The situation when a loved one Biryusa refrigerator stops freezing, and an unpleasant smell appears inside or, conversely, food begins to melt, is familiar to many owners of this equipment. Often the cause is a refrigerant leak, and the owner is faced with a difficult choice: call a repairman or try to fix the problem himself. The refilling process requires not only special tools, but also a deep understanding of the thermodynamics of the refrigeration circuit.
It should immediately be noted that replacing freon in a domestic environment this is a procedure of increased complexity, associated with risks to the health and safety of the equipment itself. Unlike replacing a lamp or adjusting a thermostat, working with refrigerants involves breaking the tightness of the system, which requires subsequent professional soldering and vacuuming. If you do not have the skills to weld non-ferrous metals, further actions may only be a theoretical introduction for you.
Nevertheless, an understanding of the principles refilling the refrigerator is necessary for every competent user to monitor the quality of work performed by service departments or assess the feasibility of restoring old equipment. Modern models Biryusa can use different types of refrigerants, and an error in choosing a substance can damage the compressor forever. Let's look at this process in detail, step by step.
Diagnostics of leaks and preparation of equipment
Before taking active steps, you need to make sure that the problem lies precisely in the lack of refrigerant, and not a malfunction of the compressor or thermostat. If the motor hums, but there is no cold, and there is no uniform frost or ice on the evaporator, there is a high probability of depressurization of the circuit. Primary leak diagnostics is often carried out visually or using a soap solution, which is applied to suspicious sections of the pipeline.
To carry out the work, you will need a specialized set of tools, without which high-quality filling is impossible. It is critical to have a gauge station (manifold), a vacuum pump, a scale for accurate dosing, and a torch for soldering copper pipes. Using homemade methods, such as filling “by eye” or without vacuuming, will lead to the formation of an ice plug in the capillary pipe and rapid failure of the unit.
⚠️ Attention: Before starting any disassembly or soldering work, be sure to disconnect the refrigerator from the power supply. Working with exposed live parts of the compressor and using open flames near electrical wiring is deadly.
Particular attention should be paid to the type of refrigerant that was originally used by the manufacturer. Models Biryusa of different years of production could be fueled with R134a or R600a (isobutane). These substances are not interchangeable and require different approaches to installation and soldering. For example, isobutane is an explosive gas, which imposes additional safety requirements for working in confined spaces.
Necessary tools and materials
The quality of the work performed directly depends on the equipment of the workshop. For correct Freon refills it is not enough to simply have a gas cylinder. You will need a full set of professional equipment to monitor the pressure and cleanliness of the system. Saving on tools in this case leads to guaranteed defects.
The list of necessary equipment includes not only basic elements, but also high-quality consumables. Using cheap analogs of solder or low-quality tubes can lead to repeated leakage after a short time.
- 🛠️ Manometric manifold with a set of hoses (blue for low pressure, red for high).
- 🌀 Vacuum pump with a capacity of at least 2-4 cubic meters per hour to remove moisture.
- 🔥 Gas torch with a set of solder (silver or phosphorus-copper) and flux.
- ⚖️ Electronic scales with an accuracy of 1 gram for weighing the refrigerant.
- 🧪 Leak detector or ultraviolet lamp for searching micro leaks.
It is worth mentioning separately the importance of using nitrogen when testing the system. Injecting air with a compressor is unacceptable, since the moisture contained in the air will block the capillary tube when freezing, and oxygen will cause oxidation of the internal walls of the pipeline and combustion of oil in the compressor.
⚠️ Attention: When working with R600a refrigerant (isobutane) It is strictly forbidden to use tools that produce sparks. The room must be well ventilated, since the gas is heavier than air and accumulates below, creating an explosive concentration.
Also, do not forget to prepare copper tubes for extending the process rod and a new filter drier. Filter drier is a disposable element that must be replaced whenever the circuit is opened, as it absorbs moisture from the air instantly.
Removing the old refrigerant and searching for leaks
The process of restoring the refrigeration circuit begins with removing the remaining old gas and oil. Even if the system seems empty, excess pressure remains in it, which must be released through a puncture in the process tube. This must be done carefully so as not to damage the internal components of the compressor.
After releasing the pressure, you need to find the location of the leak. In factory conditions Biryusa refrigerators they are tested with helium, but in everyday life we are limited to visual inspection and a soap solution. Most often, leaks occur in soldering areas, on the evaporator (especially if it is built into the housing) or in the door heating circuit.
Where is the leak most often hidden?
The most problematic areas are the foamed evaporator inside the housing and the places where the tubes exit compressor. The defrost circuit that runs along the perimeter of the freezer is also often poisoned. If the leak is in the foamed part, repair becomes economically impractical, since it requires opening the housing or installing an external evaporator (crying).
To find hard-to-reach places, you can use the method of increasing the pressure with nitrogen to 6-8 atmospheres. This allows you to hear the characteristic swirl or see the inflating bubbles in the soap foam. However, be careful: excess pressure can lead to rupture of the thin-walled condenser tubes.
If a leak is found in an accessible place, the pipe is cleaned, degreased and sealed. If the evaporator hidden in the polyurethane foam is damaged, a decision is made to install a new evaporator (“crying”) or, in rare cases, to open the back wall of the refrigerator. The second option is less reliable due to the risk of breaking the thermal insulation.
Soldering components and replacing the filter drier
Soldering copper pipes is a skill that requires practice. For copper-to-copper or copper-to-steel joints (as in a compressor), different types of solder are used. It is important to heat the connection evenly so that the solder flows inward due to the capillary effect, and does not just envelop the pipe from the outside.
The key point is to install a new one filter drier. This component is responsible for removing moisture and microparticles from the system. An old filter, even if it looks intact, is already saturated with moisture from the air and will not be able to perform its function. It is sealed vertically, with an arrow in the direction of refrigerant flow (from the condenser to the capillary pipe).
During the soldering process, it is necessary to observe the temperature regime. Overheating can lead to the formation of an oxide film inside the pipe, which subsequently falls off and clogs the capillary. Underheating will lead to a leaky connection and repeated leakage.
| Component | Material | Solder type | Melting point |
|---|---|---|---|
| Copper pipe | Copper | Phosphorus-copper | ~700°C |
| Steel pipe (compressor) | Steel | Silver (30-40%) | ~750°C |
| Aluminum (rare) | Aluminium | Special. solder for Al | ~450°C |
| Brass valve | Brass | Silver | ~700°C |
After completion of all soldering work, the system must be sealed. The tightness test is carried out by pressure testing with nitrogen for several hours. If the pressure gauge does not show a drop in pressure, you can proceed to the next stage.
Evacuating the system
Evacuating is perhaps the most important stage, which is often ignored by beginners. The purpose of the process is to remove not only air, but also moisture vapor, which inevitably enters the circuit during soldering. Water in the system freezes at low temperatures, forming an ice plug in the capillary, which blocks the circulation of freon.
To create a vacuum, a special pump is used, connected to the service fitting. The process should last at least 30-40 minutes for household refrigerators. An indicator of high-quality evacuation is the reading of the pressure gauge in the vacuum zone (usually below -0.1 MPa or 750 mm Hg).
☑️ Evacuation checklist
There is a "torn" technique evacuation" when the pump is turned on and off several times, giving the system a "rest". This helps moisture evaporate from hard to reach areas and the compressor oil separator. However, for modern systems with isobutane a long continuous evacuation is sufficient.
After reaching a deep vacuum, the valve on the manifold is closed, the pump is turned off and the pressure gauge is observed for another 15-20 minutes. If the arrow does not move up, it means the system is sealed and ready for refueling. Any change in pressure will indicate poor-quality soldering.
Freon filling process and control
Refrigerator filling Biryusa is carried out strictly according to the weight indicated on the technical sticker (usually located inside the chamber or on the back wall). Using a weight cylinder is the only correct method. Charging “by pressure” or “by current” is a gross mistake, since these parameters depend on the ambient temperature and the condition of the compressor.
Freon is supplied to the system in the liquid phase (if the cylinder is turned over) or gas, depending on the type of refrigerant. For R134a and R600a it is important to control the quantity down to the gram. Overfilling will lead to an increase in condensation pressure and overload of the compressor, underfilling will lead to insufficient cooling.
⚠️ Attention: The exact filling dose for your model is indicated only on the nameplate. Do not rely on general tables on the Internet, since even for identical models Biryusa the dose may differ depending on the year of manufacture and the volume of the chamber.
After the calculated amount of gas has been introduced, the system is put into operation. The compressor should operate smoothly, without vibration. After 15-20 minutes, check the temperature of the condenser (grid at the back) - it should be warm or hot, and the temperature of the evaporator - it should be evenly covered with frost.
The final touch is to clamp and seal the filling tube. This must be done quickly to minimize the release of gas, and at a distance of at least 10 cm from the soldering point, so as not to damage the rubber shock absorbers of the compressor.
Frequently asked questions (FAQ)
Is it possible to fill the Biryusa refrigerator with R12 freon instead of R134a?
No, this is strictly prohibited. Refrigerants have different chemical properties, pressures and require different types of compressor oil. Mixing or replacing will lead to destruction of the compressor and a fire hazard.
How long should the refrigerator operate after refueling before cold appears?
The first signs of cooling should appear after 15-30 minutes of operation. Complete freezing of products and reaching the operating mode takes from 2 to 6 hours, depending on the load of the chamber and the ambient temperature.
Why does the compressor get very hot after refueling?
Strong heating may indicate overcharging of the system, the presence of air in the circuit (poor vacuum) or a malfunction of the compressor itself. It is necessary to check the pressure in the system and the current consumption.
Does the system need to be flushed with nitrogen before vacuuming?
A nitrogen pressure flush is recommended if there was burnt oil or a large leak in the system to force out contaminants. In standard cases, high-quality vacuuming is sufficient.