Understanding how exactly the heart of your refrigerator functions helps not only in case of a breakdown, but also when choosing a new one equipment. Compressor is the main unit that creates pressure for the circulation of refrigerant through the system. It is responsible for removing heat from the inner chamber to the outside, providing a low temperature for storing products.
A visual representation of the processes occurring inside the metal casing often provides more information than dry technical descriptions. Video-materials allow you to see the difference in the operation of different types of engines and hear the characteristic sounds of a working and faulty mechanism. Without immersing yourself in theory, it is difficult to distinguish a normal hum from a harbinger of a serious breakdown.
In this article we will analyze in detail the internal structure of the motor, explain the physical principles of its operation and point out critical points that cannot be ignored. Only a sealed housing protects electrical components from freon and oil, ensuring safe operation. Let's start with the fundamentals.
Principle of operation and physics of the process
The fundamental principle of operation is to compress the gaseous refrigerant and force it to move along a closed circuit. Motor-compressor converts electrical energy into mechanical movement, which creates a pressure difference. In the high-pressure zone, the gas condenses into liquid, giving off heat, and in the low-pressure zone it evaporates, taking heat from the chamber.
The process starts when the thermostat detects an increase in temperature and closes the electrical circuit. Start relay supplies current to the stator windings, creating magnetic field that causes the rotor to rotate. This movement is transmitted to the crank mechanism or piston, which begins to pump freon.
It is important to understand that the system is under constant pressure, even when the refrigerator is turned off. That is why any manipulations with tubes require caution and special tools. Violation of the tightness leads to an instant release of refrigerant and moisture entering the system.
⚠️ Attention: Never attempt to open a sealed compressor casing yourself without professional equipment for working with refrigerants. This can lead to injury from flying parts or poisoning by oil and freon vapors.
Internal structure: what's inside the casing
Visually we see only a black metal cylinder with copper tubes and an electrical connector. However, hidden inside this casing is a complex mechanical system operating in an oil bath. The basis is electric motor, which is rigidly connected to the compressor part.
Inside there are:
- ⚙️ Stator and rotor - create torque.
- 🔩 Crank mechanism - converts rotation into translational movement of the piston.
- 🛢️ Valve system - ensures the movement of freon in only one direction.
- 🔊 Noise silencers - special chambers on the suction and discharge tubes.
All these components are mounted on springs or rubber dampers to dampen vibration. Oil, located at the bottom of the casing, is sprayed over the rubbing parts, providing lubrication and heat removal. The absence of oil or its insufficient level leads to rapid wear and jamming.
Access to the insides is possible only by sawing the body, which is an irreversible procedure. Therefore, diagnostics are often carried out by indirect methods: by current consumption, case temperature and background sound.
Types of compressors: differences in design
The household appliances market is dominated by several types of designs, each of which has its own design and operation features. Understanding the difference between them will help you correctly interpret the behavior of your refrigerator.
Comparative table of main characteristics:
| Compressor type | Operating principle | Noise level | Energy efficiency |
|---|---|---|---|
| Piston | Cyclic on/off | Medium/High | Standard |
| Inverter | Smooth change in rotation speed | Low | High |
| Linear | Forward movement of the piston without rotation | Low | Very high |
Piston models are classics and most common in the budget segment. They work jerkily: they turn on at full power, cool the chamber and turn off. Inverter units operate continuously, changing the shaft speed, which allows you to more accurately maintain the temperature and save electricity.
Linear compressors popularized by the LG brand do not have rotating parts in the traditional sense. The piston moves back and forth under the influence of electromagnetic forces. This reduces the number of rubbing parts and increases reliability, but makes the system sensitive to voltage fluctuations.
Why are inverter models more expensive?
Inverter compressors require complex electronics to control the frequency of the current, which increases the cost of production. However, they are quieter and last longer due to the absence of constant starting loads.
Diagnostics of faults by sound and sight
An experienced technician can determine the condition of the unit simply by listening to its operation. Sound diagnostics is the first stage of identifying problems that does not require disassembling the equipment. Humming should be uniform, without sudden changes in tone.
Alarm signals that cannot be ignored:
- 🔨 Metal knocking or clanging - a sign of bearing wear or valve damage.
- 🤐 Silence instead of buzzing - possible winding breakage or jamming of the mechanism.
- 🔥 Strong heating of the housing (more than 90°C) - disruption of oil circulation or interturn short circuit.
- 💧 Oily spots around the unit are a violation of the tightness of the casing or pipes.
If the motor hums but does not start, the problem often lies in the starting relay or capacitor. In this case, a characteristic click is heard and a hum lasts several seconds, followed by silence. Thermal relay at this moment the power is turned off, saving the windings from burning.
To accurately check the starting current and operation of the windings, a multimeter and current clamps are used. The normal operating current must correspond to the model's passport data, which is usually indicated on the tag.
⚠️ Attention: If you smell burning or see sparking in the compressor area, immediately unplug the refrigerator. Further operation may lead to a fire.
☑️ Primary diagnostics of the compressor
Video analysis: on what to watch during analysis
When watching training videos about repairing or installing refrigerators, it is important to pay attention to specific details that often remain behind the scenes. Professional videos demonstrate not just replacement, but an analysis of the condition of internal components.
Key points to observe:
- The condition of the stator windings after removing the casing (no blackening).
- The integrity of the copper tubes and the absence of traces of soldering in the wrong places.
- The quality of the motor mounting inside the casing (no backlash in the springs).
- The color and smell of the oil when drained (should not be black or smell like burning).
On In many videos you can see the process of nitrogen pressure testing, which reveals microcracks. This is a critical stage of repair that cannot be performed at home without equipment. Vacuuming systems before refueling is also a prerequisite for long service.
Pay attention to how the master handles the tubes. They must not be bent or twisted. Any deformation of the copper pipeline narrows the passage hole and creates additional resistance for freon, which overloads the motor.
Safety measures and maintenance
Although the compressor is sealed unit, the surrounding elements require attention. Regularly cleaning the condenser (the black grille at the back or bottom) of dust improves heat transfer and reduces the load on the motor. Overheating is the main enemy of any electrical equipment.
Safe operation rules:
- ❄️ Do not turn on the refrigerator immediately after transportation (let the oil drain for 2-4 hours).
- 🧹 Clean the back wall of dust at least once every six months.
- 🔌 Use a voltage stabilizer if there are surges in the network.
- 🚫 Do not place the refrigerator close to the wall, provide a gap for ventilation.
The service life of a modern compressor is 10-15 years or more. However, if operating conditions are violated, it can fail much earlier. Freoncirculating inside is chemically inert, but upon contact with an open flame it can form toxic compounds.
If you are planning to replace the unit, it is important to choose a model with similar characteristics (power, type refrigerant, oil type). Installing an unsuitable compressor will lead to ineffective operation or rapid breakdown of the new part.
Is it possible to repair the compressor yourself?
Replacing the start relay or capacitor is available to amateurs. However, opening the casing, replacing valves or rewinding the engine requires factory conditions, a vacuum pump and skills in working with non-ferrous metals. It is almost impossible to do this efficiently at home.
Why is the compressor hot, but the refrigerator does not freeze?
This is a classic sign of a freon leak or a clogged capillary tube. The engine idles, trying to pump gas that is not in the system, or overcoming the resistance of a blockage. You need to call a technician to find a leak and refill it.
What is “hydraulic hammer” in a compressor?
This is the entry of liquid freon or oil into the cylinder at the moment of compression. The fluid does not compress, which leads to destruction of the valves or connecting rod. This often happens due to improper filling or severe hypothermia.
How long does the compressor operate normally?
The operating time depends on the load of the refrigerator, the ambient temperature and other temperatures. Typically the operating cycle ranges from 10 to 30 minutes, followed by a pause. Inverter models can operate continuously at low speeds.