Failure of the motor-compressor is one of the most serious and expensive malfunctions that the owner of household appliances may encounter. If you have made a firm decision to replace the unit yourself, you have to go through a difficult path, requiring not only theoretical knowledge, but also the availability of specialized tools. Incorrect connection Atlant refrigerator compressor can lead to instantaneous combustion of the windings or an explosive situation, so each step must be performed with maximum precision.
Modern models, especially those equipped with inverter motors or the No Frost system, have a more complex electrical circuit compared to classic single-chamber ones “Sviyagami” or early models of the brand. Before you begin dismantling old equipment, you need to clearly understand the type of your refrigerant (R134a or R600a), since the soldering technology and requirements for system tightness depend on this. Ignoring these nuances often becomes the reason that the new unit does not work correctly or fails in the first hours of operation.
In this article we will analyze the replacement process in detail, paying special attention to the electrical connection and starting-protective equipment. You will learn how to correctly identify the contacts, connect the starting relay and perform the initial engine start without the risk of damaging the system. Remember that working with refrigerants and electricity requires compliance with safety precautions, and the lack of tightness in the connections reduces all efforts to zero.
Diagnostics and preparation for replacing the compressor
The first step should always be an accurate diagnosis, confirming that the problem lies in the motor, and not in the control circuit or thermostat. If Atlant refrigerator it hums but does not start, or starts for a few seconds and clicks, most likely the compressor itself or the start relay is faulty. However, before purchasing a new spare part, you need to make sure that the motor windings are not “pierced” to the housing and to each other, for which a multimeter is used.
Checking the resistance of the windings is a key point. Normal values for different models may differ, but usually the resistance of the starting winding is higher than the working winding. If the device shows infinity or, conversely, zero, the engine requires replacement. It is also important to check if there is a short circuit to the housing: one probe of the multimeter is placed on the stripped section of the copper tube, and the second one on the contacts in turn.
⚠️ Attention: Before starting any work on disassembling the electrical part, be sure to disconnect the refrigerator from the mains! Even briefly touching live contacts during diagnosis can lead to serious injury.
After confirming the diagnosis, it is necessary to prepare the workplace. You will need access to the rear niche of the unit where the motor is located. If the model is built-in, it will have to be completely removed from the furniture niche. Prepare a new compressor in advance, which must be strictly the same marking or an approved analogue recommended by the manufacturer for your refrigerator model.
Necessary tools and materials for work
High-quality replacement of the compressor is impossible without specialized equipment. Unlike simply replacing the thermostat, here you will have to work with copper pipes and gas. The main tool will be a torch for soldering copper pipes, operating on an oxygen-propane mixture or using acetylene. Regular POS-60 solder and flux should also be on hand, but for modern systems it is better to use silver solder.
A critical step is vacuuming the system. This requires a vacuum pump and a manifold. An attempt to start the refrigerator without creating a deep vacuum will result in the moisture and air remaining in the system freezing in the capillary tube, causing an ice jam and failure of the new compressor.
- 🔧 Tools: pipe cutter, rolling, pliers, side cutters, screwdrivers, multimeter.
- 🔥 Equipment: gas burner, nitrogen cylinder (for purging), vacuum pump, pressure gauge station.
- 🧪 Consumables: solder (silver or copper-phosphorus), flux, refrigerant (R134a or R600a), filter drier.
- 🧤 Protection: gloves, goggles, respirator (when working with gas).
Special attention should be paid to the filter-drier. This element required changes every time the refrigerant circuit is opened. The old filter is already saturated with moisture and will not be able to perform its function, which will quickly lead to corrosion of the internal parts of the compressor and clogging of the capillary system.
☑️ Preparation for soldering
Removing the old compressor and preparing the pipes
The process of removing the old unit begins with removing the protective casing at the bottom of the refrigerator. It is usually secured with latches or bolts. After removing the cover, you will see the compressor attached to the frame by four metal studs with rubber dampers. Carefully unscrew the nuts holding the motor, but do not remove it completely until you have unsoldered the tubes.
Before soldering, you must bleed off the coolant. In a factory setting, this is done in a fume hood, but at home, you can simply cut the filling tube with pliers (usually it has a characteristic bend and a sealed end). The gas will come out with a characteristic whistle - this is normal. After bleeding the gas, you can begin to unsolder the suction and discharge tubes.
When heating copper connections, it is important not to overheat the compressor housing itself or the adjacent plastic elements of the refrigerator. Use a damp cloth to cool nearby areas. After unsoldering the tubes, remove the old compressor from the frame. Now you need to prepare the new unit: remove the transport plugs from the pipes and, if the new compressor contains transport oil, it is better to replace it or make sure that its quantity corresponds to the norm.
⚠️ Attention: Never open the fittings of a new compressor ahead of time. Air and moisture instantly get inside, oxidizing the windings. Remove the plugs immediately before soldering.
Connection diagram of the electrical part and relay
The most crucial moment for an amateur electrician is the correct connection of the contacts. On the body of each compressor (including Atlant) there is a diagram or marking of the terminals: S (Start), R (Run - working) and C (Common). The start-up protection relay is placed directly on the terminals of the compressor, and its position is strictly regulated (usually marked “UP” upward).
If you are changing the compressor, it is better to also replace the old relay with a new one, corresponding to the engine power. The connection takes place via a terminal block. It is important not to mix up the wires: the phase wire usually goes to the common contact, and the starting winding is switched through the relay. An error in the connection will lead to humming and subsequent burning of the winding in a few seconds.
Color marking of wires
In different modifications of Atlant refrigerators, the colors of the wires may differ. Standard circuit: Red - Phase (L), Blue/Black - Zero (N), Yellow-green - Ground. However, always rely on the diagram printed on the relay itself or on the motor housing, and not just on the color of the insulation.
To check the correct assembly before soldering, you can conduct a short test run. Connect the plug to the mains and start the engine. It should work smoothly, without strong vibration. If the motor hums and does not start, immediately turn off the power - it means the relay is faulty or the contacts are mixed up.
Soldering connections and installing a filter drier
Soldering copper tubes requires skill. First, the tubes are cleaned to a shine with fine sandpaper. A new filter drier is then placed on the suction tube. Pay attention to the refrigerant flow direction arrow on the filter housing - it should point towards the compressor (suction). The filter is soldered into the gap of the capillary tube or capacitor.
The soldering process looks like this: we heat the joint evenly with a torch, then add solder. It should flow into the gap under the influence of droplet forces and the temperature of the copper, and not melt from the burner flame. A quality connection looks smooth and shiny. A copper tube leading to the condenser is also soldered onto the discharge tube (outlet from the compressor).
It is important to monitor the temperature. If you overheat the soldering joint, the copper may burn out or the insulation of the wires inside the compressor may melt. After the connections have cooled, it is necessary to check their tightness. To do this, the system is filled with nitrogen under low pressure and checked for bubbles with a soap solution.
Evacuation of the system and charging with refrigerant
After successful soldering and checking for leaks, the evacuation stage begins. A pressure manifold and a vacuum pump are connected to the service fitting (which you previously welded to the process tube of the compressor). The pump turns on for 15-30 minutes. The goal is to remove all air and water vapor from the system.
The pressure in the system should drop to a deep vacuum (the pressure gauge needle will go into the negative zone). After turning off the pump, you need to turn off the valve and watch the arrow for 15-20 minutes. If the arrow creeps up, it means that there is a micro-leak in the system, and the soldering needs to be redone.
Refrigerant charging is carried out only after creating a vacuum. The weight doses of refrigerant for refrigerators Atlant are indicated on the nameplate (usually from 60 to 140 grams). Overfilling or underfilling will lead to improper operation of the refrigerator. Gas is refilled in the liquid phase (cylinder upside down) or gas, depending on the type of freon and the manufacturer's recommendations.
The table below shows approximate refilling parameters for popular series:
| Refrigerator series | Type refrigerant | Charging dose (g) | Suction pressure (Bar) |
|---|---|---|---|
| Atlant MXM-1700 | R134a | 110-120 | 0.8 - 1.0 |
| Atlant MXM-2808 | R134a | 95-105 | 0.6 - 0.8 |
| Atlant MXM-4000 | R600a | 60-70 | 0.4 - 0.6 |
| Atlant No Frost | R134a | 130-145 | 1.0 - 1.2 |
⚠️ Attention: The exact data on the type and amount of refrigerant is always indicated on the factory sticker located inside the refrigerator compartment or on the back wall. Use only the parameters specified there.
First start-up and monitoring of system operation
After refueling, it is necessary to hermetically seal the filling tube. Now you can carry out the first full launch. Plug in the refrigerator and listen. Operation should be quiet, without knocking or strong vibration. After 10-15 minutes, the suction tube (included in the compressor) should begin to cool and become covered with dew or light frost.
Heating of the compressor is normal. The case can heat up to 70-90 degrees Celsius. However, if it becomes red hot or cannot be held by your hand for more than 2 seconds, turn off the device immediately. This is a sign of overheating due to improper refueling or ventilation problems.
Monitor operation during the first 24 hours. The refrigerator should reach temperature and turn off according to the thermostat signal. If the operating cycle is continuous for more than 2-3 hours without shutting down, the seal may be broken or the amount of refrigerant is selected incorrectly.
Why does the compressor heat up?
The compressor is a heat pump. When gas is compressed, the temperature inevitably increases. However, excessive heating often indicates that there is air left in the system (which does not condense and creates excess pressure) or the capillary is clogged.
Common mistakes when replacing them yourself
Many self-taught craftsmen make typical mistakes that negate the result of the repair. The most common of them is neglecting to replace the filter drier. Saving on this element leads to repeated repairs after a few months.
Another mistake is using the wrong oil. Compressors for R134a and R600a freon are filled with synthetic oil (POE polyester or polyvinyl chloride), which is hygroscopic (absorbs moisture). If you fill in mineral oil from an old R12, the system will quickly clog and fail. It is also dangerous to leave the system open to air for more than 15 minutes.
- ❌ Ignoring vacuum: Starting without a vacuum pump is guaranteed to kill the compressor with moisture.
- ❌ Wrong solder: using tin without silver for high-temperature components.
- ❌ Mixed-up relays: installation of a relay from a different model, which leads to burnout of the starting winding.
- ❌ Lack purging with nitrogen: oxidation of the tubes from the inside during soldering.
Refrigerator repair Atlant with your own hands is a complex technical process that requires responsibility. If you are not confident in your soldering skills or do not have a pressure gauge station, it is better to entrust this work to professionals, since the cost of an error (new compressor + gas + work) can exceed the cost of factory repairs.
Is it possible to replace an Atlant compressor with an analogue from another brand?
Yes, it is possible, but subject to a number of conditions. The analogue must have a similar or greater capacity (in Watts or BTU), the same type of refrigerant and oil, as well as the corresponding overall and mounting dimensions. Replacements with Danfoss (Secop) or Embraco compressors are popular, but they may require replacing the start relay.
How much does it cost to replace a compressor in a service compared to DIY?
The cost of a new compressor is about 60-70% of the price of the entire service. Self-replacement saves the cost of work, but requires the purchase of expensive equipment (pump, burner, station), which will only pay for itself with regular repairs.
Why does a new compressor hum loudly after installation?
There may be several reasons: vibration from the pipes touching the housing or other parts, incorrect installation of shock absorbers, or defective compressor itself. Also, a hum can occur due to improper soldering, if a solder leak has formed inside, narrowing the passage.
Is it necessary to flush the system when replacing a compressor?
Flushing the system with nitrogen is mandatory if the old compressor has burned out and black carbon and acid remain in the system. In this case, it is also necessary to install an additional suction filter, which is removed after 24 hours of operation.