The situation when the refrigerator Atlant stops freezing, but at the same time makes a hum or, conversely, is silent, often frightens the owners. First of all, in such cases, suspicion falls on the heart of the unit - compressor. It is this unit that is responsible for the circulation of refrigerant through the system, and its failure leads to a complete loss of cold in the chambers.
Before calling a technician or running to the store for a new spare part, it is necessary to conduct a thorough diagnosis. Often the problem lies not in the motor itself, but in the starting relay or thermostat, the replacement of which is much cheaper. In this article we will analyze the algorithm for checking the serviceability of the refrigerator compressor Atlant using available tools.
Please note that any work related to electricity and opening the case requires compliance with safety precautions. If you are not confident in your abilities, it is better to entrust the repair to professionals, since inept actions can lead to more serious damage or injuries.
Primary visual and acoustic diagnostics
You should start checking by simply observing the operation of the unit. Plug in the refrigerator and listen to the sounds it makes. A working compressor usually produces a smooth, monotonous hum, which periodically subsides when the set temperature is reached. If you hear clicks, a hum that ends abruptly, or complete silence, these are the first signals of a malfunction.
Carefully inspect the back wall of the refrigerator in the area of the motor. Pay attention to the condition of the start relay and wires. Soot, melted plastic or traces of soot on parts indicate overheating or a short circuit. It is also worth checking whether the compressor housing itself is heating up: if it is hot but there is no cold, the piston may have jammed or a thermal breakdown has occurred.
⚠️ Attention! If, when turned on, you hear a loud click, followed by a hum, and after a few seconds there is a second click and silence, this is the operation of a thermal protection relay. Do not try to turn on the refrigerator repeatedly, this may permanently damage the windings.
Often owners confuse a compressor failure with a malfunction of the No Frost system or a clogged capillary pipe. To rule out these options, check the operation of the fan (if there is one) and make sure that there is no ice coat on the evaporator blocking the airflow. A visual inspection helps to weed out up to 30% of false diagnoses.
Checking the starting relay and thermostat
Before “sinning” on the motor itself, it is necessary to exclude from the control circuit the elements that fail most often. In refrigerators Atlant the starting and protective relays are responsible for starting the engine. Their task is to apply an impulse to the starting winding and turn it off after gaining speed, as well as to protect the motor from overheating.
Remove the plastic casing from the compressor and carefully remove the relay. Visually assess its condition: there should be no traces of burning inside, and the contacts should be clean. Test the contacts with a multimeter in resistance test mode. If the device shows infinity or one where zero should be, the relay must be replaced.
- 🔌 Disconnect the wires from the relay and check the integrity of the cables suitable for it for fractures.
- 🌡️ Check the thermostat: when its contacts are closed in a warm state, the circuit should ring.
- ⚙️ Assess the condition of the capacitor (if it is installed in the start circuit) - swelling indicates its malfunction.
If the relay is working properly, but the compressor does not start, the problem may lie in the thermostat itself. If the thermostat breaks down, the start signal simply does not reach the engine. For a quick test, you can short the wires coming from the thermostat directly (briefly!) to see if the engine will start. However, this must be done carefully, controlling the temperature manually.
Why does the relay burn out?
A common reason for the start relay to fail is “fatigue” of the compressor itself. When the motor ages, starting currents increase, and the standard relay cannot withstand the load, burning out first. Therefore, replacing a relay on an old unit often gives only a temporary effect.
Instrumental check of windings with a multimeter
The most reliable way to find out the condition of an electric motor is to ring its windings. For this you will need a multimeter. Remove the start relay and protect the contacts from accidental short circuit. On the compressor body you will see three leads, usually arranged in a triangle.
Switch the multimeter to resistance measurement mode (2 kOhm). You need to call all three contacts in pairs. There must be a certain resistance between any two terminals. Typically it ranges from 10 to 30 Ohms for the working winding and slightly higher for the starting winding. If the device shows “1” or “OL” (open), it means that one of the windings has burned out.
Check diagram:1. Top contact - Bottom left: R1 (Start)
2. Upper contact - Lower right: R2 (Working)
3. Lower left - Lower right: R3 (Total)
It is also critically important to check the breakdown on the body. Switch the multimeter to dial mode (with sound) or high resistance measurement mode. Touch any terminal with one probe and touch the copper tube of the compressor or an unpainted part of the housing with the other. The device should not beep, and the arrow (or numbers) should not react. The presence of contact with the housing means that the compressor is “broken” and dangerous for use.
☑️ Diagnostic algorithm
Table of normal resistance values
For different models of refrigerators Atlant resistance values may vary slightly, but there are general ranges that are typical for serviceable motors. Compare your readings with the data in the table below.
| Winding type | Normal resistance (Ohm) | Fault symptom |
|---|---|---|
| Working winding | 10 - 25 Ohm | Open (∞) or short circuit (0 Ohm) |
| Start winding | 20 - 40 Ohm | Open (∞) or short circuit (0 Ohm) |
| Total (between the lower ones) | 30 - 65 Ohm | Inconsistency with the sum R1+R2 |
| Breakdown to the body | Infinity (∞) | Any value < 10 MOhm |
If your measurements are radically different from the table ones, for example, they show zero or infinity, then the electrical part of the compressor is faulty. Restoring a burnt winding at home is impossible - the entire assembly must be replaced.
It is worth noting that the resistance may “float” a little depending on the engine temperature. A cold motor will have less resistance than a hot one. Therefore, take measurements after the refrigerator has been unplugged for at least 2-3 hours.
Checking pressure and performance (discharge)
Electrical service does not guarantee that the compressor is capable of pumping freon. The motor may hum and consume current, but not create the necessary pressure in the system. This phenomenon is called "loss of productivity." To check, you will need a pressure gauge station.
The technicians connect the pressure gauge to the service fitting (usually it is located on the suction or discharge tube, if it was installed during a previous repair). When turned on, a working compressor should quickly gain pressure. For household models Atlant the norm is considered to be up to 6 atmospheres in a few seconds.
- 📉 If the pressure does not increase or increases very slowly, the piston rings or valves may be worn out.
- 💨 If the pressure breaks valve, the compressor will run idle without creating a pressure difference.
- 🔧 Check for “squeezing”: pinch the outlet of the discharge tube with your finger (be careful, you can get hurt!). A working motor should be noticeably restrained and not allow air to escape.
⚠️ Attention! The finger test is a rough method and does not provide accurate performance data. In addition, if the return flow valve is faulty, oil can be thrown out of the system, which will lead to contamination of the circuit.
A more professional method is to measure the current consumption with an ammeter (clamp meter). If the compressor hums but does not pump, the current will be below the rated current (indicated on the nameplate). If it is jammed, the current will be significantly higher than normal, which will trigger the protection.
Typical malfunctions and their symptoms
Understanding the symptoms helps to quickly determine the nature breakdowns. Compressors Atlant are reliable, but have their own “pain points”, especially after 10 years of operation. Let's consider the main failure scenarios.
The mechanism is jammed. The engine tries to start, a powerful beep is heard, the machine knocks out, or the wiring burns out. This happens when the oil thickens or mechanical wear of the rubbing pairs occurs. Sometimes “unclipping” by applying increased voltage helps, but this is a risky procedure.
Breakage of internal wiring. The compressor is silent, the relay clicks, but there is no start. The ringing shows infinity. This often happens due to vibration and chafing of the wires inside the case or burnout of the contacts on the block.
Interturn short circuit. The most insidious defect. The winding resistance is normal, the compressor starts, but quickly heats up and knocks out the thermal relay. The current consumption will be higher than the rated current. Such a motor requires urgent replacement, as it can short-circuit at any time.
Is it worth repairing or replacing the compressor?
The question of economic feasibility comes to the fore when diagnostics have confirmed the death of the compressor. Repairing the motor itself (rewinding) under service conditions is possible, but its cost is often close to the price of a new unit, and reliability will be lower.
Replacing a compressor in a refrigerator Atlant is a complex procedure that requires:
- 🔥 A blowtorch or torch for joining copper pipes.
- ❄️ A vacuum pump to remove moisture from the system.
- ⚖️ A scale for precise charging of freon.
- 🧪 The refrigerant itself and the compressor oil.
If you do not have experience and equipment, independent replacement turns into a lottery. Unprofessional soldering can lead to a freon leak after a month, and insufficient vacuum can lead to the formation of an ice plug. In most cases, calling a technician with equipment will be more rational than buying tools for one-time use.
However, if the refrigerator is more than 10-12 years old, it is often cheaper to buy new equipment than to invest in a major overhaul of the old unit. Modern models Atlant and other brands have better energy efficiency and quiet operation.
Is it possible to start a compressor without a relay?
Technically, you can start the motor by applying voltage directly to the working winding, and to the starting winding briefly through a button. But doing this is strictly not recommended for diagnostics under load. Without protection, you risk burning the windings in seconds when jammed or getting an electric shock.
Why does a new compressor get hotter than the old one?
Modern motors often have a higher housing temperature due to design features and the use of other types of refrigerants (R600a instead of R134a). If the temperature does not exceed 90-100 degrees and the refrigerator freezes, this is normal.
How long does the Atlant compressor last?
The average service life of compressors Atlant is 10-15 years, subject to operating conditions. Regular defrosting, cleaning the condenser at the back and the correct location of the refrigerator (not close to the wall) significantly extend the life of the unit.
Do you need to change the filter drier when replacing the compressor?
Yes, definitely. The filter drier is a disposable element. When the system is opened, it absorbs moisture from the air. If you leave the old filter, moisture will enter the new compressor and cause corrosion or freezing in the capillary.