When household appliances stop performing their functions or make strange sounds, owners often wonder how exactly their equipment works. The most common misconception is looking for the “motor” in the design of a refrigerator. In fact, in the classical sense, like in a washing machine or car, there is no motor that rotates the drum or wheels.
The correct technical name for this unit is compressor. It is he who is responsible for circulating the refrigerant through the pipe system, creating the necessary pressure to cool the chambers. Understanding that you are dealing with a compressor, and not just an engine, will help you more accurately formulate the problem when calling for service or searching for spare parts on the Internet.
In this article we will look in detail at why there is confusion in terms, what types of these units exist and how to determine that this particular unit has failed. Knowing the structure of your refrigerator will allow you to avoid unnecessary expenses on diagnostics and will help you quickly bring the equipment back to life.
Why a compressor is called an engine
The term “engine” in the context of refrigeration technology has taken root among people not by chance. Visually and functionally, a compressor truly resembles an electric motor: it hums, vibrates, and consumes electrical energy to create mechanical work. However, technically this is a more complex unit, combining electric motor and the compressor part itself (pump).
The electric motor drives the pistons or spiral, which compress the gaseous refrigerant. Therefore, when they say “the engine burned out,” most often they mean the failure of the electric motor winding inside the sealed compressor casing. It is important to distinguish between these concepts, since repairs can concern both the electrical and mechanical parts.
Modern models, especially with the system No Frost, may have additional fans that have their own small motors. But the main power unit always remains the compressor, located in the lower rear part of the case.
- 🔧 The compressor is the heart of the refrigerator, creating pressure.
- ⚡ The electric motor is the internal part that rotates the compression mechanism.
- ❄️ Refrigerant is the substance that transfers heat from the chambers outside.
Main types of compressors in refrigerators
Technology does not stand still, and over the decades of evolution of household appliances, engineers have developed several types of compressors. Each of them has its own design features, noise level and energy efficiency. Understanding the differences will help you choose the right model when purchasing or correctly estimate the cost of repairs.
The most common for many years were piston units. They work on the principle of a reciprocating piston that compresses gas. Such devices are reliable, but can be noisy and consume more electricity due to constant cycles of switching on and off at full power.
In recent years, inverter models have become increasingly popular. They do not turn off completely, but only reduce engine speed, maintaining the set temperature. This ensures quiet operation and significant savings in resources, although the initial cost of such equipment is higher.
There are also linear compressors, which are a type of piston compressor, but lack a crank mechanism, which reduces friction and noise. In industrial or very old models you can find rotary options, but in everyday life they are rare.
The principle of operation of a refrigeration unit
To understand the importance of the compressor, you need to briefly consider the refrigeration cycle. The whole process is based on the physical property of substances to absorb heat during evaporation and release it during condensation. The compressor here acts as a pump that forces the refrigerant to move in a closed circuit.
Freon gas leaves the evaporator (inside the chambers) and enters the compressor. Here it is compressed, as a result of which its temperature and pressure increase sharply. The hot gas then enters the condenser (grid at the back or sides of the housing), where it cools and turns into liquid.
Passing through the capillary tube and filter drier, the refrigerant pressure drops and it enters the evaporator. There it boils again, turning into gas and actively taking heat from the food. After this, the cycle repeats. Malfunction of any link in this chain leads to loss of cold.
| Component | Function | Location |
|---|---|---|
| Compressor | Gas compression and circulation | Rear, bottom |
| Condenser | Cooling and condensation | Rear grille |
| Evaporator | Evaporation and heat intake | Inside the chamber |
| Filter drier | Cleaning from moisture and debris | Before the capillary |
What is refrigerant?
Refrigerant (freon) - this is the working substance that circulates in the system. Modern refrigerators most often use safe gases R600a (isobutane) or R134a. They are colorless and odorless, but if they leak, they require professional refilling.
Signs of a compressor malfunction
You can determine that the refrigerator “engine” is faulty by a number of characteristic signs. Often a breakdown does not occur instantly, and the equipment gives signals long before complete failure. Attention to detail will help prevent food spoilage.
One of the most obvious symptoms is constant operation. If the refrigerator hums continuously and does not turn off while trying to get up to temperature, this may indicate a loss of compressor performance or a freon leak. In normal mode, the equipment should turn on and off cyclically.
It is also worth paying attention to the temperature of the case. If the compressor itself (the metal “tank” at the back) is hot to such an extent that it is impossible to touch it, or, conversely, remains absolutely cold when the engine is running, this is an alarming sign. In the first case, overheating of the windings is possible, in the second - a broken circuit or jamming of the mechanism.
⚠️ Attention: If you smell burning or see sparking in the area of the start relay (plastic box on the side of the compressor), immediately disconnect the device from the network. Operation in this condition may result in a fire.
Another sign is a loud knocking or clanging noise when starting up. This often indicates mechanical wear of internal parts, broken bearings or problems with fastening shock absorbers.
☑️ Compressor diagnostics
Is it possible to repair the compressor yourself
Question of repairing the compressor at home is one of the most controversial. Theoretically, anyone with minimal skills and a screwdriver can replace the start relay or capacitor. These parts are located outside the sealed casing and are inexpensive.
However, if the problem lies inside the metal flask - depressurization, burning of the windings or jamming of the piston group - independent repair is practically impossible and impractical. To open the casing, weld the tubes and evacuate the system, specialized equipment and skills are required.
Moreover, replacing a compressor requires working with refrigerant, which implies the presence of a license and a special tool for pumping out old gas and filling new one. Attempts to “just replace the motor” without evacuation of the system will lead to instant failure of the new part.
Therefore, if diagnostics showed a malfunction of the unit itself, the most reasonable solution would be to call a technician to professionally replace the assembly. This guarantees the tightness of the system and the correct dosage of oil and freon.
Increasing the service life of the refrigerator engine
In order for the compressor of your refrigerator to serve the 10-15 years stated by the manufacturer, you must follow simple operating rules. The main enemy of technology is overheating. The compressor needs to effectively dissipate heat to the environment.
Ensure free air circulation around the back wall and sides of the device. Do not move the refrigerator close to the wall, leave a gap of at least 5-10 cm. Regularly, at least once a year, clean the rear grille (condenser) from dust and pet hair using a vacuum cleaner or soft brush.
It is also important not to overload the chambers with food immediately after defrosting or purchasing. A sharp increase in temperature inside forces the compressor to work at its maximum capacity for a long time, which reduces the life of its parts.
- 🧹 Regularly wipe the dust from the rear grille.
- 🌡️ Do not place hot food inside the chambers.
- 🚪 Check the density fit of the door seals.
Why does the refrigerator hum loudly after installation?
A loud hum in the first hours of operation is often associated with improper installation. Check if the refrigerator is level. If the feet are not adjusted, vibration from the compressor is transmitted to the cabinet and floor, increasing the noise. Also make sure that the equipment does not touch the wall or furniture.
Can a power surge burn the engine?
Yes, modern compressors are sensitive to voltage changes in the network. The surge can damage the start relay or pierce the insulation of the electric motor windings. To protect expensive equipment, it is recommended to use surge protectors or voltage stabilizers.
What to do if the compressor turns on for 2 seconds and turns off?
This is a classic symptom of a faulty start relay or a jammed compressor. The relay tries to start the motor, the current increases sharply, the protection is triggered, and the system turns off. Diagnostics of the electrical part is required.