A sudden stop in the refrigerator is always stressful for the owners, because food supplies are at risk. The first thing owners often blame is a lack of electricity or a network failure, but if the outlet is working properly and there is silence inside, most likely the problem lies in the heart of the unit - the compressor. It is this unit that is responsible for the circulation of the refrigerant, and its failure paralyzes the entire cooling system.
Before calling a technician or running to the store for new equipment, it is worth conducting an initial diagnosis. Checking the refrigerator motor is a process that, if you have basic skills and a minimum set of tools, can be performed independently. This will allow you to save a significant amount on diagnostics and understand whether the game is worth the candle, or whether repair is no longer practical.
In this article we will analyze in detail the algorithm of actions that will help identify the malfunction. We will consider external signs of failure, methods of instrumental measurement of winding resistance and testing of the starting relay. Understanding these processes will give you a clear idea of the condition of your device Indesit, Atlant or any other brand.
Primary visual diagnostics and sound analysis
Any professional diagnostics begin long before connecting measuring instruments. Careful observation of the behavior of the refrigerator can provide up to 50% of the necessary information. If the unit hums but does not start, or makes clicking noises, this already indicates a specific range of problems.
Pay attention to the nature of the sound. A uniform hum, turning into silence, may indicate the activation of a thermal protection relay. If you hear a loud click, followed by a hum for a couple of seconds and then a stop click again, this is a classic symptom of a “wedge” of the motor or a malfunction of the starting system.
⚠️ Attention: If you smell burnt insulation or see sparking in the compressor area, immediately unplug the device. Further attempts to start may result in a fire.
It is also important to check the temperature of the compressor housing itself. If it is hot, almost burns your hand, but the refrigerator does not cool, this may indicate an interturn short circuit or operation in the “dry running” mode due to a freon leak. A cold motor with the light turned on inside the chamber indicates that the electrical circuit is broken and the current simply does not reach the windings.
Checking the voltage in the supply network
Sometimes the reason is trivial, and you should not go inside the unit until external factors have been ruled out. Electrical network in our homes is often far from ideal, and power surges can block the start of powerful consumers. First, make sure that the problem is in the refrigerator and not in the outlet.
Use a multimeter or voltmeter to measure the voltage. Connect the appliance to the outlet where the refrigerator is plugged in. A value in the range of 220–230 Volts is considered normal. If the readings fluctuate greatly or the voltage is below 190 Volts, the motor may not start due to protection or lack of power to start.
It is also worth checking the integrity of the power cord and plug. Visually inspect them for melting, cracks or kinks. Owners often forget that an extension cord or surge protector may not withstand the starting currents of the compressor, creating a false impression of equipment failure.
Removing the casing and accessing the compressor
If external checks do not reveal any problems, you will have to take more decisive action. To access the electrical part of the motor, you must remove the protective cover located at the lower rear of the refrigerator. It is usually secured with latches or screws.
Before starting work, be sure to disconnect the refrigerator from the power supply! Unplug the plug from the socket. This critical for your safetysince you will be working with conductive elements under voltage (after switching on) or accumulated charge. Let the unit stand for 10-15 minutes.
Removing the cover, you will see the compressor - a black metal “pan”. Three wires go to it and go into a plastic box - these are the starting and thermal relay. Carefully remove this box. On older models it can simply be removed by hand, on new ones it can be fixed with a bracket.
Inspect the contacts for oxidation or carbon deposits. If you see black burn marks on the terminals or inside the relay, this is a sure sign that there was a poor connection somewhere causing heat and sparking. In such cases, it is often necessary to replace not only the relay, but also to clean the contact group.
Diagnostics of the starting and thermal relay
A frequent reason that the motor does not startis the failure of the starting relay. This small unit is responsible for sending an impulse to the starting winding to spin the motor shaft. The thermal relay, in turn, protects the motor from overheating by opening the circuit at critical temperatures.
The relay can be checked visually and using a continuity test. Shake the relay near your ear: if a ringing sound is heard inside, it means that the ceramic core or contacts have broken and the part must be replaced. For electrical testing, remove the relay and ring the contacts with a multimeter in resistance measurement mode.
- 🔌 Thermal relay contacts: should ring short (resistance close to zero) in a cold state. If the circuit is broken, the relay has burned out.
- ⚡ Starting coil: should have low resistance. Check the contacts going to the motor windings.
- 🌡️ Temperature test: The thermal relay can be gently heated (for example, with a hairdryer), and it should click, breaking the circuit. After cooling, close it again.
If the relay is working properly, but the motor is silent, the problem is deeper. However, statistics say that in 40% of cases of a “non-working” refrigerator, it is a stuck or burnt-out relay that is to blame, and not the expensive compressor itself. Replacing this part is inexpensive and often solves the problem.
Why does the relay burn out?
A common reason for a relay burning out is poor-quality voltage in the network or rare but powerful surges. Also, the relay may not withstand frequent switching on and off of the refrigerator if the tightness of the circuit is broken and the motor runs without interruption.
Testing the motor windings with a multimeter
The most reliable way to understand the condition of the electric motor is to measure the resistance of its windings. To do this, you will need a multimeter switched to resistance measurement mode (Ohms) to a limit of 2 kOhms. There are usually three terminals on the compressor housing, often identified by letters or wire colors.
Remove the jumpers and connect the multimeter leads to the pairs of terminals. You need to get three values: the resistance between the working and starting windings, the resistance of the working winding and the resistance of the starting winding. The sum of the two smaller resistances should be equal to the larger one (resistance between the extreme terminals).
Here are the approximate values for a working motor:
| Pair of contacts | Normal resistance (Ohm) | What does deviation mean |
|---|---|---|
| Working - Starting | Sum of the other two | Open circuit or short circuit |
| Working - Housing | Infinity (∞) | Breakdown to the housing (dangerous!) |
| Starting - Housing | Infinity (∞) | Insulation breakdown |
If the multimeter shows one (infinity) where there should be resistance, This means there is a break in the winding. If it shows zero, there is a short circuit. In both cases, the compressor is considered faulty and requires replacement. Also critical breakdown to the body: if the device shows any resistance between any terminal and the copper tube or body, operating such a refrigerator is deadly.
☑️ Dialing procedure
Assessment of the mechanical condition and compressor wedge
It happens that the electrical part is completely intact: the windings ring, the relay is working, there is voltage, but the motor does not start. In this case, there is a high probability of mechanical failure, the so-called “wedge”. The piston group inside the sealed flask could have jammed due to wear-out, moisture entering the system, or loss of oil.
It is more difficult to diagnose the wedge. If, when turned on, the motor hums and twitches, but the shaft does not turn, and after a few seconds the thermal protection clicks, this is it. There is a method of “wedging” by applying increased voltage, but it requires special equipment (transformer) and is dangerous. At home, it is better not to use this method without experience.
⚠️ Attention: Attempts to wedge the compressor with a hammer or strong vibration often lead to the final destruction of the internal mechanisms. If the motor is jammed, in 90% of cases it is easier to replace it with a new one.
It is also worth checking the heat removal system. If the condenser (grid at the back) is clogged with dust or pushed close to the wall, the motor may overheat and go into protection. Make sure that there is a gap around the refrigerator for air circulation.
When it is necessary to replace the compressor
If the diagnostics showed a break or short circuit in the windings, a breakdown in the housing or a deep mechanical wedge, the only solution is to replace the unit. This is a complex procedure that requires a vacuum pump, a pressure gauge station and skills in soldering copper tubes.
Independent replacement of the compressor without the appropriate equipment is impossible, since the system must be evacuated and charged with freon strictly by weight. An attempt to simply resolder the tubes and start the motor will lead to previous failure due to the presence of moisture and air in the circuit.
In this case, it is more rational to call a specialist who will bring a new compressor and perform the entire cycle of work. The cost of such repairs consists of the price of a new unit, refrigerant and the work of a technician. For old refrigerators, it is sometimes cheaper to buy new equipment than to repair old equipment.
Frequently asked questions (FAQ)
Can a refrigerator motor burn out due to a voltage surge?
Yes, voltage surges are one of the main reasons for the failure of motor windings. A sudden surge can pierce the insulation, causing a short circuit. For protection, it is recommended to use voltage stabilizers or voltage control relays.
Why is the motor hot, but the refrigerator does not freeze?
This may indicate a freon leak. The compressor is idling, trying to pump up pressure, but there is not enough refrigerant in the system. Also, the cause may be a clogged capillary tube or inefficient operation of the compressor itself (valve wear).
How long does a compressor last in a refrigerator on average?
The average service life of a modern compressor is 10–15 years. However, under favorable conditions (stable voltage, clean capacitor, absence of frequent defrosting), it can last 20 years. Chinese budget models often last less - about 7-10 years.
Is it possible to replace the compressor with an analogue from another brand?
Yes, you can, but you need to observe a number of parameters: power, refrigerant (R134a, R600a), oil type and overall dimensions of the seat. It is best to select an analogue according to the correspondence table or consult with a specialist so as not to disrupt the operation of the system.