When you hear a humming sound coming from the kitchen, or, conversely, notice that the chamber has become too warm, the first thing that comes to mind is problems with the “heart” of the unit. Refrigerator motor, which is technically more correctly called a compressor, is the main unit that circulates the refrigerant. It is on its proper operation that it depends whether your products will be fresh or spoiled.
Many users are confused about the terms, calling this unit just a motor, but inside the sealed casing hides a complex system of pistons, valves and electrical windings. Understanding what is a motor in a refrigerator and how it functions will help you diagnose the problem faster and avoid unnecessary expenses on calling a technician for minor repairs. In this article, we will analyze the structure of the unit, the types of modern compressors and signs of wear.
If you notice that the device has started to work louder than usual or has stopped starting altogether, there is no need to panic. Fault diagnosis requires composure and basic knowledge about the principles of operation of the equipment. We will look at why the device may overheat, what clicking noises mean when starting up, and when the unit really needs to be replaced.
Operation principle and design of the compressor
The main task of this mechanism is to compress and pump refrigerant through a closed system circuit cooling. Electric motor, located inside a sealed housing, drives a piston or other group that creates the necessary pressure. Without this pressure, freon would not be able to effectively transfer heat in the condenser and take it from the evaporator.
Structurally, the unit is a sealed metal casing, inside which the compressor itself and the electric motor are suspended on springs. Such a suspension is necessary vibration dampening, since during operation the pistons make hundreds of reciprocating movements per minute. The oil located in the lower part of the casing lubricates the rubbing parts and is involved in heat removal.
⚠️ Attention: Opening the sealed compressor casing at home is strictly prohibited. This will not only disrupt the factory balancing, but can also lead to oil release and moisture entering the system, which will permanently damage the refrigerator.
The operating cycle begins by applying voltage to the start relay. At this moment starting winding creates the magnetic field necessary to rotate the rotor. As soon as the engine reaches the required speed, the relay turns off the starting winding, and the motor continues to operate on the main one. Violation of this process is a common reason why the device hums but does not start.
Why is the compressor hot?
During operation, the motor heats up to 60-90 degrees Celsius. This is the normal operating temperature required to evaporate any oil that has entered the system and maintain lubricant viscosity. However, if the casing becomes hot to the point where it is impossible to touch it, this is a signal of overload or malfunction of the thermostat.
Main types of refrigeration motors
Technologies do not stand still, and today you can find various types of drives on the market. Standard compressor works on the principle “on-off”: it reaches the desired temperature and turns off until it rises above the specified threshold. This is a time-tested, but not the most economical scheme.
A more modern solution is inverter motor. It does not turn off completely, but only reduces the speed, maintaining the temperature in a narrow range. This allows you to significantly save energy and reduce noise levels, since there are no constant cycles of starting and stopping under full load.
- 🔹 Piston: classic version with one or two pistons, reliable and maintainable, but noisy.
- 🔹 Inverter: quiet, durable, smoothly regulate power, but sensitive to power surges in the network.
- 🔹 Linear: work without a crank mechanism, which reduces the number of friction points and increases energy efficiency.
When choosing equipment, it is worth considering which inverter technology requires a more stable voltage. If your home experiences frequent power outages, it is recommended to use a stabilizer. Conventional motors in this regard are more “omnivorous” and can more easily withstand external influences.
Symptoms of a refrigerator motor malfunction
You can determine what refrigerator motor requires attention based on a number of indirect signs. The most obvious of them is a change in the sound of the unit. If a previously quiet hum has been replaced by a metallic clang, rumble or piercing whistle, this is a sure sign of mechanical wear of internal parts.
Another alarming signal is the operating mode. A normal cycle involves the device operating for about 20-30 minutes, followed by a pause. If compressor it buzzes without a break for hours or, conversely, starts for a couple of seconds and clicks, trying to start again, then the system has failed. In the first case, there may be a freon leak or wear of the piston group, in the second - problems with the start relay or a wedge of the mechanism.
It is also worth paying attention to the temperature of the housing. Excessive heating, accompanied by the smell of burning or scorched wiring, requires immediate disconnection of the device from the network. Overheating of the windings can lead to a short circuit and fire.
- 🔸 The refrigerator stopped freezing, but the motor is silent.
- 🔸 The unit operates continuously, without going into rest mode.
- 🔸 Extraneous knocks are heard, the vibration of the body has increased.
- 🔸 The motor starts for a few seconds and stalls with a characteristic click.
⚠️ Attention: If you smell burning insulation or see sparking in the rear wall area, immediately remove the plug from the outlet. Operation of such a device is life-threatening.
Diagnostics: how to check performance
Before making a decision about replacement, it is necessary to carry out initial diagnostics. Often the problem lies not in the motor itself, but in the accompanying elements. Checking the starting relay is the first place to start. It is this small block that is responsible for providing an impulse to start the engine.
For a deeper check, you will need a multimeter. With its help, you can ring the motor windings for breaks or short circuits. The normal winding resistance depends on the model, but usually ranges from 10 to 30 ohms for starting and slightly less for operating. If the device shows infinity or zero - the motor is faulty.
It is also important to check the feed-through contacts. They should “ring” with the windings, but should not have contact with the body. A breakdown on the housing is a death sentence for the motor, since it is impossible to restore tightness and insulation in domestic conditions.
☑️ Primary diagnostics of the motor
Table of faults and solution methods
For the convenience of systematizing the problems faced by owners, we will compile a summary table. It will help you navigate the nature of the breakdown and the approximate cost of restoration.
| Symptom | Probable cause | Solution method | Difficulty |
|---|---|---|---|
| The engine hums, but does not start | The starting relay is faulty or the piston is jammed | Replacing the relay or motor | Average |
| Continuous operation without shutting down | Freon leakage or compression wear | Refilling the system or replacing the unit | High |
| Strong vibration and noise | Bearings are broken or springs are weakened | Replacing the motor | High |
| Shutdown after 10-20 seconds | Thermal protection relay is triggered | Checking the windings and replacing the motor | High |
It is worth noting that replacement of the compressor is a complex technological process. It requires not only the installation of a new unit, but also evacuation of the system, charging the exact amount of refrigerant and oil. This can only be done efficiently using special equipment.
Replacing the motor: is it worth doing it yourself?
Theoretically, it is possible to replace refrigerator motor with your own hands if you have the skills to work with tools and an understanding of the principles of operation of refrigeration systems. However, in practice this presents a number of difficulties. The main one is the need to work with refrigerant, which requires disposal, and the use of welding to connect copper tubes.
The process begins with dismantling the old unit. To do this, you need to bleed off the remaining gas (if any), carefully cut off the copper tubes and disconnect the electrical wires. The new motor must be selected strictly according to the model or have compatible characteristics in terms of power and refrigerant. Universal solutions there is practically no such thing here.
After installing a new unit, it is critical to create a vacuum in the system. Remaining air or moisture will cause ice blockages and acids to form, which will destroy the new compressor within a few months. Therefore, if you do not have a vacuum pump and a pressure gauge station, replacing the motor yourself is not recommended.
⚠️ Attention: Technical characteristics and requirements for refrigerants may vary depending on environmental standards. Always check the type of oil and freon indicated on the nameplate of your refrigerator with the data of the new compressor.
In addition, modern electronically controlled refrigerators may require re-flashing the board after replacing the hardware. Without special software and adapters, a new motor may simply not work or work in emergency mode.
Prevention and extension of service life
To refrigerator motor served for as long as possible, you must follow simple operating rules. First of all, this is to ensure adequate ventilation. The back wall of the device should be at least 10-15 cm from the wall so that heat is effectively dissipated. Overheating is the main enemy of any electronics and mechanics.
Regular defrosting (for No Frost models - preventative washing) is also important. Ice buildup on the evaporator causes the compressor to work longer and harder to maintain the set temperature. This leads to accelerated wear of the piston group and overheating of the windings.
- ✅ Do not place hot products in the chamber - this creates an extra load.
- ✅ Monitor the integrity of the door seal - the cold should not escape.
- ✅ Use a voltage stabilizer if there is a power supply jumps.
- ✅ Periodically clean the condenser (grid at the back) from dust.
Following these recommendations will significantly increase the service life compressor and avoid costly repairs. Remember that prevention is always cheaper than replacing the main components.
How long does a refrigerator motor last on average?
The average service life of a modern compressor is from 10 to 15 years. Inverter models can operate for up to 20 years or more due to the absence of constant starting loads. However, the real figure greatly depends on the operating conditions, the quality of the voltage in the network and the frequency of opening the doors.
Why can a new motor make more noise than the old one?
New compressors, especially piston type ones, can work louder due to the lack of “ground-in” parts. Also, the noise level depends on the quality of installation: if the tubes vibrate against the body or cabinet wall, the sound will increase. Usually, after a week of operation, the noise should decrease.
Is it possible to use a used compressor for replacement?
Using a used motor is a lottery. The resource of such a node is unknown, and it may fail in a month. In addition, oil or moisture may have entered the system of the old compressor. Savings in this case are questionable and often lead to repeated repairs.
What to do if the motor hums, but the refrigerator does not freeze?
Most likely, there has been a loss of compression (wear of the piston group) or a refrigerant leak. The motor runs idle without creating pressure. You need to call a technician to diagnose and, probably, replace the compressor and refill the system.