Motor, or, in technical terms In short, the compressor is the heart of any modern refrigeration equipment. It is this unit that is responsible for creating the pressure necessary to circulate the refrigerant through the pipe system. Without proper operation of this mechanism, the cooling process becomes physically impossible, since freon will not be able to effectively transfer heat to the environment.
Understanding the principles of operation of this unit allows owners of household appliances to better understand the causes of breakdowns and not trust repairs to unqualified craftsmen. In this article, we will analyze the internal structure in detail, consider the differences between different types of engines and learn to recognize the first symptoms of an impending breakdown.
Service center statistics show that problems with the compressor make up a significant proportion of all repair calls. Often an expensive replacement is caused by simple neglect of operating rules or untimely cleaning of the heat exchanger. Let's figure out how to protect equipment from premature failure.
Main purpose and operating principle
The main task of the motor is to compress the gaseous refrigerant and forcefully pump it through a closed circuit. During operation, there is a constant change in the pressure and temperature of freon, which allows heat to be removed from the refrigerator chambers. This physical process underlies the operation of all household freezers.
When compressor turned on, it sucks refrigerant vapor from the evaporator, where it has warmed up, taking heat away from the food. Then a sharp compression of the gas occurs, causing its temperature to rise significantly. Under high pressure, the hot gas enters the condenser, usually located at the rear of the unit, where it cools and turns into liquid.
Next, the liquid refrigerant passes through a capillary tube and a throttle valve, where the pressure drops sharply. Once in the evaporator, the liquid boils at a very low temperature, turning back into steam and starting the cycle all over again. This continuous circulation ensures stable cold inside the chambers.
⚠️ Attention: The motor-compressor operates under high pressure. An independent attempt to open a sealed casing or re-solder tubes without special equipment can lead to an explosive situation or the release of toxic gas.
The effectiveness of the entire system directly depends on the tightness of the circuit and the performance of the injection unit. If a microcrack appears in the system, the pressure drops and the motor begins to wear out, trying to compensate for the leak. That is why tightness is a critical parameter of durability.
Design features of the electric motor
A complex mechanism consisting of an electric motor and the compressor part itself is hidden inside the metal casing. The engine shaft is rigidly connected to the piston or rotor group, which compresses the gas. This entire structure is suspended on springs inside the housing to dampen vibrations.
To lubricate the rubbing parts, a special compressor oil is used, which is located in the lower part of the casing. When starting up, oil splashes and gets into the gaps between moving parts, reducing friction and dissipating heat. The quality and level lubricant directly affect the service life of the unit.
Modern models are often equipped with additional protection elements, such as a thermal relay and a start-protective device. They control the temperature of the windings and the current, turning off the power in case of overload. This prevents the windings from burning out and the expensive unit from failing.
Why is the motor hot?
During operation, the compressor housing can heat up to 80-90 degrees Celsius. This is a normal phenomenon, as gas compression and friction of parts occurs inside. However, if the temperature exceeds 100 degrees or a burning smell is heard, this is a sign of a malfunction of the cooling system or a freon leak.
It is important to note that the electric motor operates in an aggressive environment saturated with oil and refrigerant vapors. The winding insulation must withstand high temperatures and chemical exposure. Violation of the insulation leads to an interturn short circuit, which often requires a complete replacement of the unit.
Types of compressors in refrigerators
There are several types of motors on the household appliances market, each of which has its own advantages and disadvantages. The choice of a specific design affects energy consumption, noise levels and the cost of repairs in the future.
The most common are piston models, where compression occurs due to the reciprocating movement of the piston. They are reliable and repairable, but create noticeable vibration. In recent years, motors that operate smoothly and without constant switching on and off have been gaining popularity. inverter engines that run smoothly and without constant switching on and off.
⚠️ Attention: Inverter compressors are extremely sensitive to voltage drops in the electrical network. To protect them, it is strongly recommended to use a voltage stabilizer, especially in houses with old wiring.
There are also rotary and screw compressors, which are more often found in industrial installations or premium models of refrigerators. They are characterized by high performance and compact dimensions, but their repair requires unique spare parts and highly qualified technicians.
Below is a comparative table of the main types of compressors used in household appliances:
| Compressor type | Noise level | Energy efficiency | Operating life |
|---|---|---|---|
| Piston (regular) | Medium/High | Standard | 7-10 years |
| Inverter | Low | High (class A++) | 10-15 years |
| Linear | Low | Very high | 10+ years |
| Rotary | Medium | High | 8-12 years |
When choosing a new refrigerator, you should pay attention not only to the brand, but also to the type of installed engine. Inverter models can save up to 40% of electricity compared to classic analogues, which in the long run pays off their higher initial cost.
Typical malfunctions and their symptoms
Diagnostics of the condition of the motor is often possible without opening the casing, simply by external signs and sounds. If the refrigerator has stopped freezing, but the light in the chamber is on, this is the first signal of problems with the compressor group or its start circuit.
One of the common problems is the failure of the start relay. In this case, the engine hums, trying to start, but after a few seconds there is a click and it goes silent. Repeated startup attempts occur cyclically until the thermal protection is triggered.
Another common malfunction is turn-to-turn short circuit windings. In this case, the engine may hum quieter than usual or, conversely, work with overload, becoming very hot. Often this knocks out the circuit breakers in the apartment's electrical panel.
- 🔊 Knock and clang: Indicates mechanical wear of piston group or suspension springs.
- 🌡️ Overheating of the housing: The casing cannot be held by hand for more than 2-3 seconds.
- ❄️ Lack of cold: The compressor works constantly, but the temperature in the chambers does not drop.
- 💡 Flashing light: When the engine starts, the light in the refrigerator or apartment may dim due to a current surge.
If you notice that the motor has been running continuously for days, this may indicate a freon leak or a leak in the circuit. In this case, the engine tries to compensate for the lack of cold by working at the limit of its capabilities, which quickly leads to its combustion.
Diagnostics and performance testing
To accurately determine the cause of the malfunction, technicians use a multimeter and a pressure gauge station. The initial check begins with measuring the resistance of the motor windings. Normal resistance values depend on the model, but usually amount to several tens of ohms for the starting and operating windings.
If the multimeter shows infinity, it means there is an open circuit. If the resistance is close to zero, a short circuit has occurred. It is also important to check the resistance between the windings and the body (for “breakdown”), which should be infinitely large.
⚠️ Attention: Before taking any measurements, be sure to disconnect the refrigerator from the power supply! Working with live electrical circuits is deadly.
The second diagnostic stage is checking the discharge pressure. A pressure gauge is connected to the compressor outlet. A working motor should create a pressure of at least 6 atmospheres (bar) per minute of operation. If the pressure is significantly lower, there may be problems with the valves or piston group.
☑️ Primary diagnostics of the motor
Visual inspection can also provide a lot of information. The presence of oil stains around the pipes or under the refrigerator indicates a leak. Blackening of the filter drier may indicate moisture entering the system or oil combustion products.
Repair or replacement: which is more profitable?
The question of the feasibility of repairs often arises before owners of equipment more than 5-7 years old. If the compressor itself fails (the mechanics are jammed or the windings are burned out), then in 95% of cases it requires a complete replacement. Restoring a sealed unit at home is impossible.
The cost of a new compressor, including the work of a technician and refilling with freon, can be up to 60-70% of the price of a new refrigerator. In such cases, it is economically justified to purchase new equipment that will have a guarantee and a modern energy efficiency class.
However, if the problem lies in the start relay, thermostat or freon leak, repairs are completely justified. These components are inexpensive, and replacing them extends the life of the main unit for many years.
When making a decision, it is also worth considering the condition of the thermal insulation and housing. If rust has eaten through the walls or the insulation is damaged, even a new motor will not ensure high-quality operation of the refrigerator. In this case, replacing the entire unit is the only reasonable solution.
Prevention and extension of service life
In order for the refrigerator motor to serve as long as possible, you must follow simple operating rules. First of all, this is to ensure adequate ventilation. The rear wall of the unit must be at least 10 cm from the wall so that the heat from the condenser can be freely dissipated.
Regular defrosting (for models with manual defrosting) prevents the formation of an ice coat, which impairs heat transfer and makes the compressor work longer. The presence of a thick layer of ice on the evaporator is a direct road to overloading the engine.
- 🧹 Cleaning the condenser: Once every six months, vacuum the grill at the back of the refrigerator to remove dust and hair.
- 🚫 Prohibition of hot things: Never put hot food in the chamber, this sharply increases the load on the motor.
- ⚖️ Level installation: Use a level to install the refrigerator to avoid distortion and vibration of the motor.
It is also important to monitor the integrity of the door seals. If the rubber does not fit tightly, warm air enters the chamber and the compressor is forced to work almost non-stop. The seal can be checked using a sheet of paper: hold it with the door and try to pull it out - it should come out with force.
Following these simple recommendations will avoid sudden breakdowns and costly repairs. Remember that prevention is always cheaper than restoring or buying new equipment.
Is it possible to replace a conventional compressor with an inverter one?
Theoretically it is possible, but it is technically very difficult and economically impractical. Inverter motors require a special electronic control unit, which is not found in conventional refrigerators. It will be necessary to completely redo the electrical circuit, which will entail high costs and loss of warranty.
Why does the refrigerator motor vibrate strongly?
Vibration can be caused by loose compressor mounting bolts, burst shock-absorbing springs inside the casing, or contact of the tubes with the body of the refrigerator. Sometimes vibration is transmitted from the floor if the refrigerator is not level.
How much does it cost on average to replace a motor?
The cost consists of the price of the unit itself (from 3,000 to 15,000 rubles depending on the model), the cost of the work of a technician, new freon and filter. On average, replacement costs from 6,000 to 12,000 rubles, but prices may vary depending on the region and brand of equipment.