Faced with a breakdown of household appliances, many owners think about doing their own repairs in order to save on the services of service centers. Disassembling a refrigerator compressor - this is a complex, but often necessary process that allows you to replace a burnt winding, eliminate a jammed piston group, or simply conduct in-depth diagnostics of the unit. However, it is worth understanding that the sealed case hides inside a complex mechanical system operating under high pressure, which requires the utmost care from the master.
Before you begin, you need to realize that a standard household compressor is a soldered unit. This means that it is designed without factory service or reassembly after opening. However, enthusiasts and experienced craftsmen often take this step by carefully cutting off the top cover of the case to gain access to the internals. The success of the operation directly depends on the quality of the tools and strict adherence to safety precautions.
In this article we will consider in detail all stages of dismantling, starting from disconnecting the device from the network and ending with removing internal components. You will learn what tools you will need, how to correctly determine the type of malfunction and whether it is even worth taking on this work yourself. Remember that there is oil inside the compressor, which in no case should get into the refrigerant circulation system during reassembly, otherwise the refrigerator will stop freezing.
Preparation of the workplace and the necessary tools
Quality preparation is half the success of any technical event. To disassemble the motor safely and efficiently, you will need not only free space, but also a specialized set of tools. Not having the right equipment can result in damage to the cabinet or, worse, injury from flying metal shards or sparks.
First of all, make sure that the refrigerator is completely unplugged and defrosted. You should work in a well-ventilated area, since opening the housing may release freon residues or oil vapors. It is also important to prepare a container for draining the technical oil, which is located inside the compressor crankcase.
- 🛠️ An angle grinder (grinder) with a thin cutting disc for metal - the main tool for accurately cutting the weld seam.
- 🔧 A set of screwdrivers and pliers - will be required to dismantle the starting relay and protective casing.
- ⚡ Multimeter —necessary for the initial diagnosis of windings before disassembling.
- 🧤 Safety glasses and gloves —mandatory equipment to protect your eyes from metal shavings and your hands from cuts.
⚠️ Attention: It is strictly forbidden to open the compressor if refrigerant under pressure is still circulating in the system. Preliminary pressure relief should be carried out only by a certified specialist with appropriate equipment for gas recovery.
Pay special attention to the selection of a disk for an angle grinder. A disk that is too thick will leave a wide cut, which will complicate subsequent welding of the body if you plan to weld it back. The thin disc allows you to make the cut as clean and narrow as possible. You should also have a hammer and chisel on hand in case you need to carefully knock off the cover after cutting.
Removing the compressor from the refrigerator body
The process of removing the motor begins with access to the technical area, which is usually located in the lower rear part of the refrigerator. It is important here not to damage the copper tubes of the cooling system, since their restoration will require soldering and evacuating the system. First, remove the protective cardboard or plastic panel covering the compressor compartment.
Before disconnecting the tubes, it is recommended to photograph the connection diagram so that during assembly you do not confuse the discharge and suction lines. Then you need to cut the copper tubes at a distance of 10-15 cm from the compressor housing. This will provide a reserve for subsequent soldering. Electrical wires are disconnected from the terminal box or start relay.
The compressor is secured to the refrigerator frame using four shock-absorbing bushings or bolts. Carefully unscrew the fasteners, supporting the heavy unit with your hand so that it does not fall and damage the floor or its own pipes. After removing the motor, transfer it to a stable workbench for further disassembly.
☑️ Safe dismantling checklist
When working with copper tubes, be careful: even after a long stop, oil under residual pressure may remain in them. Place a rag or container under the cut area. If you plan to completely disassemble the motor, then further steps to cut the tubes on the compressor itself can be performed on the table, providing convenient access from all sides.
Opening the sealed housing: technology and nuances
The most critical stage is breaking the seal of the housing. The factory welding is done very well, so you can’t just open the lid. There are two main methods: mechanical (cutting the rim) and thermal (burning), but the most controlled is the use of an angle grinder.
Secure the compressor in a vice or securely fix it on the floor by stepping on the bottom of the case with your foot through a wooden block. Turn on the grinder and move the disc strictly along the weld seam connecting the upper bowl and the main body. Movements should be smooth, without strong pressure, so as not to damage the internal parts and not bend the edge.
- 👁️ Visual control: constantly monitor the depth of the cut so as not to touch the windings or valves.
- 🔄 Rotation of the body: after passing the circle along the diameter, check whether the cut has passed through.
- 🔨 Separation of parts: if the cut is made well, the top cover should be easily removed after light tapping.
After removing the cover, the internal structure will open in front of you: an electric motor immersed in oil, and crank mechanism. Often this is where the cause of the breakdown becomes visible: broken wires, scuffs on the cylinder or burnt insulation. Inspect carefully the condition of the stator and rotor windings for blackening or mechanical damage.
What to do if there is no grinder?
If you don’t have a grinder, you can use a hacksaw, but it will take much longer. Also, some craftsmen drill holes around the perimeter of the seam, but this method is less accurate and requires subsequent thorough cleaning of the edges from metal shavings.
Diagnostics and disassembly of internal mechanics
After opening the housing, it is necessary to drain the used compressor oil into a prepared container. Its color and smell can tell a lot about the condition of the unit: black color and a burning smell indicate overheating of the windings, and the presence of metal shavings in the oil indicates mechanical wear of the rubbing pairs.
To remove the insides, it is usually necessary to remove the upper pressure plate that holds the stator. It is secured with three or four bolts. After unscrewing them, the electric motor along with the rotor can be removed from the casing. Next comes the disassembly of the crank mechanism: the connecting rod, piston and valve group are removed.
Pay special attention to the valves. These are the thinnest metal plates that ensure one-way movement of the refrigerant. Their deformation or breakage is a common cause of loss of compressor performance. If the plates are intact, but the refrigerator does not freeze, the problem may be a worn-out cylinder or piston.
| Malfunction | External sign | Probable cause | Elimination method |
|---|---|---|---|
| Humming, no start | Warm relay, clicking | Mechanism jammed | Disassembly, cleaning, oil change |
| Poor cooling | Quiet operation, long cycle | Wear of valves | Replacement of valve group |
| Disable protection | Housing heating, knocking out | Interturn short circuit | Rewinding or replacing the motor |
| Knock and vibration | Loud metallic knock | Broken bearing or connecting rod | Replacing the connecting rod and piston group |
If mechanical damage is detected, such as scuffing on the cylinder surface, simply replacing parts may not help, since the geometry of the cylinder is already damaged. In such cases boring cylinder at home is impossible, and the compressor must be disposed of or used as a donor of spare parts.
Replacement of the starting relay and electrical part
Often the problem lies not in the mechanics itself, but in the electrical part, namely in the starting relay. This small block is responsible for starting the engine and turning it off after gaining speed. Before disassembling the motor itself, it makes sense to check and, if necessary, replace the relay, since this is done without opening the pressure housing.
The relay is removed by simply rocking from side to side from the compressor terminals. Inside there may be a posistor (thermistor) or a coil with a moving contact. If the posistor crumbles or the coil burns out, the relay is replaced with a new one. It is important to choose a model with similar characteristics indicated on the marking.
- 🔌 Checking the contacts: make sure that the terminals on the compressor are not oxidized or melted.
- 🌡️ Posistor test: in a cold state it should ring, and when heated, it should break.
- ⚙️ Mechanics: in mechanical relays, check the free movement of the movable core.
⚠️ Attention: When installing a new relay, make sure that it sits tightly and is oriented strictly along the “UP” mark or the upward arrow. An incorrect position can lead to instant burning of the new part or failure to start.
If the diagnostics showed that the motor winding has burned out, then it is almost impossible to rewind it in a home workshop. Special equipment is required for winding the coils and an impregnation varnish that can withstand the effects of freon and oil. In this case, it is more rational to replace the entire compressor unit.
Assembly, welding and performance testing
Assembling a compressor after repair is the reverse process of disassembly, but with the addition of critical sealing steps. If you have changed internal parts, you need to carefully install them in place, lubricate the rubbing surfaces with fresh compressor oil and place the electric motor in the casing.
The most difficult moment is restoring the tightness of the housing. The top cover must be replaced and welded. For this, a welding machine (semiautomatic or argon) is used, since conventional tin soldering will not withstand internal pressure and vibration. The seam must be continuous, without pores or cracks.
After welding, the compressor must be checked for leaks. To do this, nitrogen is pumped into it through a process fitting under a pressure of about 15-20 atmospheres and lowered into a bath of water or the seams are generously lubricated with a soap solution. The appearance of bubbles will indicate the location of the leak, which needs to be welded again.
The final stage is evacuation of the system and filling with oil. The amount of oil must strictly correspond to the specifications of the model (usually from 200 to 400 grams). Excess oil will lead to water hammer, and too little will lead to overheating and jamming. After filling the oil, the technological holes are sealed, and the compressor is ready for installation in the system.
Frequently asked questions (FAQ)
Is it possible to disassemble the compressor without a grinder?
Theoretically, you can try cutting off the seam with a hacksaw or drilling holes around the perimeter, but this is extremely labor-intensive and increases the risk of damage to internal components. The grinder remains the most effective tool for this task.
What kind of oil should be poured into the refrigerator compressor?
The type of oil depends on the type of refrigerant. For freon R12 and R134a, mineral or alkylbenzene oils are used (for example, Mobil, Suniso). For freon R600a (isobutane), polyester oils (POE) are often used, which are hygroscopic and require special care during storage.
Is it worth repairing an old compressor or buying a new one?
Repair makes sense if valves need to be replaced or a small jam needs to be cleared, and you have welding skills. If the winding is burned out or the cylinder is worn out, it is cheaper and more reliable to purchase a new unit, since the service life of the restored unit will be unpredictable.
Why did the refrigerator stop freezing after disassembly?
Most likely, the tightness of the system is broken or the amount of oil is incorrectly selected. It is also possible that moisture or air gets into the system, which requires re-evacuation and refilling with refrigerant by a specialist.