When the refrigerator starts hums, vibrates or stops freezing, the owner usually says that “the motor has burned out.” This everyday name has taken root so much that many do not even know what the technical correct name for this unit is. In fact, what we used to call a motor is compressor the heart of the entire refrigeration system. It is he who is responsible for the circulation of the refrigerant, creating the necessary pressure drops for cooling the chambers.
Understanding that what is the name of the motor in the refrigeratoris only the first step towards proper operation. The type of supercharger installed determines the noise level, energy consumption and durability of the device. Modern models use complex engineering solutions that are radically different from old Soviet units.
In this article we will analyze in detail the design of the compressor, consider the different types of motors and find out why some operate silently, while others emit noticeable vibration. Knowledge of these details will help you better understand the needs of your equipment and notice signs of malfunction in time.
The principle of operation of a refrigeration engine
The main task of the compressor is to compress and move the refrigerant through a closed circuit of the system. Sealed case hides inside the electric motor and the compressor part itself, operating in an oil environment. When you turn on the refrigerator, the electric current starts the rotor, which sets the pistons in motion or rotates the spiral, depending on the design.
The cooling process is based on the physical property of gases: when compressed, they heat up, and when they expand sharply, they cool down. The compressor compresses gaseous freon, increasing its pressure and temperature, after which the hot gas is sent to the condenser (radiator on the rear wall), where it releases heat into the room. Technical fluid cools and turns into a liquid state, after which it passes through a capillary tube and choke, where it expands sharply and cools, taking heat from the refrigerator chambers.
⚠️ Attention: Never try to open the sealed compressor casing yourself. There may be gas under pressure inside, and the oil used for lubrication is often flammable and toxic when heated.
The cycle is repeated until the temperature sensors record that the specified parameters have been reached. It is important to understand that motor-compressor is not just a pump, but a mechanism that requires stable voltage and proper heat transfer. Overheating of the windings or jamming of mechanical parts are the most common causes of failure of this unit.
The main types of compressors in refrigerators
When asked what the motor in a refrigerator is called, the answer “compressor” is correct, but this is not enough. There are several fundamentally different types of these devices, each of which has its own advantages and disadvantages. The choice of technology directly affects the price of the appliance and the comfort of its use.
The most common are piston compressors. They work on the principle of a reciprocating piston that compresses gas. Such engines are reliable, maintainable and relatively cheap to produce. However, their operation is often accompanied by characteristic sound and vibration, since crank mechanism creates inertial loads with each switching cycle.
Rotor and inverter models are considered more modern and quiet. In rotary engines, compression occurs due to rotation of the rotor, which eliminates translational movements and reduces the noise level. Inverter compressors represent the pinnacle of evolution: they do not turn off completely, but only change the shaft speed, maintaining a constant temperature. This allows you to save energy and avoid temperature changes.
We should especially mention linear compressors, which are often found in premium technology. They use a linear actuator to move the piston, which minimizes friction and wear on parts. Such devices are highly energy efficient and have a long service life, although their repair may be more expensive due to the complexity of the electronics.
Compressor characteristics comparison table
To better understand the differences, consider a summary table comparing the main parameters of different types of engines. This will help you understand what to look for when choosing new equipment or diagnosing old equipment.
| Compressor type | Noise level | Energy consumption | Service life | Repair cost |
|---|---|---|---|---|
| Piston | High (40-45 dB) | Medium/High | 8-10 years | Low |
| Rotary | Average (35-40 dB) | Average | 10-12 years | Average |
| Inverter | Low (up to 30 dB) | Low (class A++) | 15+ years | High |
| Linear | Low/Medium | Low | 10-15 years | High |
The table shows that modern technologies win in all respects, except, perhaps, the initial cost and the price of spare parts. However, if you recalculate energy costs over 10 years, inverter motor pays off its high price. It is important to note that these characteristics may vary depending on the manufacturer and the specific model of the refrigerator.
⚠️ Attention: Specifications and availability of spare parts may vary depending on the year of manufacture and region of sale. Before purchasing an expensive compressor, check the model with the manufacturer's catalogs or contact an authorized service center.
Causes of noise and vibration during motor operation
If your “motor” begins to make noise louder than usual, this is a signal that diagnostics are needed. Noise can be caused by both external factors and internal breakdowns. Most often, vibration is transmitted to the refrigerator body if it stands unevenly or touches the wall.
Internal causes of noise often lie in wear of bearings or valves. When bearing assembly exhausts its resource, a metallic hum or knock appears. Also, the source of sound can be the piston itself if it begins to touch the cylinder walls due to the development or entry of foreign objects into the system.
- 🔊 Humming: Often indicates problems with the electrical part of the motor or overload during startup.
- 🔨 Knock: Indicates mechanical wear of the piston group or loosening of the compressor fastenings to the frame.
- 🌪️ Whistling: Can occur due to a refrigerant leak or problems with the circulation of freon in system.
Sometimes the noise is caused not by the compressor itself, but by the fan (if the No Frost model has one). The blades may touch ice or foreign objects. In such cases, it is necessary to defrost the refrigerator and check the free movement of the blades. If the noise remains after defrosting, the problem is probably in the motor compressor. Is it possible to lubricate the compressor if it is noisy? motor-compressor.
Is it possible to lubricate a compressor if it is noisy?
No, it is not possible. The compressor is a sealed system. An attempt to drill a hole for lubrication will lead to depressurization, moisture and air entry, which will completely damage the unit. The lubrication inside changes only with a complete replacement of the unit or professional repair with re-soldering.
Diagnostics of compressor faults
Understanding how a working motor behaves will help you quickly identify anomalies. In normal operation, the compressor turns on, runs for a certain time (duty cycle), then turns off until the next temperature increase. If this cycle is broken, intervention is required.
One of the common problems is the situation when the engine hums but does not start, or starts for a couple of seconds and stalls again. This often indicates a malfunction start relay or a break in the motor windings. A relay is a small plastic block that fits onto the compressor contacts. Replacing it is one of the simplest and cheapest repair procedures.
If the compressor runs continuously without turning off, this may indicate a loss of system tightness (freon leakage) or failure of the thermostat. In the first case, the motor tries to catch up with the temperature, but cannot due to a lack of refrigerant, which leads to its overheating and eventual combustion.
☑️ Primary diagnostics of the motor
It is also worth paying attention to the temperature of the housing. The normal operating temperature of a working compressor housing is considered to be in the range from 50 to 90 degrees Celsius. If the metal is heated to such an extent that it is impossible to touch it, or, conversely, remains cold when the engine is running, these are signs of a serious malfunction.
Repair or replacement: what to choose?
When a “motor” breakdown is diagnosed, the owner is faced with the question: repair or replace? In most cases, especially with modern sealed models, repairing the compressor itself is not economically feasible. The cost of resoldering, vacuuming and refilling is often comparable to the purchase of a new unit.
Replacing a compressor is a complex procedure that requires special equipment: a vacuum pump, a pressure gauge station and a burner. The technician must remove the old unit, solder the new one, create a vacuum in the system to remove moisture, and charge the exact amount of refrigerant. It is almost impossible to carry out these operations on your own without experience and tools.
- 🛠️ Replacement of the relay: Cheap and quick, often solves the problem with starting.
- 🔄 Complete replacement of the compressor: Expensive, but gives a second life to the refrigerator.
- ❌ Repair of windings: Cannot be done at home, requires motor rewinding in specialized workshops.
If your refrigerator is more than 10-12 years old, sometimes it is more profitable to purchase new equipment than to invest in expensive repairs of an old compressor, especially if the model is energy-intensive. However, for premium models, replacement motor compressor is often the only reasonable solution that extends the life of an expensive appliance.
⚠️ Attention: When replacing a compressor, be sure to use the refrigerant of the same brand and in the same volume as indicated on the refrigerator's factory tag. Using the wrong freon can lead to destruction of the compressor or a fire hazard.
How to extend the life of a refrigerator motor
The durability of the compressor directly depends on the operating conditions. In order motor in the refrigerator to serve as long as possible, it is necessary to provide it with a comfortable temperature regime and a stable power supply. Overheating is the main enemy of any electric motors.
Regularly clean the condenser (grid at the back or bottom of the refrigerator) from dust and animal hair. A radiator clogged with dust cannot effectively transfer heat, causing the compressor to work under increased load and overheat. This leads to accelerated wear of the oil and mechanical parts.
It is also important to avoid frequent power surges. Electrical surges can damage the motor windings or control electronics. Using a surge protector or voltage stabilizer will be an excellent investment in the safety of equipment, especially in homes with old wiring.
Do not load a large amount of warm food into the refrigerator at once. A sharp increase in temperature inside the chambers will force the compressor to work at its limit for a long time, which reduces its service life. Let the food cool to room temperature before putting it on the shelf.
Is it possible to replace the compressor yourself without experience?
Theoretically, it is possible if you have the skills to solder copper pipes, a vacuum pump and pressure gauges. However, in practice this is extremely difficult. Unprofessional soldering can lead to freon leakage, and a lack of vacuum during refueling can lead to the formation of ice plugs and rapid failure of the new compressor. It is recommended to entrust this work to professionals.
Why is the new refrigerator louder than the old one?
This may be due to the type of compressor. Some modern models use more powerful motors for faster cooling, or the design of the case dampens vibration less well. Also, the noise level depends on the quality of the refrigerant and the system settings. If the noise is accompanied by knocking or squealing, this is a sign of a defect.
How long does the motor in a refrigerator last on average?
The average service life of a modern compressor is from 10 to 15 years with proper operation. Inverter models can operate for up to 20 years or more. Old Soviet refrigerators sometimes worked for 30+ years, but consumed significantly more energy and required periodic replacement of seals and oil.
What to do if the compressor gets very hot?
First of all, move the refrigerator away from the wall and check the cleanliness of the condenser. Make sure the room is not too hot. If the body is red-hot or smells of burnt insulation, immediately disconnect the device from the network and call a technician, as there is a high risk of fire.
Does the amount of freon affect the operation of the motor?
Yes, directly. A lack of freon causes the compressor to work continuously, trying to gain temperature, which leads to overheating. Excess freon creates too high pressure in the system, which also overloads the motor and can lead to mechanical destruction of valves or pistons.