the compressor burns out, acidic oil and combustion products enter the system. Simply replacing the motor without flushing the circuit with nitrogen and special liquids will lead to rapid failure of the new unit. In such cases, a complete overhaul of the system is often required.
Where can I get an exact analogue of the compressor for my model?
Look for the markings on the nameplate of the old compressor. Not only the overall dimensions are important, but also the cooling capacity, type of refrigerant and power. It is best to look for the original or proven analogues from brands like Danfoss, Secop or Embraco.