Modern household appliances produced by the Minsk plant Atlanthave long established themselves as a reliable and energy-efficient solution for storing food. A special place in the model range is occupied by units equipped with two compressors, which radically distinguishes their design from simpler single-circuit systems. Understanding the principles of operation double-engine circuit is necessary for every owner for competent operation, timely detection of faults and extending the service life of equipment.
Unlike standard models, where one powerful compressor drives the refrigerant throughout the entire volume, two independent motors are installed here. Each compressor is solely responsible for its own evaporator and temperature circuit, which allows you to independently regulate the climate in the freezer and refrigerator compartments. This architecture eliminates the flow of odors between compartments and increases the overall efficiency of the cooling system, making it more resistant to voltage fluctuations and loads.
Let us examine in detail exactly how the elements of this system interact and why the presence of two “hearts” in the refrigerator often becomes a decisive factor when choosing equipment. We will look at the physical processes of compression, condensation and evaporation of freon, as well as the role of electronics in controlling these processes.
Principal diagram of a dual-circuit cooling system
The fundamental difference between a two-compressor refrigerator Atlant lies in the division of the refrigerant into two independent streams. If in single-circuit models freon passes sequentially through the freezer and refrigerator compartment, here the system is divided into two closed cycles. The first circuit serves freezer compartment, providing deep freezing, and the second - refrigerator compartment, maintaining positive temperatures for fresh products.
Each of these circuits has its own compressor, condenser (often they are combined into one radiator, but the input and output are separate), a capillary tube and an evaporator. This means that the failure of one motor does not lead to complete defrosting of the entire refrigerator. Moreover, this scheme allows the use of different types of refrigerants or different operating modes for each circuit, although in household models Atlant usually one type of freon (R600a or R134a) is used for both circuits.
⚠️ Attention: Attempting to connect one compressor to two evaporators without special shut-off valves and complex automation will lead to system failure. The dual-circuit design requires strict separation of hydraulic paths.
The independence of the circuits also means that heat transfer between the chambers is minimized. When you open the refrigerator door, warm air enters only this circuit, and the refrigerator compressor starts to compensate for the heat without affecting the operation of the freezer. This significantly saves energy and reduces wear and tear on mechanical parts.
The compressor operating cycle: from suction to discharge
To understand how the system works, you need to consider the physics of the process inside itself piston unit. The compressor in the refrigerator Atlant is a sealed block, inside of which there is an electric motor and a compression pair (cylinder and piston). The process begins from the moment when the thermostat or electronic sensor sends a signal to start.
At this moment the piston begins to make reciprocating movements. During the suction stroke, low-pressure refrigerant vapors from the evaporator are drawn into the cylinder through the inlet pipe. Then the gas is compressed: the volume decreases, and the pressure and temperature increase sharply. The heated gas under high pressure is pushed through the discharge valve into the condenser, where it cools and turns into liquid.
- 🔄 Suction: The piston lowers, creating a vacuum, and gaseous freon fills the cylinder through the inlet valve.
- 🔨 Compression: Piston rises, valve closes, the volume of gas decreases, the pressure rises to 10-15 atmospheres.
- 💨 Discharge: The pressure overcomes the resistance of the outlet valve, and the hot gas goes into the condenser pipeline.
- 🛑 Pause: After reaching the set temperature, the sensor opens the circuit and the engine stops until the next cycle.
In a two-compressor system, these cycles occur asynchronously. While one motor is resting, the second one can actively work, equalizing the temperature after loading the products. This load is distributed more evenly compared to one powerful compressor, which is forced to work at its limit.
The role of thermostats and starting automation
Control of two independent motors requires a double set of control electronics. Each circuit has its own thermostat (or temperature sensor in models with electronic control), which controls the climate in a specific chamber. It is this element that makes the decision to start or stop the compressor.
The connection diagram includes a starting relay and a thermal protection relay. The starting relay is necessary for short-term connection of the motor starting winding in order to create torque and start the rotor. As soon as the engine picks up speed, the relay turns off the starting winding. The thermal relay protects electric motor windings from overheating: if the current exceeds the norm or the compressor cannot start for a long time, the bimetallic plate opens the circuit, preventing the motor from burning out.
In models Atlant with system No Frost control can be carried out by an electronic module. In this case, mechanical thermostats are replaced by resistance sensors, and starting relays are often built directly into the compressor housing or are made in the form of solid-state elements (PTC starters). This increases the reliability of the system, as it eliminates mechanical wear of the contacts.
What is a PTC starter?
A PTC starter (posistor) is a thermistor that, when voltage is applied, heats up and sharply increases its resistance, opening the circuit of the starting winding. This is a reliable alternative to mechanical relays with contacts that can burn out.
Comparison of performance and energy efficiency
Many users mistakenly believe that two compressors consume twice as much electricity. However, the practice of operating refrigerators Atlant shows the opposite. Two low-power engines operating in optimal mode are often more economical than one powerful one, which is forced to work with overload or switch on/off.
Energy efficiency is achieved by precisely matching the compressor power to the volume of the cooled chamber. The refrigerator motor has less power than the freezer motor because maintaining +4°C requires less energy than maintaining -18°C. In single-circuit systems, a powerful compressor is often “underloaded” when working only on the refrigeration chamber, which reduces its efficiency.
Below is a comparative table of characteristics demonstrating the differences in the operation of the systems:
| Parameter | Single compressor | Two compressors |
|---|---|---|
| Independence of chambers | No (common refrigerant) | Complete independence |
| Noise level | Higher (a powerful motor hums louder) | Lower (small motors are quieter) |
| Freezing speed | Medium (resource is shared) | High (separate circuit) |
| Risk of defrosting | High (if it breaks, everything melts) | Medium (one camera works) |
It is also worth noting the service life. Small compressors experience less mechanical stress during startup, which has a positive effect on the durability of the crank mechanism. However, the number of moving parts in the system doubles, which theoretically increases the probability of failure of one of the nodes, although statistics from service centers Atlant speaks of the high reliability of both types.
Diagnostics of faults in a two-compressor system
Diagnostics of a refrigerator with two motors has its own specifics. The first sign of a problem is often a change in the nature of the sound or rhythm of operation. If one of the compressors hums but does not start, or runs continuously without shutting down, this is a signal of malfunction. It is important to be able to distinguish which circuit is malfunctioning.
The check should begin with a visual inspection and listening. Place your hand on the compressor housing: if it is hot, but the refrigerator does not freeze, the piston group may have jammed or a freon leak has occurred. If the engine is cold and silent, the problem may be in the start relay, thermostat or wiring. Electrical circuit Each compressor should be checked with a multimeter for an open or short circuit.
- 🔊 Loud knocking: indicates wear on the crankshaft bearings or destruction of the valve group inside the hermetic unit.
- ❄️ Weak cooling: if one chamber is warm and the other is working normally, check the thermostat of the non-working zone.
- 💡 Indicator flashing: in electronic models Atlant The error code on the display will indicate a specific sensor or a malfunction in the compressor circuit.
- 🔥 Overheating: if the motor body is hot to the point where it is impossible to hold your hand, the thermal relay has tripped or the heat exchange in the condenser is disrupted.
⚠️ Attention: It is strictly forbidden to open the sealed compressor casing at home. Inside there is oil and refrigerant under pressure. Repair is only possible by replacing the entire unit, followed by vacuuming and charging the system.
☑️ Diagnostics before calling a technician
Features of maintenance and extending service life
Although compressors Atlant do not require regular lubrication (oil is filled at the factory and circulates in the system), they are sensitive to operating conditions. The main enemy is overheating. Make sure that the refrigerator is installed at a distance of at least 5-10 cm from the wall to ensure free circulation of air around condenser radiator.
Regular defrosting (for drip systems) or cleaning the drainage channels (for No Frost) helps maintain efficient heat transfer. If the evaporator becomes coated with ice, the compressor has to work longer to break through the insulation layer, which leads to its overload. In dual-compressor systems, this is especially critical, since a violation of the heat dissipation in one circuit can indirectly affect the overall temperature background inside the cabinet.
It is also important to monitor the cleanliness of the rear panel. Dust, animal hair and fluff, settling on the radiator grille and in the compressor area, create a heat-insulating layer. This forces the motors to work harder. Simple vacuuming every six months can extend the life of equipment by several years.
Frequently asked questions (FAQ)
Is it true that two compressors are louder than one?
No, this is a common myth. In fact, two small compressors are usually quieter than one large one. They create less vibration, and their operating sound has a higher frequency, which resonates less with the furniture and room. Modern models Atlant equipped with additional sound insulation.
Is it possible to replace one compressor with a more powerful one?
It is strictly not recommended. The system is designed for a strictly defined cooling capacity. Installing a more powerful motor will lead to freezing of the evaporator, a violation of the temperature regime and rapid failure of the new compressor due to frequent starts or operation without shutting down.
Why does one compressor work and the second is silent?
This is a normal situation if the temperature has already been reached in one chamber, but not in the other. Also, the second compressor may not turn on due to a malfunction of its thermostat, start relay, or an open circuit. If the “silent” chamber is warm, diagnostics are required.
How many years do compressors in Atlanta last on average?
If the operating conditions are observed (stable voltage, cleanliness at the rear, timely defrosting), the average service life of compressors is 10-15 years. There are units that work for more than 20 years, but this depends on the quality of service and conditions in the electrical network.