Sudden silence in the kitchen or, conversely, the booming sound of a running unit without cooling often indicates problems with compressor. This is the heart of your refrigerator and is what creates the pressure needed to circulate the refrigerant. When the motor stops starting or works intermittently, the owner is faced with the question: can the device be repaired on its own or is a complete replacement of the unit required? The answer lies in competent diagnostics and careful access to internal components.
Before proceeding with disassembly, it is important to understand that hermetic compressor is not intended for opening at home without special equipment. However, by “opening the engine,” craftsmen more often mean dismantling the unit from the niche, removing the protective casing and checking the starting equipment. It is these actions that make it possible to identify 90% of faults, such as a burnt-out starting relay or winding. In this article we will analyze in detail the process of safe engine removal and initial diagnostics.
It is worth noting that modern models, be it Indesit, Atlant or Liebherr, have a similar engine compartment layout. However, the design of the start-up relay may differ. Your task is not to damage the copper tubes and electrical contacts during dismantling. Incorrect actions can lead to freon leakage or electric shock, so following safety precautions is the number one priority.
Required Tools and Safety Precautions
Working with electrical equipment and potentially hazardous gases requires training. You will need a basic set of tools that most DIYers will have in their garage. Pay special attention to insulating tools and protecting your hands, since there may be sharp metal edges inside the casing.
- 🔧 A set of screwdrivers (phillips and flat) for removing fasteners and clamps.
- 🔨 Pliers or pliers for working with clamps and wires.
- 🧤 Dielectric gloves for protection against residual voltage.
- 🔦 Flashlight for illuminating a darkened engine compartment.
- 🧼 Solvent or alcohol to clean contacts from oxides.
The first step should always be to completely disconnect the device from electrical networks. It is not enough to simply turn off the button; you must remove the plug from the socket. Capacitors in the circuit can retain a charge, so it is recommended to wait 10-15 minutes before touching any metal parts of the compressor. This is a standard procedure for any equipment with electric motors.
⚠️ Attention: It is strictly forbidden to cut through or bend the copper tubes coming out of the compressor. There is freon under pressure inside the system. Damage to the circuit will lead to an immediate release of gas and will require an expensive professional refill of the system.
If you plan not just to remove the casing, but to take measurements with a multimeter, make sure that the device is working properly and is set to resistance measurement mode. Access to the bottom of the refrigerator may require the assistance of a second person to safely tilt the unit without damaging the floor or doors.
Compressor Access: Removing the Guard
The compressor in most refrigerators is located at the lower rear of the cabinet. To get to it, the unit must be moved away from the wall and access must be provided from all sides. In some models, for example, old ZIL or Biryusa, access may be limited by the design of the rear wall.
The process of removing the protective box (casing) usually does not cause difficulties. It is secured with latches or screws. Carefully bend the tabs of the latches or unscrew the fasteners. By removing the metal or plastic cover, you will see the motor-compressor itself, the condenser (often in the form of a grille at the back) and the start relay.
☑️ Check before dismantling
Inspect the area around the motor. There should be no traces of oil or burning. If you notice black smudges, this may indicate a breakdown of the gaskets or burnt out windings. Visual inspection helps save time for further diagnosis. Sometimes the problem is immediately obvious: a torn wire or a clearly swollen capacitor.
Removing the start relay and electrical parts
The most common cause of refrigerator failure is a malfunction of the start relay. This small plastic block attaches to the side of the compressor. It is he who provides the impulse to start the engine. To remove it, you need to carefully disconnect the terminals and remove the lock.
Proceed with caution: the wires may become dry over time and break easily. If the insulation is cracked, it is better to immediately replace the terminals or use heat shrink during assembly. The relay is removed by moving downwards or to the side, depending on the model (Danfoss, Secop or domestic analogues).
- 📸 Take a photo of the wire connection diagram before removal so as not to confuse them during assembly.
- 🧹 Clean the contacts of the relay and compressor from oxides alcohol.
- 🔍 Check the relay for cracks or a burning smell.
- 🔌 Carefully disconnect the connectors without pulling the wires themselves.
After removing the relay, you will have access to the winding contacts on the compressor body. It is important here not to lose the rubber gasket-seal, if it is structurally provided for in your model. Its loss may lead to moisture entering the contacts in the future.
Removing the compressor from the refrigerator frame
If diagnostics showed that the motor itself is faulty, or if you need to replace it entirely, you need to remove the unit from the frame. The compressor is mounted on four shock absorbers or bolts. Modern models often use spring-loaded studs with rubber bushings.
First, you need to bleed off the refrigerant if you do not plan to maintain the tightness of the system (which is impossible to do at home without equipment). However, if you are replacing a compressor, the technician will first resolder the tubes. Within the framework of the article, we are considering dismantling to replace the entire assembly.
| Type of fastening | Tool | Features of dismantling |
|---|---|---|
| Threaded rods | Key 8-10 mm | Requires access from below, the nuts can sour |
| Spring shock absorbers | Pliers | You need to compress the spring and remove it from the support |
| Welded brackets | Glinder/Hacksaw | Dismantling only with damage to the frame (rarely) |
When disconnecting the compressor, support it with your hand. It is quite heavy (about 10 kg), and a fall could damage the floor or the unit itself. Also make sure there is no strain on the copper tubes. If they are soldered, they must be cut with pipe cutters, after making sure that the pressure in the system has been released.
⚠️ Attention: When cutting the tubes, a hissing of escaping gas may be heard. Work in a well-ventilated area. Freon is lighter than air, but its concentration in a confined space is undesirable. Avoid open fire near the work site.
Diagnostics of windings and integrity check
After removing the engine, the inspection stage begins. You will need a multimeter. There are three contacts on the compressor housing (usually labeled C, S, R or just dots). It is necessary to “ring” the windings for an open or short circuit.
The normal resistance of the starting winding is usually higher than that of the working winding. If the device shows infinity, the winding has burned out (break). If the resistance is close to zero, an interturn short circuit has occurred. In both cases, repairing the compressor at home is impossible; replacement is required.
Table of typical resistances
The resistance between the contacts depends on the power of the motor. For small refrigerators (100-150 W), the resistance of the working winding is 10-25 Ohms, the starting winding is 30-50 Ohms. A significant downward deviation indicates a short circuit.
Also check the resistance between any contact and the copper tube (housing). The device should show infinity. If there is at least some value, it means that the insulation is broken and the motor “breaks through” the housing. Operating such a refrigerator is deadly.
Installing a new engine and testing
Replacing a compressor is a complex process that requires soldering copper tubes and evacuating the system. If you replaced only the relay, installation is performed in the reverse order. Make sure that the new relay matches the markings of the old one or the manufacturer's recommendations.
When installing a new compressor, the technician fills the system with freon and oil. It is impossible to do this on your own without scales and a vacuum pump. Therefore, if you have dismantled the motor itself, it is better to entrust further actions to professionals, providing them with an already prepared unit.
- 🔩 Securely fasten the compressor to the shock absorbers to avoid vibration.
- 🔌 Connect the wires according to the photograph or diagram taken earlier.
- 🧪 Check that all electrical connections are securely fastened.
- 🔊 After turning on, listen to the operation: there should be no knocking or buzzing.
After assembly, turn on the refrigerator. For the first few minutes, it may be noisier than usual - this is oil escaping into the system if the compressor has been replaced. If only the relay was changed, the unit should start immediately and after 10-15 minutes begin to cool the chamber.
Frequent errors during disassembly and assembly
Beginners often make mistakes that lead to repeated breakdowns. The most common is the loss or incorrect installation of damper rubber bands. Without them, the vibration of the compressor will be transmitted to the housing and tubes, which will lead to their breakdown in a short time.
Another mistake is ignoring the condition of the wires. You cannot twist them with electrical tape, only soldering or using high-quality terminals. Poor contact will cause heating, melting of the insulation and possible fire.
⚠️ Warning: Never run the compressor without a capacitor connected or with a faulty relay for more than 5-10 seconds. This can lead to burning of the windings and final failure of the unit.
Carefully monitor the position of the compressor during transportation and installation. It can only be tilted at a certain angle (usually no more than 40 degrees) and only in a certain direction so that oil does not enter the refrigerant circuit.
Questions and answers (FAQ)
Is it possible to repair a hermetic compressor yourself?
No, it is hermetically sealed The compressor is sealed at the factory. To open it, you need to cut off the metal, replace the internal parts (valves, piston) and weld the body again to ensure tightness. It is impossible to do this at home; it is easier and cheaper to replace the entire assembly.
Why does the compressor hum but does not start?
Most likely, the piston is jammed in the cylinder or the starting relay has failed. It is also possible that the cause is low voltage in the network or a faulty capacitor. First, check the relay - this is the cheapest and most common reason.
How long does a compressor last in a refrigerator?
The average service life of a modern compressor is 10-15 years. However, with frequent power surges, overheating or improper operation (for example, installation close to the wall), the period can be reduced to 5-7 years.
Is it necessary to change the oil in the compressor when replacing it?
The new compressor is already filled with the required amount of oil at the factory. It makes no sense to add or change oil in an old compressor, since the cause of the breakdown usually lies in mechanical wear or burnout of the windings, and not in the properties of the oil.