Understanding how it functions Position 172is necessary for every owner who wants to extend the life of the equipment and operate it correctly. This two-chamber unit, despite its accessibility, hides inside a rather complex engineering system that requires careful attention. Knowledge of the physical processes occurring inside the cooling circuit will help you quickly diagnose problems and avoid common mistakes when placing or loading products.
The basis of the entire system is a continuous cycle of converting the refrigerant from liquid to gas and back, which allows heat to be removed from the internal volume of the chambers. Unlike older models with manual defrosting, modern technology has been introduced here, requiring precise adjustment of thermostats and sensors. If you have ever wondered why the back wall is sometimes covered with frost, and then it disappears, then the answer lies precisely in the operating algorithms of the control electronics and the compressor.
In this article we will analyze in detail each component of the device, starting from the motor-compressor and ending with the condensate drainage system. Attention will be devoted not only to theory, but also to practical aspects that will help you assess the condition of your refrigerator without calling a technician. You will learn where exactly the cooling occurs and how the cold air flows are distributed between the freezer and refrigerator compartments.
The basic principle of operation of the refrigeration circuit
The heart of any refrigerator, including the model Pozis RK-172, is a closed circuit, according to through which the refrigerant circulates. Most often, modern modifications use environmentally friendly gas R600a (isobutane), which has excellent thermodynamic properties. The circulation of the substance occurs due to the operation of the compressor, which creates the necessary pressure, pushing freon through the tubes of the condenser, capillary tube and evaporator.
The cooling process begins with the fact that the gaseous refrigerant is compressed in the compressor, heating up significantly. Next, the hot gas enters the condenser coil, usually located on the rear wall or built into the side walls of the housing. Here, heat exchange occurs with the environment: the gas cools down and turns into a liquid state, giving off excess heat to the kitchen.
- ❄️ The compressor compresses the refrigerant, increasing its pressure and temperature.
- 🌡️ In the condenser, the hot gas cools and turns into liquid.
- 💧 Passing through the capillary tube, the pressure drops sharply and the liquid boils.
- 🌀 In the evaporator, the refrigerant actively absorbs heat from the chambers, becoming a gas again.
A critical element is the capillary tube, which serves as a choke. It is in this unit that a sharp decrease in pressure occurs, due to which liquid freon, entering the evaporator, instantly boils at a very low temperature, which provides a powerful cooling effect. After passing through the evaporator, the gas is again absorbed by the compressor and the cycle repeats. The boiling point of isobutane at low pressure can reach minus 30-40 degrees Celsius, which provides a powerful cooling effect. After passing through the evaporator, the gas is sucked back into the compressor and the cycle repeats.
⚠️ Attention: If you notice that the condenser tubes (usually the grille at the back) remain cold when the compressor is running, this may indicate a freon leak or a clogged system. Operating in this mode will lead to overheating of the motor.
No Frost system and air circulation
The model Position 172 is equipped with a system No Frost (or complete), which fundamentally distinguishes it from devices with a drip defrosting system. In these refrigerators, the evaporator is hidden behind a plastic panel, usually located on the back wall of the freezer. Cooling of products occurs not due to direct contact with cold walls, but due to forced circulation of air masses.
A special fan is responsible for this process, which drives cold air from the evaporator through channels into both chambers. In the refrigerator compartment, air enters through special openings, and in the freezer compartment it is evenly distributed throughout the entire volume. This allows you to avoid the formation of an ice crust on products and walls, since moisture does not have time to freeze on the surface, but is discharged into the drainage system.
Periodically, based on a signal from a timer or sensor, the system switches to defrosting mode. At this moment, the compressor and fan are turned off, and the heating element (heating element) located under the evaporator is turned on. The frost accumulated on the evaporator fins melts, and the resulting water flows into a special pan, from where it evaporates naturally due to the heat of the operating compressor.
What will happen if the water drainage channel becomes clogged?
If the drainage hole or channel becomes clogged with ice or debris, water will begin to accumulate under the evaporator. Over time, this can cause an ice block to form that blocks the fan or damages the plastic parts of the case. It is also possible that water may appear at the bottom of the refrigerator compartment.
Design and functions of the compressor
Refrigerators Pozis most often install compressors from trusted manufacturers, such as Atlant, Secop (formerly Danfoss) or Chinese analogues. These are sealed units, inside of which there is an electric motor and a piston group. When voltage is applied, the engine rotor begins to rotate, driving the piston, which compresses the refrigerant.
It is important to understand that the compressor operates in pulse mode. It turns on when the temperature inside the chambers rises above the set threshold, and turns off when the set mode is reached. The duration of operation and downtime depends on many factors: quantity of products, room temperature, frequency of door openings and serviceability of seals.
| Parameter | Description | Normal value |
|---|---|---|
| Power | Engine energy consumption | 100-140 W |
| Refrigerant | Type of gas used | R600a (Isobutane) |
| Mode work | Work-rest ratio | 30-40% work, 60-70% rest |
| Noise level | Sound pressure at a distance of 1 m | Up to 40 dB |
If the compressor runs continuously without turning off for hours, this is an overload signal. The reason may be an insufficient amount of freon, a leak in the circuit or a violation of thermal insulation. Overheating the compressor housing (when it is impossible to touch it with your hand for more than 2-3 seconds) is an alarming symptom that requires immediate intervention.
Electronic control and thermoregulation
Modern modifications Position 172 can be equipped with both mechanical and electronic thermostats. In electronic versions, the control unit is responsible for temperature control, which receives data from temperature sensors (thermistors) located at different points in the chambers. This allows you to maintain the temperature with high accuracy, minimizing differences.
The user sets the desired temperature using the control panel, often located on the outside of the door or inside the refrigerator compartment. The electronics analyzes the sensor readings and makes a decision to turn the compressor and fan on or off. The system also controls the defrosting process, turning on the heating element only when it is really necessary.
- 🔌 The temperature sensor of the refrigerator compartment controls the general climate.
- 🧊 The evaporator sensor monitors the degree of freezing to start defrosting.
- ❄️ Temperature sensor The freezer compartment monitors the freezing mode.
If the sensors or control unit malfunction, the refrigerator may go into emergency mode. This is often accompanied by flashing indicators or a sound signal. Electronic board sensitive to power surges in the network, therefore, to extend its service life, it is recommended to use a stabilizer or surge protector, especially in areas with unstable power supply.
⚠️ Attention: Technical characteristics and location of sensors may vary depending on the year of manufacture and the specific modification of the model. Always check the technical documentation supplied with your device, or look for the diagram on the nameplate inside the camera.
Typical faults and their impact on operation
Even a reliable one is not immune from breakdowns that disrupt the standard operating algorithm. One of the most common problems is the failure of the thermostat or defrost sensor. If the thermostat “sticks” in the “on” position, the compressor will work without interruption, trying to achieve unattainable cold, which will lead to severe freezing of the chambers and excessive consumption of electricity. Pozis refrigerator is not immune from breakdowns that disrupt the standard operating algorithm. One of the most common problems is the failure of the thermostat or defrost sensor. If the thermostat “sticks” in the “on” position, the compressor will work without interruption, trying to achieve unattainable cold, which will lead to severe freezing of the chambers and excessive consumption of electricity.
Another common problem is a malfunction of the No Frost system fan. If its blades become overgrown with ice or the motor burns out, air circulation stops. As a result, the temperature in the freezer may be normal (near the evaporator), but in the main chamber it may be too high, and food will begin to spoil. A characteristic sign is the absence of fan noise when the compressor is running.
☑️ Diagnosis of cooling problems
Refrigerant leakage is a more serious problem that requires professional repair using special equipment. In this case, the compressor will work constantly, but no cooling will occur at all, or it will be very weak. Leaks often occur in places where tubes are soldered or in the foamed part of the body (aluminum evaporator), which makes repairs difficult and expensive.
Operating rules for stable operation
In order to refrigeration unit serve for a long time and efficiently, it is important to follow simple operating rules. Do not load hot products into the chambers - this creates excessive load on the compressor and upsets the temperature balance. Also, you should not fill the refrigerator to capacity with food, blocking the ventilation holes through which cold air circulates.
Regular defrosting, despite the No Frost system, is still recommended at least once a year for general cleaning and checking the condition of the seals. Dirt and mold on the sealing rubber bands lead to a loose fit of the door, the entry of warm air and increased formation of ice. Wipe the seals with a soft cloth dampened in a mild soap solution.
Watch the noise level. The appearance of new sounds - gurgling, metallic clanging or humming - may indicate problems with the compressor mounting, foreign objects in the fan area, or wear on the motor bearings. Timely detection of these signs will allow you to eliminate the problem at an early stage.
Why does the Pozis 172 refrigerator hum loudly?
The hum can be caused by vibration of the case against the wall or furniture, improper installation (the legs are not adjusted), or wear of the compressor. If the humming is accompanied by a knocking noise, the engine shock absorbers may need to be replaced.
How often should the compressor turn on?
Under normal conditions, the compressor should operate approximately 30-40% of the time (about 10-15 minutes of operation, 20-30 minutes of rest). If it turns on too often or works without stopping, check how tightly the door is closed and the temperature in the room.
Is it possible to transport the Pozis refrigerator lying down?
It is highly not recommended. When transporting lying down, there is a risk of tubes tearing off the compressor or oil leaking into the refrigerant circuit, which will lead to water hammer when first turned on. If transportation cannot be avoided, after installation, allow the refrigerator to stand upright for at least 24 hours.
What to do if it is too cold in the refrigerator compartment?
Check the thermostat settings. If the sensors are working properly, the problem may be that the air duct damper is stuck in the open position, which causes excess cold air from the freezer to enter the main chamber.