Replacement compressor is a complex technical operation that requires not only special skills, but also professional equipment. Many owners of household appliances are wondering whether it is possible to perform this procedure themselves in order to save on the services of service centers. The answer is clear: theoretically this is possible, but in practice, without a vacuum pump and a pressure gauge station, the result will be short-lived.
The main difficulty lies not in the physical replacement of the unit, but in the correct calculation of the quantity refrigerant and complete removal of moisture from the system. Residual moisture or air will lead to blockage of the capillary or failure of the new motor in the first hours of operation. That is why sealing and evacuation are critical stages.
Before proceeding with the dismantling of old equipment, it is necessary to conduct a thorough diagnosis. Often, symptoms indicating a breakdown superchargermay indicate problems with the thermostat or a freon leak. If you are determined to change the unit, make sure that the new unit fully matches the characteristics of the old one, otherwise efficiency cooling will be impaired.
Fault diagnosis and selection of components
The first step is always to accurately determine the reason for the lack of cold. Do not rush to buy a new compressor until you are sure that it is the problem. Motor-compressor It may not start due to a burnt-out start relay or a broken winding. Checking the resistance of the windings with a multimeter is a mandatory procedure before starting work.
When choosing a new part, it is important to consider not only the mounting dimensions, but also the type of refrigerant. Modern models often run on R600awhich is explosive, while older models used R134a or R12. Incorrect selection of oil or freon will lead to rapid wear of rubbing parts and destruction of the system.
⚠️ Attention: The use of a compressor designed for a different type of refrigerant is strictly prohibited. Different types of oils can react chemically, forming acid, which corrodes the windings and clogs the system.
You should also pay attention to the power and performance of the unit. Installing a more powerful motor on a weak evaporator will lead to freezing and a violation of the temperature regime. Performance must strictly correspond to the volume of the refrigerator compartment.
Necessary tools and preparation of the workplace
For high-quality installation of the compressor on the refrigerator, you will need a specialized tool, which is rarely found in everyday life. The main device is vacuum pumpnecessary to create a deep vacuum in the system. Without this stage, it is impossible to guarantee the removal of moisture, which, when mixed with the refrigerant, forms ice plugs.
The second irreplaceable element is the pressure gauge station (manifold). It allows you to control the pressure during evacuation and accurately dose the amount of gas being charged. You will also need a solder torch, a pipe cutter, a roller and a set of wrenches. Conventional tin soldering will not work here; you need silver soldering or hard solder.
Preparation of the workplace involves ensuring good ventilation. Since work may be carried out with refrigerant remaining or refilling, the concentration of gases in a confined space is unacceptable. This is especially true isobutane, which is heavier than air and can accumulate near the floor, creating an explosive mixture.
- 🛠️ Two-stage vacuum pump for deep vacuum
- 📊 Manometric manifold with hoses
- 🔥 Gas burner with a cylinder and solder
- 🔧 Pipe cutter and rolling for copper pipes
- ⚖️ Electronic scales for precise refilling with freon
Removing the old compressor
The process of removing the faulty unit begins with completely disconnecting the refrigerator from the power supply. Then you need to gain access to the rear of the unit by removing the protective cover. Before biting off the pipes, the remaining refrigerant should be released. This must be done carefully by piercing the process pipe or biting off the tube away from an open flame.
Next, the suction and discharge tubes are unsoldered. It is important not to damage the copper tubes of the condenser and evaporator, since their restoration will require additional inserts. An old compressor is usually mounted on four rubber studs that dampen vibration. When removing the nuts, you need to hold the studs so as not to tear the threads from the base. with damper bushings, which dampen vibration. When removing the nuts, you need to hold the studs so as not to strip the threads from the base.
After physically removing the motor, it is necessary to inspect the system. Purging the circuits with nitrogen will remove oil combustion products and possible contaminants. If a black suspension is found inside the system, this is a sign of combustion of the windings, and flushing becomes mandatory. Ignoring this step will result in the new compressor failing in a few days.
☑️ Check before dismantling
Installation of a new compressor and soldering of connections
Installation of a new unit begins with the preparation of connecting pipes. The copper must be cleaned and cut strictly perpendicularly with a pipe cutter. Using a hacksaw for metal is unacceptable, as small chips will get inside the system and cause blockage capillary tube. The ends of the tubes are flared for a tight connection.
When soldering, it is important to observe the temperature regime. The torch flame is directed at the joint, not the solder itself. Flux should be used minimally, carefully removing its residues after cooling. Aggressive fluxes can corrode copper from the inside. Particular attention is paid to soldering the filter-drier, which is changed whenever the system is depressurized.
The compressor is attached to the frame using new rubber bushings. It is impossible to rearrange old dampers that have become stiff from time to time, as this will lead to increased noise and vibration. After installation, you need to check whether the tubes touch each other or the walls of the case to prevent rattling during operation.
⚠️ Attention: The soldering time for one connection should not exceed 5-7 seconds. Prolonged heating leads to the formation of an oxide film inside the tube, which narrows the flow area and disrupts the circulation of the refrigerant.
Evacuation and charging with refrigerant
This is the most critical stage on which the entire refrigerator depends. A pressure gauge station and a vacuum pump are connected to the system. The process of pumping out air should last at least 30-40 minutes. The pressure should drop to values close to technical vacuum. This is the only way to evaporate all the moisture contained in the oil and on the walls of the tubes. resource the entire refrigerator. A pressure gauge station and a vacuum pump are connected to the system. The process of pumping out air should last at least 30-40 minutes. The pressure should drop to values close to technical vacuum. This is the only way to evaporate all the moisture contained in the oil and on the walls of the tubes.
After evacuation, the valve on the manifold is closed and the pump is turned off. The system is left under vacuum for 15-20 minutes to check the tightness. If the pressure gauge needle remains in place, you can start refueling. The amount of refrigerant is determined strictly by the weight indicated on the refrigerator nameplate, with an error of no more than 5 grams.
Refilling is carried out only in the liquid phase (if the type of refrigerant and the position of the cylinder allows it) or through the gas phase with the compressor running, controlling the consumption current. An excess of freon is just as dangerous as its deficiency: it can lead to water hammer and destruction of the valves supercharger.
Why can’t you refill “by eye”?
Refilling without pressure scales is possible only for experienced craftsmen and only at a strictly defined ambient temperature. For R600a, this method is absolutely not suitable due to small filling volumes and high risks. An error of 10 grams can change the condensation pressure so much that the refrigerator will stop freezing or the compressor will work with overload.
Correspondence table of refrigerants and oils
The correct combination of refrigerant and oil is the key to stable operation. Below is some background information on compatibility types. The use of incompatible components will lead to stratification of the mixture and lack of lubrication of rubbing pairs.
| Refrigerant type | Type of required oil | Features | Marking color |
|---|---|---|---|
| R12 | Mineral | Outdated, ozone-depleting | White |
| R134a | Synthetic (POE) | Hygroscopic, afraid of moisture | Blue |
| R600a | Mineral / Alkylbenzene | Explosive, small filling | Red |
| R404a | Synthetic (POE) | High pressure, for freezers | Orange |
Typical errors and ways to eliminate them
One of the most common errors is insufficient vacuuming time. Any moisture remaining in the system freezes in the capillary tube, blocking the flow of refrigerant. This manifests itself as cyclical operation: the refrigerator freezes, then turns off due to overheating or the thermostat tripping, then starts again. There is only one solution - complete refilling with a long vacuum.
The second common problem is compressor overheating. This can be caused either by a lack of freon, or by improper placement of the condenser or lack of clearance between the back wall of the refrigerator and the kitchen wall. Heat transfer must be effective, otherwise the discharge pressure will increase, increasing the load on the motor.
Also, craftsmen often forget to change filter drier. An old filter, saturated with moisture and acids, will not be able to clean a new portion of refrigerant. This leads to gradual acidification of the oil and destruction of the winding insulation. Replacing the filter is a mandatory rule for any intervention in the circuit.
⚠️ Attention: Specifications and safety requirements may vary depending on the model and year of manufacture of the equipment. Always check the manufacturer's official documentation before starting work, especially when working with new environmentally friendly refrigerants.
Frequently asked questions (FAQ)
Is it possible to replace an R134a compressor with an R600a?
No, such a replacement is not possible without a complete re-soldering the system. These refrigerants require different types of oils (synthetic vs. mineral) and different compressors. In addition, R600a is explosive, and the system must be completely sealed, and the electrical part must be intrinsically safe.
How long should the new compressor run after installation?
Once turned on, the new compressor should run continuously until the set temperature is reached (usually 1-2 hours), then turn off at the thermostat signal. If it works constantly and does not turn off, there may be a freon leak or a blockage in the system.
Is it necessary to flush the system if the old compressor burns out?
Yes, flushing with nitrogen or a special solvent is required. When the windings burn out, combustion products and acid enter the system, which will instantly damage the new unit. Also, the filter drier must be changed.
Why does the refrigerator not freeze well after replacing the compressor?
There may be several reasons: underfilling or overfilling of freon, the presence of air in the system (poor evacuation), a clogged capillary or a leak in the circuit. Repeated diagnostics with a pressure gauge station is required.