Modern Pozis refrigerator is a complex thermodynamic system, the effectiveness of which depends on the coordinated operation of many components. Understanding exactly how cooling occurs helps not only to operate the equipment correctly, but also to quickly diagnose possible malfunctions. The process is based on the circulation of a refrigerant, which removes heat from the products and releases it into the environment.
This process is continuous and cyclical as long as the device is connected to the mains. Regardless of whether your model Pozis RK-139 or a more modern version with the system No Frost, the basic physical principle remains unchanged. The key element of the cycle is the change in the state of aggregation of freon when passing through nodes with different pressures. It is the evaporation and condensation of gas that allows you to maintain a low temperature inside the chambers.
Many users mistakenly believe that cold is “created” inside the chamber, but in fact, heat is simply “pumped” out. If you have ever touched the rear grill of a running unit, you have felt heat - this is the energy taken from the food. Let us analyze in detail which units are responsible for this process and how they interact with each other using the equipment of the Russian brand.
The main units of the refrigeration circuit
The heart of any refrigeration unit, including products from the plant in the city of Elabuga, is compressor. This electromechanical device creates the necessary pressure to move the refrigerant in a closed circle. Pozis models most often use piston motors that pump gaseous freon, increasing its temperature and pressure before sending it to the condenser.
After the compressor, the hot gas enters condenser - this is the same black grille located on the back wall, or hidden tubes built into the side walls of the housing. Passing along a long coil, the substance releases heat into the room and gradually cools, passing from a gaseous state to a liquid one. This process is called condensation, and it is critical to the efficiency of the entire system.
Next, the liquid refrigerant passes through a filter drier, where residual moisture is removed from it, preventing the formation of ice plugs. The flow then enters a capillary tube, a very narrow channel where the pressure drops sharply. It is this pressure difference that allows freon to boil at low temperatures, entering the evaporator.
It is important to monitor the condition of the condenser, since contamination with dust reduces heat transfer. If you see that the rear grille is covered with a layer of lint or pet hair, performance may drop by 20-30%. Regular cleaning behind your refrigerator is an easy way to extend the life of your compressor. Pozis may fall by 20-30%. Cleaning behind your refrigerator regularly is an easy way to extend the life of your compressor.
⚠️ Warning: Never attempt to clean the condenser or back panel with a damp cloth while the appliance is plugged in. This may result in a short circuit or electric shock.
The role of the compressor and refrigerant in the cycle
The compressor in Pozis refrigerators operates in pulse mode, turning on according to a signal from the thermostat or electronic control module. When the temperature inside the chambers rises above the set value, the electrical circuit is closed and the motor starts. Modern models are often equipped with inverter or energy-efficient compressors, which are quieter and consume less electricity.
R600a (isobutane) or R134a gases can be used as a working fluid (refrigerant) in various equipment. Isobutane is more environmentally friendly and economical, but requires special care during repairs due to its flammability. R134a less effective, but safer and inert. Replacing one type of freon with another without completely reconfiguring the system is unacceptable and will lead to breakdown.
Gas circulation is strictly regulated by design. First, the compressor sucks in cold gas from the evaporator, compresses it, and the hot stream goes into the condenser. After passing through the capillary expander, where the pressure drops from high to low, the freon enters the evaporator. There it boils, taking heat from the internal volume of the refrigerator.
The efficiency of this process directly depends on the amount of refrigerant in the system. A freon leak is one of the most common reasons why a refrigerator stops freezing. Unlike cars, there is no “topping up” fluid; in the event of a leak, a search for the location of the damage is required, evacuation of the system and refilling with a strictly standardized amount of gas.
Differences in cooling systems: Static, Drop and No Frost
Pozis equipment is available in various modifications, and the principle of cold distribution in them can differ significantly. The simplest models use static system (Direct Cool). In it, cold air falls down naturally, and the evaporator is located directly on the back wall of the refrigerator compartment. This leads to the formation of a “snow coat”, which has to be defrosted manually.
More advanced drip system (often labeled as Auto Defrost) automates the process of defrosting the evaporator. In this case, the rear wall of the refrigeration chamber periodically heats up (during the compressor stops), and the frozen ice melts, flowing into a special tray under the compressor, where it safely evaporates. The user only needs to periodically wash the camera, but not remove the ice.
The most modern and convenient system is No Frost (found in models of the Mir i Shikariseries). Here the evaporator is hidden and located behind a back panel, usually in the freezer compartment or between the compartments. The fan forces dry cold air throughout the entire volume. In such refrigerators, ice does not form at all, since moisture is blown out of the chambers and settles on a hidden evaporator, from where it is removed by the defrosting system.
- ❄️ Static system: requires manual defrosting 1-2 times a year, food can dry faster.
- 💧 Drip system (Drop): automatic defrosting refrigerator compartment, the freezer still needs to be defrosted manually.
- 🌬️ No Frost: full automation, no ice and frost, uniform temperature, but noisier operation due to the fan.
The choice of system affects not only convenience, but also energy consumption. Models with No Frost require more electricity to operate the fan and defrosting heating elements, but provide better food preservation due to stable temperature conditions.
Control system and thermoregulation
Thermostat or electronic control unit is responsible for maintaining the set temperature. Pozis mechanical models use a capillary thermostat, the sensitive bulb of which is located inside the chamber. When the volume of gas in the flask changes (due to temperature changes), the contacts close or open, turning the compressor on or off. thermostat (thermostat) or electronic control unit. Pozis mechanical models use a capillary thermostat, the sensitive bulb of which is located inside the chamber. When the volume of gas in the flask changes (due to temperature changes), the contacts close or open, turning the compressor on or off.
In electronic models, control is carried out microprocessor. It reads the readings of temperature sensors (thermistors) located in different areas of the refrigerator and makes a decision about starting the equipment. This allows you to implement functions such as “Super Freeze”, “Vacation” or precise digital adjustment of degrees.
If the thermostat fails, the refrigerator may either not turn on at all, or work without interruption, freezing food to the point of stone. Electronic modules are more reliable, but their diagnostics require special equipment. Often, a malfunction of the electronics can be corrected by rebooting (disconnecting from the network for 15 minutes).
Why is the temperature indicator blinking?
The blinking indicator on the control panel of the Pozis refrigerator usually signals that the temperature in the chamber has risen above the permissible threshold. This may be caused by warm food being loaded, the door not being closed properly, or a faulty sensor. If the blinking does not stop after the camera cools down, diagnostics are required.
It is important to understand that the thermostat settings depend on the time of year. In summer, when the room is hot, the compressor has to work harder, so it is recommended to set average values so as not to overload the motor. In winter, if the refrigerator is in an unheated room, the mechanical thermostat may simply not turn on, since it will “seem” to it that it is already cold inside.
⚠️ Attention: Do not set the minimum temperature (maximum power) unless absolutely necessary. This leads to increased wear on the compressor and excessive energy consumption, and products may deteriorate due to overdrying.
Ventilation and circulation of air masses
In models with forced air circulation, fanplays a key role. It is located in the freezer compartment and blows cold air through special channels into the refrigerator compartment. The air passes through a filter system (on some models), which helps eliminate unpleasant odors and bacteria.
The air duct system is designed to ensure uniform cooling of all shelves. However, there is a risk of the products blocking the outlet openings. If you tightly pack the refrigerator with bags right at the back wall or at the air supply holes, circulation will be disrupted. This will result in one part of the chamber being too cold and another too warm.
In addition, proper ventilation is important for the compressor compartment itself. If the refrigerator is built into a niche or stands close to the wall, heat removal from the condenser and motor is disrupted. The instruction Pozis recommends leaving gaps of at least 5-10 cm on the sides and back for free air convection.
| Parameter | Static system | No Frost system | Drop |
|---|---|---|---|
| Ice formation | On the back wall and products | Absent (hidden evaporator) | Only on the hidden evaporator |
| Humidity in the chamber | High (products dry more slowly) | Low (products may air out) | Medium/High |
| Noise level | Low (motor hum only) | Medium (fan running) | Low |
| Defrosting | Manual (2 times a year) | Automatic | Automatic (cold chamber) |
Violation of product placement rules is a common cause of user complaints. You should not place hot pots, but packing the camera tightly to capacity is also harmful. The air must flow freely around the products in order to effectively remove heat from them.
Typical problems in operation and their causes
Understanding the principle of operation helps to quickly identify anomalies. If the refrigerator Pozis hums louder than usual, this may indicate wear on the compressor bearings or improper installation (misalignment of the housing). If the humming gives way to gurgling or hissing, this is normal, the refrigerant is leaking.
The lack of cold when the engine is running often indicates a freon leak or a clogged capillary tube. In this case, the compressor works in vain, trying to pump gas that is small or cannot pass through a narrow cross-section. Diagnosis of such malfunctions requires calling a technician with a pressure gauge manifold.
The constant formation of a “coat” in the refrigeration chamber of a model with a drip system may indicate a loose door fit or a malfunction of the defrost heater. If the defrost sensor is “stuck”, the heating element will not turn on, and the ice will not melt, blocking the air channels.
☑️ Diagnostics
You should remember that some sounds and phenomena are normal. The clicking sound when turning on and off is the work of the relay. The water under the refrigerator (in the tray) is the result of the defrost system. Understanding these nuances will save you from unnecessary panic and unnecessary service calls.
Frequently asked questions (FAQ)
Why does the Pozis refrigerator take a long time to gain temperature after the first turn on?
When first started or after long-term transportation, the refrigerator takes time (from 4 to 12 hours) to temperature stabilization. The massive walls and food inside must cool down. If the temperature does not drop to the set values during the day, it is worth checking the thermostat settings.
Is it possible to transport the Pozis refrigerator lying down?
Transporting it lying down is possible, but not advisable. If you had to transport the equipment in a horizontal position, after installation it cannot be turned on for at least 4-6 hours (or better yet, a day). The oil from the compressor must drain back into the crankcase, otherwise water hammer and engine failure are possible.
What does the flashing “Alarm” indicator or red eye mean?
This is an alarm about an increase in temperature in the freezer or refrigerator compartment. Most often, the reason is that you forgot to close the door tightly, loaded a lot of warm food, or there was a power surge. If the indicator does not go off after cooling, the temperature sensor may have failed.
How often do you need to defrost a Pozis refrigerator with the No Frost system?
The No Frost system means that ice does not freeze on food and walls, so regular defrosting to remove ice is not required. However, it is recommended to carry out hygienic washing of the chambers 1-2 times a year to remove bacteria and odors, after first disconnecting the device from the network.