Refrigerators Atlant are deservedly popular due to their reliability, but even time-tested equipment requires attention to detail. The heart of the cooling system here is thermostat, which is responsible for maintaining the specified temperature regime. It is this component that makes the decision to turn the compressor on or off, based on the readings of temperature sensors inside the chambers.
An understanding of the operating principle of this unit is necessary for any owner who wants to extend the life of the unit. If the mechanism fails, food may spoil and the compressor will run continuously, causing it to overheat. In this article we will analyze in detail the design of the thermostat, its interaction with other components of the system and methods for identifying faults.
It is important to realize that a thermostat is not just a switch, but a complex mechanical or electronic device. Its task is to accurately control the boundaries of the temperature corridor. Violation of these limits signals the need for diagnostics or replacement of the control element.
The main function of the thermostat in the cooling system
The main task of the thermostat in the refrigerator Atlant is the automatic opening and closing of the electrical power supply circuit of the compressor. This happens depending on the air temperature inside the refrigerator or freezer. When the temperature rises above the set value, the contacts close, starting the motor.
The process occurs cyclically, providing a stable climate for storing products. Thermoregulator continuously reads data from the sensing element and compares them with the settings set by the user through a rotary knob or electronic panel.
If the mechanism is stuck in the “on” position, the compressor will work continuously, trying to cool the chamber to unattainable values. Otherwise, when stuck in the “off” position, the refrigerator will stop cooling and the temperature inside will begin to rise to room temperature.
⚠️ Attention: Operating a refrigerator with a faulty thermostat in continuous operation can lead to compressor failure and burnout of the start relay.
Modern models can use electronic sensors, but classic ones Atlanta are often equipped with mechanical regulators. Their operating principle is based on the physical properties of substances that expand or contract when temperature changes.
Design of a mechanical thermostat: internal circuit
The classic mechanical thermostat installed in refrigerators Atlantis a sealed system filled with gas or gas-filled mixture. The main part of the design is a bellows (accordion), which reacts to changes in pressure inside the capillary tube.
The design includes several key elements that ensure accuracy of operation:
- 🌡️ Sensing tube (capillary), which is filled with freon or other refrigerant and placed in a cooled zone.
- ⚙️ Bellows chambertransmitting gas pressure to the lever mechanism for switching contacts.
- 🔌 Electric contacts, opening the circuit when a certain point is reached.
- 🔧 Adjusting spring, the tension of which is changed by turning the control knob.
The principle of operation is based on the Gay-Lussac law: when heated, the gas in the capillary expands, increasing the pressure on the bellows. The bellows, in turn, unbends and through a system of levers opens the contacts, turning off the compressor.
When cooling, the pressure drops, the spring compresses the bellows, and the contacts close again. The critical feature is that the length capillary tube is strictly designed for a specific refrigerator model, and its shortening is unacceptable. This will lead to a complete loss of sensitivity of the device.
Differences between mechanical and electronic regulators
In the model range Atlant there are both old proven mechanical systems and modern electronic analogues. Mechanical thermostats are simple and maintainable, but have less accuracy.
Electronic thermostats use thermistors, the resistance of which varies depending on the temperature. The signal is processed by a microprocessor, which controls the compressor with high precision.
A comparison of the characteristics of two types of systems is presented in the table below:
| Characteristics | Mechanical thermostat | Electronic regulator |
|---|---|---|
| Control accuracy | ±2-3°C | ±0.5°C |
| Service life | 10-15 years | 7-10 years |
| Maintainability | High (replacement) | Low (unit replacement) |
| Sensitivity | Depends on gas pressure | High, digital |
Electronics allows you to implement additional functions, such as the "Vacation" mode or fine tuning for each camera separately. However, mechanics remain more resistant to power surges in the network.
Why are mechanics more reliable?
Mechanical thermostats are not afraid of power surges and network interference, since they do not have complex electronics. Electronic units often fail due to sudden changes in voltage in the electrical network, requiring an expensive replacement of the control module.
Typical signs of a malfunctioning thermostat
You can determine what thermostat in your Atlanta is not working correctly by a number of indirect signs. The most obvious symptom is the absence of cold when the compressor is running or, conversely, continuous operation of the motor without shutdowns.
Pay attention to the following manifestations:
- ❄️ Food in the refrigerator the chamber freezes or, on the contrary, quickly deteriorates.
- 🔊 The compressor works "to wear out", without pausing for more than 40-50 minutes.
- 💡 The light in the chamber is on, but there is no cold (if the compressor is silent).
- 🧊 A “snow coat” or ice crust forms on the back wall of the refrigerator compartment.
Sometimes the problem lies not in the device itself, but in the displacement of the capillary tube. If it has moved away from the evaporator wall, the sensor will read the incorrect air temperature, not the surface.
⚠️ Attention: Before replacing the thermostat, make sure that the capillary tube is pressed tightly against the evaporator. Loose fastening is a common cause of incorrect operation.
It is also worth checking the adjustment knob. In some models, it can idle without changing the tension of the spring inside the housing.
Algorithm for checking the thermostat with a multimeter
For accurate diagnosis, you need to ring the contacts of the thermostat using multimeter. Before starting work, you must turn off the power to the refrigerator by unplugging the plug from the socket.
Sequence of actions when checking:
- Get to the thermostat by removing the protective plastic cover or the top cover of the refrigerator.
- Disconnect the wires from the contacts of the device, having previously memorized or photographed the connection diagram.
- Set the multimeter in resistance measurement mode (Ohm).
- Touch the thermostat contacts with the probes.
If the thermostat is working properly and is in a warm state, the device should show "0" (short). When placing the sensitive tube in the freezer (or with strong cooling), the resistance should become infinite (open circuit).
☑️ Thermostat diagnostics
It is also important to check the breakdown on the housing. One probe is placed on the contact, the second on the metal body of the device. The device should not show resistance.
Replacing the thermostat: step-by-step instructions
If diagnostics confirm a malfunction, the only solution is All that remains is to replace the unit. For refrigerators Atlant it is important to choose an analogue with identical parameters, especially the length of the capillary tube and temperature range.
The replacement process requires care:
First you need to dismantle the old device by unscrewing the mounting screws and carefully removing the capillary tube from the mounting hole. Be careful not to damage the tube or allow freon to leak from the system if it passes through the evaporator.
The new thermostat is installed in the reverse order. The capillary tube must be secured in the same places where the old one was fixed, using standard clamps. Incorrect bending of the tube can lead to its fracture.
After connecting the wires according to the diagram, assemble the case and turn on the refrigerator. The initial startup may take up to several hours to reach the mode.
⚠️ Attention: Do not bend the capillary tube at an acute angle and do not allow it to be pinched. This can disrupt the circulation of the filler gas and damage the new thermostat.
After installation, it is recommended to carry out a test cycle of operation, monitoring the temperature in the chambers using an external thermometer.
Frequently asked questions (FAQ)
Is it possible to temporarily close the thermostat contacts to make the refrigerator work?
Yes, this is possible for a short-term check of the compressor or as an emergency measure. However, in this mode the refrigerator will operate continuously, which will lead to deep freezing of food and possible freezing of the evaporator. in this mode it is prohibited.
How to understand that the Atlant thermostat is stuck?
If when you tap on the regulator body or turn the knob you hear a click and the compressor changes operating mode (turns on or off), it means the contacts are stuck or oxidized. This is a temporary phenomenon, but it indicates an imminent breakdown.
Is a thermostat from another refrigerator suitable for Atlant?
Only if the mounting dimensions, capillary tube length and temperature response range match. There are no universal solutions, since different models Atlant require different temperature cut-off parameters.
Why does the refrigerator not turn off for a long time after replacing the thermostat?
Perhaps the new regulator has a different temperature range or the capillary tube is not installed deep enough in channel. Also, the reason may be a lack of freon in the system, which requires checking by a specialist.