Dismantling and subsequent disassembly refrigeration compressor is a complex technical process that requires not only special tools, but also a deep understanding of the structure of the sealed unit. Most often, this procedure is resorted to when it is necessary to replace the motor, eliminate a serious freon leak, or conduct professional diagnostics of internal valves. It is important to understand that the factory sealing of the case does not imply its opening, therefore any actions on disassembly are irreversible and require subsequent soldering and vacuuming of the system.
Before starting work, you must clearly understand risks associated with high pressure inside the system and the presence of toxic substances in the oil. Improper handling of tubes or failure to follow the sequence of actions can lead to injury or permanent failure of the equipment. In this article we will take a detailed look at how to safely remove the unit from the frame, disconnect the lines and what is inside the metal casing.
⚠️ Attention: Before starting any work on dismantling the compressor, you must completely disconnect the refrigerator from the electrical network. Residual voltage in the starting relay capacitors can be dangerous, so let the equipment stand turned off for at least 15-20 minutes.
Necessary tools and workplace preparation
High-quality preparation of the workplace is half the success when repairing complex household appliances. To dismantle and open the compressor, you will need a set of specialized tools, without which it is almost impossible to do the job safely. The main tool for working with copper tubing is a pipe cutter, which allows you to make a clean cut without creating metal shavings that can clog the system.
It is also critical to have on hand the appropriate size wrenches, insulated pliers and a heavy-duty screwdriver for removing protective covers. If you plan to further diagnose the insides of the motor, you cannot do without a multimeter to check the windings and integrity of the thermal relay.
☑️ Tools for dismantling
Do not forget about personal safety: working with metal parts and possible refrigerant residues requires the use safety glasses and thick gloves. Copper tubes can become oxidized and brittle after prolonged use, so sudden movements may cause splinters or sharp edges to fly away.
Removing the compressor from the refrigerator frame
The process of removing unit from the refrigerator niche begins with access to the rear technical panel. It is usually secured with several self-tapping screws or plastic latches, which require careful handling so as not to break them during dismantling. After removing the panel, access opens to the bottom of the refrigerator, where the compressor is mounted on a special stand or directly on the frame.
The motor is attached to the frame, as a rule, through four rubber shock-absorbing bushings, which dampen vibration during operation. To remove the unit, you must carefully lift it or unscrew the mounting bolts if the design provides for rigid fixation. Be careful: the weight of the compressor can reach 10-15 kg, and it is often covered with a layer of industrial dust and oil.
- 🔧 Unscrew the fastening nuts or bolts holding the compressor feet to the frame.
- 🛑 Carefully remove the unit from the rubber shock absorbers, avoiding sudden jerks for the tubes.
- 🧹 Clean the surface of the motor from dust before starting further manipulations.
At this stage it is important not to damage filling pipe, which often protrudes from the side or back of the case. Accidentally breaking it off will result in the immediate release of residual pressure and will require complex soldering to restore the seal if you plan to use this compressor again.
Disconnecting the electrics and dismantling the attachments
The next critical step is to disconnect the electrical part. At the end of the compressor there is a plastic casing that covers the starting and protective relay, as well as the capacitor. Removing this casing requires care, since the plastic clips become brittle over time from constant heating.
Inside you will see contacts going to the terminals of the motor windings. Before disconnecting them, it is recommended to check again that there is no voltage with a multimeter. Start relay Thermal protector (protective tablet) is easy to remove, but requires careful inspection for melting or carbon deposits, which often indicates the cause of the breakdown.
⚠️ Caution: Never attempt to remove relays or wires by holding the compressor suspended by the electrical contacts. This can lead to a break in the internal terminals of the windings, after which it will be impossible to restore the motor without a complete overhaul.
After removing the electrics, you can dismantle the capacitor if it is mounted separately on the housing or frame. It is better to immediately sort all the removed parts, since when reassembling or installing a new unit, exact compliance with the connection diagram will be required.
Disconnecting copper lines
The most crucial moment before completely insulating the compressor is disconnecting the copper tubes. The suction and discharge lines go directly to the motor housing. To disconnect them, use a pipe cutter, which is installed perpendicular to the tube at a distance of 10-15 cm from the point of entry into the housing.
Rotating the pipe cutter around the axis, you must gradually tighten the cutting roller feed screw. When the tube is cut, it is important to pinch the opened hole with your finger or plug to prevent moisture and air from entering the system if the compressor is planned to be reused.
If you don’t have a pipe cutter at hand, you can use a hacksaw with a fine tooth, but this method is less preferable due to the risk of chips forming. After cutting off the tubes, the compressor is considered a completely autonomous unit, ready for movement or further disassembly of the housing.
Opening the sealed compressor housing
Disassembling itself sealed housing is a procedure that turns the factory unit into a unit open for repair. Factory welding of the two hemispheres of the housing does not allow simply unscrewing the bolts, so opening requires the use of an angle grinder (grinder) with a thin cutting disc.
The cut must be made strictly along the weld seam connecting the upper and lower parts of the housing. Work must be carried out slowly and carefully so as not to damage the internal windings of the stator and rotor, which are located close to the walls of the housing. Sparking during cutting is unacceptable, since there may be oil vapors and residual gas inside.
- 📏 Mark the cut line with a marker, focusing on the factory weld.
- ⚙️ Secure the compressor in a vice or stops to prevent vibration when cutting.
- 🛡️ Use safety glasses and a mask, as metal dust will fly in all directions.
After the seam has been passed around the entire perimeter, the top cover is removed, allowing access to the “insides” of the motor. The stator, rotor, shaft and valve system are now visible. This is where the causes of knocking, jamming or loss of performance often lie.
What's inside the compressor?
Inside there is an asynchronous electric motor immersed in oil. The engine rotor is rigidly connected to the crankshaft, which drives the piston group. This entire structure is suspended on springs inside a metal casing to reduce vibration.
Diagnostics of internal components and valve group
After opening the housing, access to the valve group located at the end of the cylinder opens. This is where breakdowns most often occur, leading to a lack of pressure. Repetal valves (plates) may burst, deform or simply wear out over time, no longer fitting tightly to the seat.
For diagnostics, you need to unscrew the cylinder head and carefully examine the condition of the valves and gaskets. If cracks are visible on the plates or they have lost their elasticity, replacing them can revive the compressor. However, if scuffs are found on the cylinder surface or the piston itself, then repair becomes economically unfeasible.
| Component | Signs of malfunction | Action |
|---|---|---|
| Start valve | No start-up, humming | Replacement of relay |
| Repetal valve | Poor cooling, long operation | Replacement of plates |
| Piston group | Knocking, jamming | Replacing the compressor |
| Stator windings | Short circuit, break | Rewinding or replacement |
It is also worth checking the condition of the plain bearings on the shaft. If the shaft has play or visible damage, this will lead to rapid wear and repeated failure even after replacing the valves. The internal part crankcase must be clean, without oil combustion products or metal shavings.
Assembly and sealing the system
If the diagnosis and replacement of defective parts was successful, the question of assembly arises. Restoring factory tightness by conventional welding at home is extremely difficult and dangerous. Most often, to connect the housing hemispheres, a bolted connection with a rubber gasket or sealant is used, which is a temporary solution.
For full commissioning after disassembly, professional equipment is required: a vacuum pump to remove moisture and air, as well as a refrigerant charging station. Without creating a vacuum, moisture will remain in the system, which, when frozen, will block the capillary tube, and the oil will lose its lubricating properties.
⚠️ Attention: Independent soldering of copper tubes and refilling with freon without the appropriate license and equipment is prohibited by the legislation of many countries due to the environmental hazards of refrigerants. In addition, improper refueling can lead to an explosive concentration of gas.
Therefore, if you have disassembled the compressor for the purpose of repair for subsequent installation back into the refrigerator, be prepared to call a specialist for the final stage: soldering, vacuuming and refueling. Disassembly down to the level of the valves is acceptable for diagnostics, but a complete overhaul of the motor at home rarely gives a durable result.
Is it possible to disassemble a compressor without sawing the housing?
The factory design of hermetic compressors does not provide for disassembly without destroying the weld. There are service compressors with screw plugs, but they are practically never found in household refrigerators. Any attempt to open the housing without a grinder or a hacksaw will only lead to deformation of the metal.
Why may the compressor stop working after disassembly?
If disassembled carelessly, it is easy to damage the thin stator windings, disrupt the balancing of the rotor or damage the internal suspension. In addition, moisture or dust entering the windings before assembly will cause a short circuit. It is also critically important to maintain the factory spring suspension angle.
Is it worth repairing an old compressor or is it easier to buy a new one?
In most cases, buying a new compressor is more economical and reliable. Repairing an old one requires costs for tools, new valves, oil, freon and the work of a vacuum technician. The warranty for a new unit is 1-2 years, while a refurbished one may fail at any time.
What kind of oil should be poured into the compressor after repair?
The type of oil depends on the type of refrigerant. For freon R12 and R134a, mineral or alkylbenzene oils are used (for example, Mobil, Emkarate). For freon R600a (isobutane), polyester oils (POE) are used. Mixing different types of oils is strictly prohibited, as this will lead to the formation of acids and clogging of the system.