Failure of a compressor is one of the most serious and expensive breakdowns that the owner of refrigeration equipment may encounter. If you hear that your Atlant refrigerator hums, but does not cool, or the motor is completely silent when plugged in, there is a high probability that it is time to change the unit. Independent replacement of this unit requires not only technical skills, but also strict adherence to safety measures, since the work involves electricity and compressed gas.
Before you begin to dismantle the old one and install the new one motor-compressor, you need to make sure that you have special tools. You will need a pipe cutter, a soldering torch, a vacuum pump and a gauge station to charge the refrigerant. Without these tools, it will not be possible to do the job efficiently, and an attempt to save on equipment can lead to the final failure of the equipment.
In this article we will analyze the replacement process in detail, paying special attention to the electrical circuit and sealing of the system. It is important to understand that incorrect connection of contacts or violation of the soldering technology of copper tubes can result in a short circuit or freon leakage. Therefore, carefully study each step before starting work.
Fault diagnosis and selection of a new compressor
The first step is always an accurate diagnosis. The absence of cold does not always mean the death of the engine. Sometimes the problem lies in the start relay or thermostat. To check it yourself unit, you need to ring the windings with a multimeter. Normal resistance between the contacts indicates the integrity of the windings, but does not guarantee the serviceability of the mechanical part.
If you are convinced that replacement is necessary, you need to choose the right analogue. For refrigerators Atlant compressors of the SKO series or their foreign analogues from Danfoss (Secop) are often used. It is important to pay attention to the refrigerant your model operates with - it could be R600a (isobutane) or R134a. Using unsuitable oil or freon is unacceptable.
⚠️ Attention: Before purchasing a new compressor, be sure to check the model of your old unit and the type of refrigerant used. Installing a compressor designed for R134a in a system designed for R600a will lead to an explosive situation and failure of the system.
When choosing, also consider performance and overall dimensions. The new one motor must physically fit into the niche and have similar mounting holes. If you take an analogue, you may have to slightly modify the fasteners or use adapter bushings.
Necessary tools and preparation of the workplace
The quality of the work performed directly depends on the preparation. You will need not only a new compressor, but also consumables. Copper tubes for connections, solder, flux and the refrigerant itself should be on hand. Also, do not forget about a new filter drier, which must be changed whenever the system is opened.
To work with electricians, prepare screwdrivers, pliers and, preferably, a new start-protective unit (relay and starting capacitor), since old parts could be damaged if the motor breaks down. The workplace should be well lit and ventilated, especially if you plan to use an open flame for soldering.
- 🛠️ Set of tools for soldering: torch, gas cylinder, solder, flux.
- ⚡ Multimeter for checking electrical circuits and windings.
- 🔧 Pipe cutter, flaring tool and pipe cleaner.
- ❄️ Pressure gauge station and freon cylinder for refilling.
Provide access to the back of the refrigerator. It is best to roll out the unit to the middle of the room to have access from all sides. This will simplify the soldering process and visual inspection of connections. Do not forget to disconnect the refrigerator from the power supply before starting any manipulations.
Dismantling the old compressor and preparing the system
The process begins with removing the old unit. The first step is to bleed off any remaining refrigerant. To do this, a neat cut or puncture is made on the back wall, usually on the capillary tube or process pipe. The characteristic sound of the escaping gas will confirm that the pressure in the system has dropped.
Next, you should cut the copper tubes running from the compressor to the condenser and evaporator. Try to make cuts as far away from the solder as possible to leave a reserve of copper for new rolling. After disconnecting the tubes, remove the start relay cover and disconnect the electrical wires, having first noted or photographed their location.
Unscrew the mounting bolts or nuts holding the motor to the frame. Refrigerators Atlant often use rubber shock absorbers, which also need to be removed. Be careful when removing the old compressor, as technical oil may remain in it, which should not be spilled.
After removing the old motor, it is necessary to prepare the system for soldering the new element. Carefully strip the ends of the copper condenser and evaporator tubes. Use a brush or fine-grit sandpaper to remove oxides. A clean surface is the key to a sealed seam.
⚠️ Attention: When dismantling, do not bend the copper tubes of the capillary and discharge. Damage to thin-walled tubes will require complex replacement of sections, which increases the amount of work and the risk of errors.
Electrical diagram for connecting the Atlant compressor
The most crucial moment is connecting the electrical part. An error here can lead to burnt out windings or a fire. Standard single-phase motor has three outputs. They may not be labeled on the block, so it is important to identify them correctly.
Use a multimeter in resistance measurement mode. Measure the resistance between each pair of contacts. The greatest resistance will be between the starting and working windings. Less resistance is between the working winding and the common wire. The smallest is between the starting winding and the common wire.
| Pair of contacts | Resistance (Ohm) | Purpose |
|---|---|---|
| Working - Common | Average value | Working winding (Run) |
| Starting - General | Highest value | Starting winding (Start) |
| Working - Starting | Sum of the two previous ones | Total resistance |
One of the power wires (usually zero) is connected to the common contact, the phase through the thermal relay is connected to the working contact, the wire from the starting device is connected to the starting contact. In modern models Atlant a ready-made block is often used, where the wires are already routed by color, but checking with a multimeter will never be superfluous.
What happens if you mix up the starting and working windings?
If you apply power to the starting winding winding as if it were working, the engine may hum, but not start, or start in the opposite direction (which is critical for a piston compressor and will lead to valve failure).
Soldering copper tubes and installing a filter drier
Sealing the system is a key step. Brazing (usually copper-phosphorus) is used to connect copper tubes. First, the tubes are cleaned to a shine. Then flux is applied to them, and the joint is heated with a burner until cherry color.
It is important not to overheat the tube so that a burnout does not form, and not to underheat, otherwise the solder will not flow into the gap by capillary effect. The solder should melt from the heat of the tube, not from the flame of the torch. After soldering, the seam should be smooth and shiny, without holes or sagging.
Be sure to install a new one filter-drier. It removes moisture and oil breakdown products from the system. The filter is soldered into the gap of the condenser tube. Pay attention to the refrigerant flow direction arrow stamped on the filter housing. Installation with a filter, on the contrary, is unacceptable.
- 🔥 Heat the connection evenly on all sides before applying solder.
- 💧 Do not keep the system pipes open for more than 15 minutes to avoid moisture from the air.
- 🧪 Use only specialized flux for refrigeration equipment, do not use acid.
After soldering all connections, you must allow the system to cool. Wipe the solder joints with a damp cloth to remove any flux residue that may cause future corrosion. Visually check the seams for cracks.
☑️ Checklist before vacuuming
Evacuating and filling the refrigerator with freon
You cannot simply start the compressor after soldering - there is air and moisture left in the system. The air must be removed by vacuuming. Connect the vacuum pump to the process connection of the compressor. Turn on the pump and watch the pressure gauge.
Evacuation should last at least 30-40 minutes. The pressure gauge needle should go into the green zone (below zero). This will allow any moisture remaining in the pipes and oil to boil away. After turning off the pump, close the valve and wait 15 minutes. If the arrow does not creep up, then the system is sealed.
Now you can start refueling. The amount of refrigerant is indicated on a label inside the refrigerator compartment or on the rear wall. For Atlantov this is usually from 50 to 140 grams, depending on the model. You need to refill strictly by weight, since excess or lack of freon will disrupt the cooling cycle.
⚠️ Attention: The exact dosage of the refrigerant is critical. Excess freon will cause liquid fraction to enter the compressor, which will cause water hammer and destruction of the valves. The disadvantage is overheating and ineffective operation.
After refueling, solder the process pipe. Turn on the refrigerator and check operation. The condenser (grid at the back) should warm up evenly, and cold should appear in the evaporator. After a few hours, check the temperature in the chambers.
Common mistakes when replacing yourself
Many self-taught craftsmen make typical mistakes that nullify all efforts. One of the most common is neglecting vacuuming. An attempt to “blow through” the system with freon does not remove moisture, which turns into ice in the capillary and blocks circulation.
Another mistake is using the wrong solder or lack of flux. This leads to poor-quality seams that burst due to vibration or temperature changes. They also often forget to replace the starting relay, believing that since the motor is new, the old relay will do.
Incorrect sealing of the process pipe after refueling is another risk. If you leave the “tail” too long or, conversely, solder it too close to the compressor body, you can damage the pipe during the next service or interfere with heat dissipation.
- 🚫 Ignoring the vacuum time (less than 30 minutes).
- 🚫 Refilling "by eye" without using scales.
- 🚫 Using an old filter-drier.
- 🚫 Overheating of the compressor when soldering adjacent tubes.
Try to avoid haste. Repairing a refrigerator is a piece of jewelry work that requires precision. If you doubt your abilities at any stage, especially when working with gas and fire, it is better to turn to professionals.
Is it possible to use a car compressor for refilling?
No, conventional car pumps do not create the necessary pressure and are not designed for precise dosage of refrigerant. To refuel, you need a specialized refrigeration compressor or a cylinder with scales.
Control start-up and performance check
After completion of all work, the moment of truth comes. Plug in the refrigerator. In the first seconds listen to the sound. Startup should be smooth, without strong relay clicks or humming. After 5-10 minutes, the rear grille (condenser) should begin to heat up evenly.
Check operation in different modes. Allow the refrigerator to run a full cycle before shutting down. Make sure that ice has formed in the freezer compartment and that the temperature in the refrigerator compartment has dropped to +4...+5°C. The absence of frost on the evaporator or its uneven distribution may indicate problems with refilling.
Be sure to check for leaks. Wash the soldering areas with soapy water. The appearance of bubbles will indicate a leak. If everything is clean, you can install decorative covers and return the refrigerator to its place.
How long should the new compressor run when first started?
When first started after replacing the compressor and filling with freon, the refrigerator can operate continuously for 2-4 hours, gaining temperature. This is fine. The main thing is that it does not overheat (the temperature of the compressor housing should not exceed 90°C) and eventually enters an on-off cycle.
Is it necessary to flush the system when replacing a compressor?
Flushing the system with nitrogen or a special solvent is mandatory if the old compressor has burned out (“clogged” with soot) or if there was moisture in the system. If the compressor has simply stopped pumping mechanically, and the oil in the system is clean, thorough evacuation may be sufficient, but flushing with nitrogen will never be superfluous.
What type of oil should be poured into the Atlant compressor?
The type of oil depends on the type of refrigerant. For R134a freon, synthetic polyester oil (POE) is used, and for R600a, mineral or alkylbenzene oil is used. Mixing different types of oils is strictly prohibited, as they can clot and form a plug. A new compressor is usually already filled with oil, and there is no need to add anything if the system has not been flushed.