How a refrigerator works LG: device and principle of operation

Modern refrigerators of the South Korean company LG have long ceased to be just boxes for storing food, having turned into complex electronic-mechanical complexes. Understanding exactly how your LG refrigeratorworks allows you not only to operate it correctly, but also to promptly diagnose faults before they lead to damage to products. All models, be it a classic two-chamber unit or a premium one, are based on the classic compression cycle, but the brand’s engineering solutions make their own adjustments. InstaView, the classic compression cycle is based, but the brand’s engineering solutions make their own adjustments.

The main difference between LG equipment is the widespread implementation of distributed distribution systems cooling inverter compressors and distributed cooling systems Multi Air Flow. If in older models cold air was supplied only from the freezer, here many sensors and dampers create a uniform temperature background. This ensures the preservation of moisture in the products and there is no need for manual defrosting.

In this article we will analyze in detail the physical processes occurring inside the housing, consider the role of each unit and answer questions that often arise among owners. You will learn why the unit can hum, how the freshness zone works and what happens if the electronics fail.

The main refrigeration cycle and the role of the refrigerant

The fundamental operating principle of any LG refrigerator is based on the ability of the refrigerant (freon) to absorb heat during evaporation and release it during condensation. The cycle begins in the compressor, which compresses the freon gas, dramatically increasing its temperature and pressure. After this, the hot gas enters the condenser (grid on the back wall), where it cools and turns into a liquid state, releasing heat to the environment.

Next, the liquid refrigerant passes through a capillary tube or expansion valve, where the pressure drops sharply. It is at this moment that the substance is sharply cooled to temperatures below zero. Entering the evaporator located inside the housing, the freon boils and turns into gas, actively taking heat from the internal space of the chambers. This process is key to creating low temperatures.

Unlike older models, in modern LG units the cycle is often controlled by an intelligent board that regulates the operation of the compressor depending on the load. If you have opened the door frequently or loaded a lot of warm food, the system will increase the pumping power. In standby mode, the compressor does not turn off completely, but switches to minimum speed, which reduces wear on mechanical parts.

⚠️ Attention: The refrigerant in the system is under pressure. Puncture of pipes on your own or violation of the tightness of the circuit will not only disable the equipment, but can also be hazardous to health. Repairing the cooling system requires a license and special equipment.

It is important to note that the efficiency of the cycle directly depends on the cleanliness of the condenser. If the rear grille is clogged with dust, heat transfer is disrupted, and the compressor is forced to work hard to maintain the set temperature.

Specifics of the LG inverter compressor

The heart of most modern LG models is inverter linear compressor. In traditional refrigerators, the motor works on the “on-off” principle: it starts at full power, cools the chamber to the desired degree and turns off, after which the cycle repeats. Inverter technology works differently: the motor turns on once at startup and then simply changes the rotation speed.

This approach provides several critical advantages. Firstly, the absence of constant starting currents significantly extends the life of the motor. Secondly, the temperature inside the chambers fluctuates within a much narrower range, which is ideal for storing perishable foods. The noise from the operation of such a unit is minimal, since there is no characteristic relay click and startup hum.

Speed control is carried out by an electronic unit that receives signals from temperature sensors. If you place a hot pan in the chamber, the compressor will instantly increase speed. As soon as the temperature stabilizes, it will switch to an economical mode of maintaining cold. This makes the system operation Smart Inverter extremely efficient in terms of energy consumption.

• 🔹 Energy saving: Electricity consumption is reduced by 30-40% compared to classic models.
• 🔹 Low noise level: The absence of vibrations at start makes the unit operate almost silent.
• 🔹 Stability: The temperature of the products does not fluctuate, which preserves their structure and taste.
• 🔹 Warranty: LG often gives a 10-year warranty specifically for the compressor, which indicates reliability node.

No Frost system and air circulation

Technology No Frost (or Total No Frost in two-chamber models) eliminates the need for the user to defrost the refrigerator manually. The system is based on the principle of forced air circulation. Unlike static cooling, where the cold simply falls down, special fans work here, driving air masses through a complex system of channels.

The air passes through a hidden evaporator, where it is strongly cooled and dried. Excess moisture settles in the form of frost on the walls of the evaporator, and a dry and cold stream enters the chambers. This prevents the formation of a “fur coat” on the products and chamber walls. Periodically, based on a signal from a timer or algorithm, the system starts the defrost mode.

During defrost, the compressor and fan stop, and the Defrost heating element (heating element) turns on, which melts the accumulated ice. The melt water flows through the drainage channel into a special tray located above the compressor, where it safely evaporates. The user practically does not notice this process if the system is working properly.

Why do products dry in No Frost?

Dry air actively draws moisture from unprotected products. Therefore, in such refrigerators it is important to store food in containers or under film, otherwise cheese or sausage may spoil faster than in conventional models.

LG models often use a system Multi Air Flow, which involves the presence of many holes at different levels of the back wall. This allows cold air to be supplied evenly throughout the entire volume, avoiding the formation of warm zones in the corners.

Electronic control and sensors

A modern LG refrigerator is essentially a computer that controls the temperature. All processes are controlled by an electronic control board, which processes signals from many sensors. The main ones are thermistors installed in the freezer and refrigerator compartments, as well as the evaporator defrost sensor.

Thermistors change their resistance depending on the temperature. The board constantly monitors these readings. If you set +3°C, and the sensor shows +5°C, the controller commands the compressor to increase power. This accuracy makes it possible to achieve energy efficiency class A++ and higher.

The system also includes door opening sensors. If the door is left open for more than a certain time (usually 1-2 minutes), an audible alarm will sound and the indicator on the panel will light up. This prevents loss of cold and overload of the compressor. Some models have activity sensors that switch the refrigerator to a “smart” saving mode if the door has not been used for a long time.

⚠️ Attention: The electronics of LG refrigerators are sensitive to power surges in the network. If your area has unstable electricity, it is recommended to use a stabilizer or surge protector with surge protection.

Fault diagnosis is often carried out through the control panel itself. If any sensor or component breaks down, error codes may appear on the display (for example, Er FF - fan error, Er CF - communication error). Deciphering these codes allows the technician to quickly determine the essence of the problem without lengthy disassembly.

Freshness zone and additional functions

One ​​of the key features of LG refrigerators is the freshness zone, which in different models can be called Fresh Balancer, Moist Balance Crisper or Zero Degree. The principle of its operation is to create a microclimate that is different from the main volume of the chamber. The temperature is maintained here at about 0°C and high humidity, which is ideal for vegetables, fruits, meat and fish.

In boxes with the function Moist Balance the lid has a special porous structure. If the humidity is too high, condensation is absorbed into the lid; if it is low, the moisture evaporates back. This creates the effect of a “breathing” space where products do not dry out or rot from excess water.

Technology found in premium models DoorCooling+. In the upper part of the refrigerator compartment, behind the decorative panel, there are additional holes. When the door is opened, cold air, which usually evaporates upward, is retained and flows downward to the food lying on the door shelves. This speeds up cooling after loading and keeps it cold during frequent use.

• 🥦 For vegetables: High humidity preserves crunch and vitamins.
• 🥩 For meat: Low temperature (about 0°C) inhibits the growth of bacteria without freezing.
• 🧀 For cheese: A stable microclimate prevents weathering and mold.

Typical problems and their causes

Despite the reliability, LG equipment is not immune to breakdowns. One of the most common problems is the formation of an ice coat in the freezer or refrigerator compartment, despite the No Frost system. Most often, this indicates a malfunction of the defrost system: the heating element has burned out, the defrost relay is stuck, or the sensor has failed.

Another common problem is extraneous noise. If the humming noise changes to a knocking or grinding noise, the fan or compressor bearing may be worn out. Also, noise can occur due to the fact that the refrigerator is not level, and the vibration is transmitted to the body or floor.

If the refrigerator is working but not freezing, the reasons may be more serious: a freon leak or a blockage of the capillary system. In this case, the compressor may run non-stop, trying to gain temperature, but there will be no cold. It is also worth checking whether the air supply damper into the refrigerator compartment is frozen - a common problem when there is ice in the freezer, but it is warm above.

⚠️ Attention: If you notice that the back wall inside the refrigerator compartment is covered with a layer of ice or the “fur coat” is frozen, do not try to pick it out with a knife. This will lead to breakdown of the evaporator and gas leakage. Defrost the unit completely (for 24 hours with the doors open).

For independent initial diagnostics, you can perform a full defrosting cycle. If after 24 hours in the off state the problem (ice, smell, noise) disappeared, but appeared again after 1-2 weeks, it means that one of the system components (sensor, heating element, timer) is faulty. The part needs to be replaced.

Why does the LG refrigerator click loudly?

Clicks may be normal - this is the sound of the valves operating or the thermostat operating. However, loud clicks accompanied by an attempt to start and stop the compressor indicate problems with the starting device (in conventional compressors) or a malfunction of the inverter board.

What to do if the emergency temperature indicator is on?

Usually this means that it is too warm inside. Check if the door is closed tightly and if there is any product stuck. If the indicator lights up after loading warm food, wait a few hours. If it lights up constantly when the refrigerator is empty, diagnostics of the sensors is needed.

Is it possible to transport an LG refrigerator on its side?

It is strictly not recommended. When transported on its side or upside down, oil from the compressor may leak into the refrigerant circuit. This will cause water hammer when first started. If transportation is unavoidable, after installation, allow the refrigerator to stand upright for at least 4-6 hours before turning it on.