In the event of a sudden breakdown of household appliances, many owners think about doing their own repairs, wanting to save on the services of service centers. Disassembly refrigerator compressor often is the first step in trying to restore the functionality of the unit, but this process requires extensive technical knowledge and strict adherence to safety precautions. The sealed motor housing hides complex mechanics inside, where each screw and valve plays a critical role in creating pressure.
Before you take up the tools, you need to realize that opening the housing is often an irreversible action. If you plan to simply change the oil or check the valves, make sure you have the equipment to seal and evacuate the system afterward. Otherwise, refrigeration compressor after assembly it may turn out to be leaky, which will lead to a rapid loss of freon and the final failure of the unit.
The purpose of this manual is to describe in detail the process of dismantling internal components for diagnostic purposes or major repairs, which is impossible without opening the casing. We will look at the stages of preparation, removing the cover, inspection of the piston group and assessing the condition of the electrical part. Remember that safety comes first, and working with electrical appliances under voltage is strictly prohibited.
Preparation of the workplace and necessary tools
Quality preparation of the space directly affects the success of the operation and the safety of the master. You will need a sturdy table with good lighting, where you can lay out all the parts in the order in which they were removed. The absence of foreign objects and dust minimizes the risk of debris getting inside the mechanism, which is especially critical for precision friction pairs.
For opening a sealed casing, a standard set of screwdrivers will not be suitable, since the casing is usually welded or fastened with special clamps. The main tool here is angle grinder (grinder) with a thin metal disk or a specialized hacksaw. It is also necessary to have a hammer, pliers, a set of open-end wrenches and, preferably, a pneumatic or electric screwdriver for quick work with fasteners.
⚠️ Attention: Before starting any disassembly work, make sure that the compressor has been disconnected from the power supply for at least 24 hours. A residual charge may remain inside the start relay capacitors, which can cause an unpleasant electric shock.
Be sure to prepare a container to drain the old oil, as it may be corrosive or toxic. Gloves made of thick rubber or nitrile will protect the skin of your hands from contact with technical liquids and sharp metal edges. If you use an angle grinder, eye protection glasses are a must-have item of equipment to prevent sparks and metal shavings from entering.
Safety precautions and dismantling external elements
The first stage is to completely de-energize the device and remove it from the refrigeration chamber if we are talking about a built-in unit, or disconnect it from the mains in the case of stationary repairs. It is necessary to bleed off any remaining refrigerant in a well-ventilated area or outdoors, since freon, when mixed with air during combustion, can form toxic compounds. After this, the the starting relay and capacitor are dismantled, which are attached to the side of the case.
Removing the protective casing often requires care so as not to damage the copper tubes if they have not already been cut off. In some models, for example Atlant compressors or Danfoss, the relay is fixed with plastic latches that are easy to break if handled carelessly. Use a flat-head screwdriver to carefully press out the clamps, having previously photographed the wiring diagram.
If the compressor has already been removed from the system, it is necessary to cut off the sealed ends of the suction and discharge tubes. This is done using a pipe cutter or a hacksaw to avoid the formation of chips inside the pipes. After removing the relay and removing the tubes, you are left with a “naked” motor-compressor, ready to open the main body.
☑️ Primary preparation
Opening the sealed compressor casing
The most crucial and risky moment is the separation of the upper and lower body parts. Factory welding ensures a tight seal, but makes reassembly impossible without special equipment. For disassembly, it is necessary to make a neat cut along the entire perimeter of the weld. The cutting depth should be minimal so as not to damage the internal stator windings and valve plates.
An alternative method, applicable to some models where the cover is held on bends, involves drilling out the attachment points or carefully bending the housing petals. However, 90% of modern household refrigerators use welding. When working with an angle grinder, hold the tool at a right angle and move smoothly, taking short breaks so that the metal does not overheat and deform.
⚠️ Attention: It is strictly forbidden to open the body with a chisel and hammer, causing strong blows around the perimeter. This can lead to displacement of the stator relative to the rotor, after which it will be impossible to restore the balancing.
After the seam has been passed in a circle, the top cover is usually removed with a light hand force. Inside you will see an oil bath in which the electric motor and crank mechanism are immersed. Be prepared for the possibility that residual oil may leak out, so use a rag. Visual inspection of internal components is now available for obvious mechanical damage, carbon deposits or broken wires.
Why can't you just open the cover without cutting?
Modern compressors are manufactured using resistance welding to ensure absolute tightness under high pressure. The absence of threaded connections is due to mass production technology and the need to eliminate any freon leaks for the entire service life of the device.
Diagnostics and disassembly of the piston group
The internal structure of the compressor is a complex mechanism where electrical energy is converted into mechanical movement of the piston. The central element is crank mechanismwhich transmits the rotation of the engine shaft to the translational movement of the piston in the cylinder. To access it, it is often necessary to remove the upper part of the stator or dismantle the shaft itself, which depends on the specific design of the model.
First of all, the condition of the valve group located on the cylinder head is inspected. Thin metal plates (reed valves) are responsible for directing the flow of refrigerant. If they are deformed, cracked or sooted, the compressor will not be able to create the necessary pressure. The gap between the piston and the cylinder is also checked: excessive play indicates that the service life has expired and the parts need to be replaced.
For detailed troubleshooting, it is necessary to unscrew the bolts securing the cylinder head and remove it. Under it there is a gasket, which is strongly recommended to be replaced with a new one during assembly, although sealant is often used in garage repairs. The piston is removed together with the connecting rod, allowing you to inspect the plain bearings and the connecting rod pin itself for scoring and play.
Analysis of the electrical part and windings
The compressor electric motor consists of a stator with windings and a rotor mounted on a shaft. A visual inspection of the windings reveals obvious signs of overheating: blackening of the varnish, melting of the insulation, or a characteristic burning smell. If the windings look intact, it is recommended to test them with a multimeter to check the resistance. Normal values vary depending on the power of the motor, but a break or short circuit will be visible immediately.
Particular attention should be paid to the places where the wires exit the housing, where they are sealed in special glass insulators. A leak in this area is a common cause of leaks and moisture getting inside. In some cases, for example, in compressors Aspera or Secop, these contacts can be carefully re-soldered, but high qualifications are required.
The rotor must rotate freely inside the stator without beating or jamming. If the rotor is jammed, an attempt to wedge it manually can only be successful in the early stages of the breakdown. However, if traces of friction (“scoring”) are visible on the surface of the rotor or stator, such a unit cannot be repaired and requires complete replacement.
| Check parameter | Normal condition | Signs of malfunction | Action |
|---|---|---|---|
| Winding resistance | From 10 to 40 Ohms (depending on the model) | Infinity (break) or zero (short circuit) | Replacing the compressor |
| Valve plates | Smooth, even, without cracks | Deformation, carbon deposits, cracks | Replacing plates or heads |
| Gap in bearings | Minimal, no backlash | Knock, free movement of the shaft | Replacement of bushings or assembly |
| Wire insulation | Intact, without chips | Cracks, melting, burning | Insulation restoration |
Assembly, sealing and testing
The assembly process is a mirror image of disassembly, but with the addition of critical sealing operations. After replacing defective parts and thoroughly washing the internal parts with a special solvent, all components are reassembled. Particular attention is paid to cleanliness: one grain of sand that gets into the cylinder can destroy a new compressor in a few minutes of operation.
To restore the tightness of the housing, it is necessary to use specialized welding or, in rare cases, high-quality heat-resistant sealant, followed by tightening the housing halves with bolts (if the design allows). However, the most reliable method remains argon welding, which recreates the factory seam. After welding, a procedure for vacuuming the system to remove moisture and air is required.
The final stage includes filling the compressor with oil (strictly the brand specified in the specification, for example Mineral Oil or POE) and a test run. The motor should run quietly, without vibrations or knocks. The outlet pressure is checked with a pressure gauge and must correspond to the passport data for the given model of the refrigeration unit.
⚠️ Attention: Technical characteristics of oils and sealing requirements may vary depending on the compressor manufacturer. Always check the official documentation or markings on the device nameplate before assembly.
Can I use regular sealant for the lid?
The use of automotive or plumbing sealants is not permitted. They dissolve in refrigeration oil and are destroyed by freon, which will lead to rapid depressurization. Special compounds are required that are resistant to refrigerants and high temperatures.
Is it possible to disassemble a compressor without an angle grinder?
In most cases, no. Factory welding involves the use of a cutting tool. There are rare models with collapsible bolts, but they are practically never found in modern household appliances. Attempts to knock the cover off with a hammer will lead to irreversible damage.
Why does the compressor hum after assembly?
The hum may indicate improper alignment of the rotor, debris getting inside, insufficient oil, or an imbalance of the crank mechanism. Also, the cause may be an incorrect connection of the start relay.
Is it necessary to change the oil during disassembly?
Yes, definitely. Old oil loses its lubricating properties and contains metal wear products and acidic compounds. During disassembly, it is drained, and during reassembly, fresh oil of strictly recommended viscosity and type is poured in.
Are the savings on compressor repair justified?
From an economic point of view, self-reassembly is often cheaper than buying a new unit, but only if you have welding and vacuum skills. If you need to call a technician for sealing and refilling, the cost may be equal to replacing the compressor assembly.