A modern refrigerator is a complex electromechanical device whose heart beats rhythmically and constantly. It is compressor, or in everyday life the “motor”, that is responsible for the circulation of the refrigerant, creating the necessary pressure difference to remove heat from the chamber. Understanding what which engine is installed in your unit helps not only diagnose a breakdown, but also predict the service life of the equipment.
When choosing new equipment or replacing a failed unit, consumers are often faced with incomprehensible abbreviations and marketing terms. Some models make noise and vibrate, while others operate almost silently. The difference lies in the design pump group and the drive.
In this article we will look in detail at what types of compressors exist, how they differ in operating principles and what is best to choose for your kitchen. We will not delve into complex thermodynamic formulas, but will focus on the practical aspects of operation.
The basic principle of operation of the compressor
The fundamental task of any refrigeration engine is to compress the gaseous refrigerant and pump it into the condenser. During the compression process, the gas heats up, releasing heat to the environment, and then, passing through the throttling device, it expands sharply and cools. This cycle is repeated until the temperature inside the chamber reaches the set values.
The key element here is piston group or the spiral mechanism, which directly affects the freon. The movement is transmitted from an electric motor, which, depending on the type of design, can operate in different modes. It is the nature of this movement that determines the noise and durability of the unit.
All modern household refrigerators use hermetic compressors. This means that electric motor and the mechanical part are located in a single welded housing filled with oil and inert gas. This design eliminates freon leakage through the seals, but makes repairing the internal mechanics almost impossible without professional equipment.
⚠️ Attention: Opening the sealed compressor casing at home is strictly prohibited. This requires special tools, evacuation of the system and precise refilling of the refrigerant, otherwise the unit will fail instantly.
Piston compressors: classics of refrigeration technology
The most common type of engine that can be found in the vast majority of refrigerators produced over the last 50 years The principle of their operation is simple: the electric motor rotates the crankshaft, which causes reciprocating motion piston inside the cylinder.
Piston motors are divided into two main subtypes according to the type of drive: crank and connecting rod and crank-link. The former are more common in powerful models, the latter in compact ones. They are reliable and maintainable, although they are inferior to modern analogues in energy efficiency.
The main feature of such engines is cyclical operation. The motor turns on at full power, cools the chamber to the desired temperature and turns off completely. When the temperature rises, the cycle repeats. This creates a characteristic hum when starting and stopping.
- 🔹 High maintainability of the mechanical part if spare parts are available.
- 🔹 Sensitivity to the quality of voltage in the electrical network.
- 🔹 The presence of a starting relay, which often fails first.
- 🔹 Higher level of noise and vibration compared to inverters.
It is worth noting that crank mechanism requires high-quality lubrication. If the refrigerator stood in an inclined position for a long time (for example, during transportation), the oil could drain from the crankcase, which will lead to scuffing of the piston group at the first start.
Linear compressors: the golden mean
The linear motor is an evolution of the piston type, developed primarily by LG, although the technology is used by other brands. There is no crank mechanism here. The piston is driven directly by electromagnetic forces, making translational movements along one axis.
The absence of rotating masses and unnecessary joints significantly reduces the level of vibration and noise. Linear compressor also works on the “start-stop” principle, but does it more smoothly and with fewer friction points. This has a positive effect on the service life of the mechanism.
The energy consumption of such models is lower than that of classic piston analogues, due to reduced mechanical losses. However, they still make clicking noises when turning on and off as they stop completely when the temperature is reached.
| Parameter | Piston | Linear | Inverter |
|---|---|---|---|
| Level noise | High | Average | Low |
| Energy consumption | High | Average | Low |
| Resource | 7-10 years | 10-12 years | 10+ years |
| Price | Low | Medium | High |
It is important to understand that linear technology is not an inverter. It only eliminates unnecessary mechanical motion converters, but the operating mode remains discrete. However, for most users this is an excellent balance between price and quality.
Inverter motors: technologies of the future
The inverter compressor is the pinnacle of the evolution of refrigeration motors at the moment. The main difference is in the control method: the engine does not turn off completely, but only reduces the speed to a minimum, maintaining the temperature in the chamber. A special unit is responsible for controlling the shaft rotation speed - inverter.
Due to the absence of constant starts and stops, wear of mechanical parts is minimized. Peak currents, which usually occur at the moment of start and often cause winding burnout, are absent here. This makes inverter refrigerator extremely reliable and economical.
The operation of such a motor is almost silent. You may only hear a quiet hum when the refrigerator first starts up, or a barely noticeable rustling sound when operating at minimum speed. The temperature regime is maintained with an accuracy of 0.1 degrees, which is ideal for storing food.
Why are inverters expensive?
The high price is due to complex control electronics and the use of rare earth magnets in the motor design, and not just the brand.
However, there is a downside medals. Inverter systems are very sensitive to voltage fluctuations in the network. Current surges can instantly damage the control unit or the motor itself. Therefore, owners of such models it is strongly recommended use voltage stabilizers or surge protectors of a high protection class.
Comparison of characteristics and service life
When choosing between types of engines, it is important to consider not only the price, but also the operating conditions. If your home's electricity fluctuates frequently, an expensive inverter can become a burden. At the same time, the good old piston engine will more easily survive such loads, although it will consume more energy.
The service life of modern compressors, regardless of type, is stated by manufacturers to be around 10 years. In practice piston models they often last 15 years or more, requiring only replacement of the starting relay. Inverters, under ideal conditions, last even longer, but their repairs are much more expensive.
Noise is a critical parameter for studios and small kitchens, where the refrigerator is located next to the dining table. Here, the uncontested leader is inverter models. Linear compressors are also acceptable, but their periodic clicking can be annoying at night.
- 🔸 Piston: noise 40-45 dB, vibration is noticeable.
- 🔸 Linear: noise 35-40 dB, vibration is minimal.
- 🔸 Inverter: noise up to 30 dB, vibration is almost absent.
Symptoms of malfunction and diagnostics
How understand that the refrigerator motor is “dying” or has already failed? The first and most obvious sign is that the refrigerator has stopped freezing, while the compressor itself either does not turn on at all, or works continuously without turning off.
If the motor hums, clicks, but does not start, and after 10-20 seconds there is a click and silence - most likely the problem is starting relay or inter-turn short circuit of the windings. In the case of inverters, an error code is often displayed on the control board, which can be deciphered in the instructions.
Excessive heating of the compressor housing (when it is impossible to touch it with your hand for more than 1 second) also indicates problems. This may be caused by a freon leak when the motor wears out, trying to gain temperature, or by mechanical jamming.
☑️ Motor diagnostics
You should also pay attention to the smell. If there is a smell of burnt wiring or burnt oil coming from the back of the refrigerator, stop using it immediately. This is a sure sign of electrical breakdown or mechanical damage.
⚠️ Attention: Do not attempt to repair the electrical part of the compressor yourself unless you have permission to work with high voltage. Residual voltage in the inverter capacitors can be deadly.
Replacement and maintenance of the engine
Replacing a compressor is a complex technological process that cannot be done “on the knee”. It requires:
1. Taps off the old motor from copper tubes.
2. Installation of a new unit (re-soldering of adapters is often required).
3. Evacuation of the system to remove moisture and air.
4. Precise filling refrigerant of a certain type and weight.
For different models of refrigerators, different types of oils and freons are suitable. Using an unsuitable refrigerant (for example, R600a instead of R134a) may result in an explosion or fire, since isobutane (R600a) is a flammable gas.
Approximate sequence of the wizard's actions:1. Bleed off the remaining freon.
2. Cut/unsolder the tubes.
3. Weld the new compressor (with a solder torch).
4. Connect the vacuum pump for 20-30 minutes.
5. Fill the system using the scales.
6. Solder the process pipe.
Service on the part of the user comes down to basic things: ensuring good ventilation of the rear wall. Dust on the condenser (the black grille at the back) causes the motor to work longer and harder, shortening its life. Regular cleaning of dust with a vacuum cleaner will extend the life of the engine for years.
Is it possible to replace a piston compressor with an inverter one?
Theoretically, yes, but in practice it is economically infeasible and technically difficult. It will be necessary to completely change the control system, select compatible tubes and reprogram the electronics. It’s cheaper to buy a new refrigerator.
Why does a new refrigerator hum loudly for the first 20 minutes?
This is normal. When first started, the system should go into operation, cool a large volume of warm air and freeze the walls of the chambers. After reaching temperature, the inverter motor will slow down and become quiet.
The compressor burned out, is it worth repairing the old refrigerator?
If the refrigerator is more than 10 years old, replacing the compressor is often 60-70% of the cost of new equipment. In such cases, repair is advisable only as a temporary measure or if the model belongs to the premium class.