Refrigerant leakage is a common problem in the operation of refrigeration equipment. The elimination of this malfunction is usually entrusted to masters specializing in the restoration of the performance of refrigeration equipment.
But refilling the refrigerator with freon is quite affordable for home craftsmen who are willing to carefully study this process and put knowledge into practice.
The content of the article:
- The role of freon in the refrigerator
- Causes of refrigerant leakage
The order of the work on the replacement of freon
- Step # 1 - diagnose the problem yourself
- Step # 2 - Preparatory Work Before Replacing
- Step # 3 - remove refrigerant residues
- Step # 4 - perform freon injection
- Conclusions and useful video on the topic
The role of freon in the refrigerator
If some compressor is considered the heart of the refrigerator, then the refrigerant can be considered as blood. Without a sufficient amount of this substance, no refrigeration equipment can work. Colorless and odorless gas is needed to move thermal energy.
Freon easily goes from a liquid to a gaseous state at relatively low temperatures. The contour through which it circulates consists of two parts: internal and external.
Liquid refrigerant enters the internal contour of the refrigerator and absorbs particles of thermal energy scattered in the air, turning into gas. It then moves to the external circuit, passes through the compressor and the evaporator, transfers heat to the surrounding air, and returns to liquid form.
The cycle is repeated again and again, as a result, the air in the refrigerator chamber becomes colder and the rear wall grill constantly generates heat.
To fill the refrigerator with freon, you need a filling station, a set of special tools and materials, as well as a cylinder with refrigerant.
These properties of freon are used in other devices, such as air conditioners, heat pumps, etc. Gas circulates in a hermetically sealed circuit. It does not pose a great danger to human health even with the complete leakage of the substance from the ordinary household refrigerator.
In total, the industry uses 16 types of these saturated fluorinated hydrocarbons. For filling a specific model of the refrigerator, one brand of freon is suitable, usually it is indicated directly on the compressor housing.
Causes of refrigerant leakage
In short, the cause of freon leakage is a violation of the tightness of the refrigerant circuit. But the causes of this situation can be very different. Accidental mechanical impact on the elements of the refrigerant circuit or on the compressor can cause such a malfunction.
The breakdown of the compressor almost inevitably necessitates pouring freon. Even if the refrigerant remains in the circuit at the same time, it will still have to be charged when replacing the faulty element. The poor quality of the capillaries, along which freon moves, or their wear also often causes depressurization of the system.
If the joints of the individual elements of the refrigerant circuit are not correctly mounted, they may weaken over time, the refrigerant will flow out through the cracks that appear.
If the contamination of the capillary tubes is due to the freezing of moisture inside the circuit, it is not difficult to clean them. But sometimes such a blockage occurs as a result of the accumulation of contamination from particles of burnt engine oil. The filter drier does not pick up these substances, they gradually accumulate inside the narrow tubes and form an obstacle to the free circulation of the refrigerant.
If a broken compressor needs to be replaced with a new one, it will be necessary to open the refrigeration circuit and, after replacing, to perform the download of a new portion of freon
Although the freon leak in such a situation is not observed, in order to normalize the system, you will have to open the refrigerant circuit.
After cleaning the capillaries will have to restore its integrity, and then enter into the system a new refrigerant to replace the lost.
Before starting work on refueling, identify the cause of the leak and repair it. To do this, you need to inspect the contour to understand exactly where this is going.
In order to identify the place of freon leakage with the help of soap solution, it is necessary to investigate the condition at the joints of the tubes, as well as where there are visible traces of oil
If the inspection results did not give, you can use a soap solution. At the same time air is supplied to the system under slight pressure.
A soap solution is applied to the surface of the tubes, connections, etc. It will bubble up in places of leakage. Processing the entire circuit in this way is inexpedient and unsafe.
It will be easier to first check the weakest and most suspicious areas: joints, as well as areas where there are traces of contamination with technical oils.
To accurately determine the point of damage to the circuit and refrigerant leakage, a leak detector is used - a device that responds to a specific brand of freon.
If the soap solution did not produce results, a leak detector should be used to determine the location of the refrigerant leakage or invite an experienced technician. This is not a universal instrument; a particular instrument is usually set to respond only to a certain brand of refrigerant.
It can be used to identify leaks not only before fixing them, but also after the end of the circuit refueling to make sure that the quality of the operations performed is high enough.
If this is not done, you can miss some shortcoming. Poor repair will manifest in about two weeks, all work will have to be done anew.
In addition to eliminating leaks, it also does not hurt to check the functioning of other elements of the system. Insufficient amount of freon often leads to increased wear of individual parts. If you do not eliminate the causes that cause a leakage, you will soon have to start repairing again, inject refrigerant, etc.
The order of the work on the replacement of freon
Before proceeding with the replacement of the refrigerant, you must make sure that you have all the necessary tools and materials for the work at hand.
Step # 1 - diagnose the problem yourself
Refrigerants do not burn, but their absence or insufficient amount in the system can cause early wear and damage to other parts.
In addition, the violation of the specified heat transfer will cause the refrigerator to become too warm, the products will be spoil, unpleasant smell, etc. Therefore, it is important to learn how to quickly detect signs of leakage and eliminate their.
The presence of snow inside the refrigerator compartment may be a sign of a malfunction, especially if the snow cap reappears after defrosting.
Here are some points to pay close attention to:
- the temperature inside the chamber is too high;
- markedly reduced interruptions in the engine;
- the compressor runs continuously;
- condensation occurs inside the device;
- a foul odor emanates from the refrigerator that is not associated with the presence of spoiled products;
- the evaporator is covered with a snow hat or ice, etc.
Sometimes a leak can be detected right away. If inadvertently removing ice from the evaporator, the contour tube can be accidentally pierced.
As a result, gas will emerge from the narrow opening with a characteristic hiss. If you pay attention to this point, you can quickly fix the problem.
Corrosion of the hull may be a sign of a lack of refrigerant in the circuit: the temperature inside the chamber rises, condensate accumulates, moisture acts on the metal, rust appears
Step # 2 - Preparatory Work Before Replacing
Before starting repair work, of course, the refrigerator should be disconnected from the power supply. All heaters and sources of open fire should be turned off or removed away from the place where the filling is done freon.
Electrical equipment that will be used during repair must be grounded in accordance with the instruction manual.
When carrying out the soldering should also take care of fire safety. Although freon is not dangerous for people, nevertheless it is better to air the room during and also at the end of the work.
First of all, be sure to disconnect the refrigerator from the network and prepare the entire set of necessary tools.
Before the start of the repair, it doesn’t hurt to find and re-read the operating instructions for the refrigerator to take into account the specific features of the specific model. When refilling the refrigerator with freon, you should be guided by the information indicated on the tag, as well as by the marks on the filling cylinder.
Step # 3 - remove refrigerant residues
Before you pump gas into the system, you need to remove the remaining coolant from it. To do this, you need to find a filter drier, it is clamped using a needle grip.
After that, a hole is made in the filter in the area of copper. An item damaged in this way will have to be replaced with a new one.
When charging with refrigerant the filter drier will be damaged, it will have to be replaced with a new serviceable element. In addition, you need to unsolder the circuit and install additional valves
Place for soldering the valve is better to prepare in advance. It must be removed from the nozzle and cut off the extra length. Then it is recommended to immediately solder the valve to the compressor.
After refrigerant residues leave the system, all pipes will need to be purged with nitrogen. This will allow to remove moisture from the circuit, which may have got there.
For gas injection into the working circuit of the refrigerator, a Schroeder valve is installed, which prevents the outflow of freon in the opposite direction.
Do not use cylinders for such work, in which the gas pressure exceeds 6 atmospheres, as the system can be damaged. Details of the internal pressure are usually indicated on the container.
If a cylinder with suitable characteristics is not available, it is necessary to supply gas to the system using a reduction gearbox.
On the cylinder with refrigerant indicated brand of freon, as well as working pressure. If the gas inside is compressed to more than six atmospheres, a reduction gear should be used.
The system needs to be purged for about 10-15 minutes. After that, the valve on the needle grip block and cut off the filter next to the capillary tube.
Then you must purge the circuit again. At the end of the purge, you need to install a new drain filter instead of the used one.
This should be done within 15 minutes after the end of the last purge, since the refrigerant circuit cannot be left open for a longer period.
Professional masters use for this type of work a whole set of special tools: leak detector, tester, vacuum pump, wrenches, thermometer, pliers, pinch pincers, etc.
To perform soldering, stock up with protective screens, you also need a Schröder valve and a new filter drier.
To perform a one-time refueling of the refrigerator, it does not make sense to buy a separate set of equipment. It is cheaper and easier to rent everything you need.
Step # 4 - perform freon injection
To perform this operation, you need tools that allow you to control the pressure in the system. Household appliance repairmen use a filling station consisting of two pressure gauges with shut-off valves and three hoses.
Pressure gauges vary in color: red and blue. With the first, the discharge pressure is measured, and blue determines the suction pressure.
This is a simplified diagram of the connection of the filling station and the refrigerant cylinder to the refrigeration circuit. In this embodiment, the red hose and pressure gauge is not used.
When working with a conventional household refrigerator usually only take into account the readings of the blue manometer.
The hoses to which the pressure gauges are attached also have different color markings: red and blue, which are connected to pressure gauges of the same color, and yellow, located in the center.
Before starting work, you must make sure that the valves on the hoses with pressure gauges are completely blocked. After that, the yellow hose is attached to the gas cylinder.
The blue hose is connected to the pipe through which the refrigerant will flow into the circuit. To do this, use a special fitting.
The red hose is mounted at the other end of the system. For it you need to attach a Schröder valve.
Blue gauge is needed to control the suction pressure, red - to monitor the pressure at the outlet of the system, freon is fed through a yellow hose from a cylinder
When all the necessary elements are connected, you need to open the stop valves on the blue and red hoses. After that, open the valve on the cylinder with refrigerant and begin filling the system, watching the readings of the pressure gauges.
When the pressure reaches about 0.5 atmospheres, the pressure gauge valves should be shut off.
Now they supply power to the compressor for about 30 seconds. Instead of a cylinder, a vacuum pump is connected to the yellow hose. It includes about 10 minutes.
Evacuation allows you to remove the air trapped in the system and improve the quality of refueling. Now you need to re-attach the yellow hose to the cylinder with freon.
A vacuum pump is necessary in order to remove any extraneous gases from the refrigerant circuit and to ensure high-quality refueling.
In doing so, make a small gap between the collector and the hose so that the incoming refrigerant displaces air from the hose and apply a small amount of gas to the hose.
Then the yellow hose, from which the air is vented, is securely fixed to the manifold. Again, you need to open the blue valve and continue filling the circuit with freon.
At this stage, the compressor is switched on again and the gauges are monitored to ensure that the system is operating normally. If the pressure remains stable, the nozzles are bent and carefully sealed.
Do not pinch the service port and solder it before performing a test start of the system. At this stage, the blue gauge should always be in the vicinity of zero.
At home, when charging the system with freon, household scales can be used to control the amount of refrigerant transferred to the circuit.
Some craftsmen carry out the filling circuit with freon using only one pressure gauge. In this case, the amount of refrigerant that has been moved to the circuit is determined by weighing the cylinder with freon on household scales.
The rest of the download process is almost the same as the method described above.
Conclusions and useful video on the topic
Here is the process of eliminating leaks and injecting freon into the refrigerator using weights:
The general procedure for performing this type of work can be viewed in the video:
It is relatively easy to fill the refrigerator with freon if you have the necessary equipment and relevant skills. However, it is necessary to take into account a number of nuances: to comply with safety requirements, to identify and eliminate all faults that caused refrigerant leakage, perform the final soldering, etc. Inexperienced masters should first observe the work of specialists to learn how to perform this operation. on their own.