The refrigerator is one of the most important household appliances in every home, ensuring the safety of food. However, few people think about what happens inside the case after you slam the door. The heart of this entire complex system is compressorwhich causes the refrigerant to circulate in a closed circuit. It is thanks to this device that heat is removed from the chambers to the outside, creating the necessary cold.
Understanding the operating principles of this unit helps not only to better operate the equipment, but also to notice signs of impending breakdowns in time. In this article we will analyze in detail the physics of the process, types of engines and the nuances of their maintenance. Knowledge of the device will help you avoid unnecessary expenses on repairs or purchasing a new unit.
The physical basis of the operation of the refrigeration circuit
The basis of the operation of any refrigerator is a thermodynamic cycle that includes four main components: a compressor, a condenser, an evaporator and a capillary tube. Compressor here acts as a pump that compresses the refrigerant gas, increasing its pressure and temperature. After this, the hot gas enters the condenser, where it cools and turns into liquid.
Next, the liquid freon passes through a narrow capillary tube, where its pressure drops sharply. Once in the evaporator, the refrigerant boils at low temperatures, actively absorbing heat from the internal space of the chambers. This process of converting liquid into gas is the very moment when direct cooling of products occurs.
⚠️ Attention: Any manipulations with a sealed circuit, including replacing the compressor or refilling freon, require special equipment and skills. Self-repair can lead to complete failure of the equipment.
The cycle is repeated until the thermostat registers that the set temperature has been reached. It is important to understand that the efficiency of the entire system directly depends on the serviceability motor-compressor. If this unit operates intermittently, cooling will be uneven or stop altogether.
Design and design motor-compressor
Structurally, a household compressor is a sealed metal casing, inside which an electric motor and the pumping mechanism itself are located. All these elements are immersed in a special refrigeration oilwhich lubricates the rubbing parts and removes some of the heat. This design is called sealed, since it does not require disassembly at home.
Inside the casing, the engine shaft is rigidly connected to the crank mechanism, which drives the pistons. As the shaft rotates, the pistons perform reciprocating movements, sucking gas from the evaporator and pumping it into the condenser. To reduce vibration and noise, the motor is suspended on springs inside the housing.
- 🔧 Housing: Performs the function of protection from dust, moisture and mechanical damage, and also serves as a resonator to reduce noise.
- ⚙️ Electric motor: Converts electrical energy into mechanical energy, starting the gas compression process.
- 💨 Piston group: Directly compresses the refrigerant, creating a pressure difference in the system.
- 🛡️ Start-protective relay: Automatically starts the engine and turns it off when overloaded or overheated.
The service life of modern models can reach 10-15 years or more with proper operation. However, the resource greatly depends on the quality of the voltage in the electrical network and the ventilation conditions around the device.
Varieties of compressors: from classics to inverters
There are several types of compressors on the household appliances market, each of which has its own design features and operating principle. Until recently, the most common units were piston units operating on the principle of reciprocating motion. They are reliable, but create a certain level of noise and vibration.
More modern are inverter models that are able to smoothly regulate the speed of rotation of the engine shaft. Unlike traditional on-off systems, the inverter simply reduces speed to maintain temperature. This allows you to save energy and extend the service life of the mechanism.
There are also linear compressors in which there is no crank mechanism. The piston movement is carried out by electromagnetic forces, which makes them very quiet and durable. Such devices can often be found in premium technology.
| Compressor type | Noise level | Energy consumption | Operating life |
|---|---|---|---|
| Piston | Medium / High | Standard | 7-10 years |
| Inverter | Low | Economical | 10-15 years |
| Linear | Very low | Highly economical | 15+ years |
The choice of compressor type affects not only the price of the refrigerator, but also the comfort of its use. Inverter and linear models are more expensive, but pay for themselves due to silence and energy savings.
The role of the starting relay and thermostat
Starting a powerful compressor electric motor requires a significant starting current, which is several times higher than the operating one. To control this process, starting relayis used. Older models use relays with a posistor, while new ones use electronic modules that provide a softer start.
Temperature control is carried out using a thermostat or an electronic sensor. When the temperature in the chamber rises above the set value, the circuit closes and the compressor receives a command to start. When the desired cold is reached, the circuit opens.
What is a thermal protection relay?
This device protects the motor windings from combustion. If the current in the circuit exceeds the norm or the compressor overheats, the thermal relay opens the contacts, stopping the motor until it cools down.
Failure of any of these elements leads to the fact that the compressor either does not turn on at all or works nonstop, trying to cool the chamber. Often it is a burnt-out relay that causes a breakdown, although the engine itself may be fully operational.
⚠️ Attention: Frequent clicks when trying to start the refrigerator often indicate a faulty start relay or a problem with the motor windings. Do not ignore these sounds.
Typical faults and their symptoms
Understanding how the compressor works helps diagnose problems faster. The most common cause of failure is turn-to-turn short circuit the motor windings. This leads to the fact that the motor hums, but does not start, or knocks out automatic fuses in the electrical network.
Another common problem is loss of performance. The compressor runs constantly, but the temperature in the chambers does not drop to the required values. This may be caused by the piston group wearing out when the compressor simply cannot create the necessary pressure.
- 🔊 Loud knocking or clanging: Indicates the destruction of bearings or valves inside the mechanism.
- 🔥 Strong heating of the housing: May indicate overload, insufficient oil or problems with ventilation.
- ❄️ Lack of cold: When the motor is running, this is often a sign of a freon leak, rather than a breakdown of the compressor itself.
- ⚡ Protection activation: An instantaneous power outage indicates a short circuit in windings.
Diagnostics should begin by checking the voltage in the network and the state of the starting relay. If everything is in order with them, and the motor does not start or makes unnatural sounds, there is likely a defect in the motor-compressor itself motor-compressor.
☑️ Primary diagnostics of the refrigerator
Operation rules to extend service life
In order for the compressor to serve as long as possible, you must follow a number of simple operating rules. First of all, this concerns the installation of a refrigerator. The distance to the wall should be at least 5-10 cm to ensure normal air circulation around the condenser.
It is also important to avoid frequent defrosting by “forcible” means, for example, using a hairdryer or hot water. Sudden temperature changes create unnecessary stress on the system. It is not recommended to load a large amount of warm food into the chamber at once.
A critical factor in durability is the stability of the voltage in the electrical network: voltage surges can instantly disable the electronic control or motor windings, so the use of a surge protector or stabilizer is highly desirable in areas with unstable electricity supply.Compliance with temperature conditions also plays a role. Setting the regulator to maximum cold (“Max”) forces the compressor to work almost without interruption, which accelerates the wear of rubbing parts.
Frequently asked questions (FAQ)
Why does the refrigerator hum loudly immediately after turning on?
Humming in the first minutes of operation is normal. At this point, the compressor operates at full power to cool the chambers after being idle or loading products. If the noise does not change throughout the entire cycle or is accompanied by knocking, diagnostics is required.
Is it possible to replace a conventional compressor with an inverter one?
Theoretically this is possible, but in practice it requires a complete replacement of the control system and often the circuit itself. The electronics of a conventional refrigerator cannot control the inverter motor. Such a replacement is not economically feasible and is equivalent to the purchase of new equipment.
How long should the compressor operate normally?
Under normal conditions, the compressor operates about 30-40% of the total time (switching ratio). That is, he can work for 10 minutes and rest for 20 minutes. If it turns on more often or works without stopping, check the tightness of the door and the condition of the seal.
Is it dangerous to touch a running compressor?
It is not recommended to touch a running compressor. During operation, it heats up to 60-90 degrees Celsius, which can cause burns. In addition, voltage may be present on the casing in the event of an insulation breakdown, although modern models have reliable grounding.