The situation when your refrigerator turns on and after a few seconds a loud click is heard, after which the unit goes silent again, is one of the most common and frightening breakdowns. This phenomenon in the technical environment is often called “cycling” or protective shutdown. The compressor tries to start, but the protection system detects a critical error or overload and emergency breaks the electrical circuit to prevent more serious damage to the engine.
It is absolutely impossible to ignore this operating mode, since each such start cycle creates a colossal load on the electric motor windings. If the cause is not eliminated in time, the situation can lead to an interturn short circuit or a complete wedge of the piston group. In most cases, the problem lies in one of three components: the start relay, the thermostat or the compressor itself.
In this article we will analyze in detail the mechanics of the process, methods of self-diagnosis and determine when it is necessary to call a specialist, and when you can handle it on your own. Understanding the nature of the click will help you save significant money on diagnostics and, possibly, avoid purchasing new equipment.
The principle of operation of compressor protective mechanisms
To understand why a failure occurs, you need to understand the basic logic of the refrigeration unit. When voltage is applied to compressor the current passes through the starting relay, which sends an impulse to the starting winding, helping the motor to spin up. In normal operation, this process takes a fraction of a second, after which the relay turns off the starting winding, and the engine runs only on the working one.
If the motor cannot reach the required speed due to mechanical jamming or electrical failure, the current in the circuit increases sharply. This increase in current is recorded thermal protection relay, which is heated by a special plate. As soon as the temperature of the plate reaches a critical point, the contacts open and the same click that you hear is heard.
⚠️ Attention: Frequent attempts to turn on without eliminating the cause lead to overheating of the windings and destruction of the insulation of the wires inside the motor, which makes repairs economically impractical.
There is also a possibility of a malfunction of the control element itself. If the contacts inside the start relay are stuck or do not close correctly, the engine will receive the wrong impulse to start. In modern inverter models, diagnostics are carried out by an electronic module that turns off the power when anomalies in the winding resistance are detected.
Faults in the start-up relay
The most common reason that the refrigerator clicks and does not start is the failure of the start relay. This small plastic block, mounted on the side wall of the compressor, is responsible for supplying the starting impulse. Inside it there is a coil or posistor, which wears out over time. In older models with electromagnetic relays, the coil often burns out or the contacts burn out, which is why the relay hums but does not complete the circuit.
More modern units use posistor relays, which have no moving parts, but are sensitive to voltage surges. If the posistor is “broken,” it can constantly pass current to the starting winding, causing a hum and subsequent shutdown of the protection. It is also worth checking the condition of the contacts: if they are oxidized, the current simply will not reach the motor.
- 🔌 Visual inspection: Remove the casing at the back of the refrigerator and carefully disconnect the relay. Shake it: if something rattles inside, it means that the core or contacts are damaged, and the part requires replacement.
- 🔥 Odor burning: The presence of a characteristic smell of burning plastic or burnt insulation in the relay area indicates overheating and melting of the internal components.
- ⚡ Checking with a tester: Ring the contacts with a multimeter. In a cold state, the resistance between certain contacts should be zero or close to it, depending on the type of relay.
Replacing a relay is one of the simplest procedures in repairing household appliances. However, it is important to select an exact copy of the device, since even the same manufacturer may use different modifications for different series of compressors. An incorrectly selected relay may not start the motor or, worse, burn its windings.
Problems with the thermostat and sensors
The thermostat (thermostat) is the “brain” that gives the command to turn on the compressor when the temperature in the chamber rises above the set one. If this element is faulty, it may produce short, intermittent signals or not make contacts at all. In mechanical thermostats, the spring often weakens or the seal of the bellows tube filled with freon is lost.
In refrigerators with a system No Frost and electronic control, instead of a mechanical thermostat, there are air temperature sensors. If such a sensor “lies” and shows that the chamber is already cold, the compressor may not turn on at all or work in very short cycles. Sometimes the contacts at the junction of the sensor and the control board oxidize.
Thermostat diagnostics are often carried out by the method of exclusion. If, when the thermostat contacts are closed directly (bypassing the regulator), the refrigerator starts and operates normally, then the problem is in this unit. However, this number will not work with electronic modules - it requires checking the resistance of the sensor at different temperatures.
⚠️ Attention: When replacing a mechanical thermostat, it is important not to bend or damage the capillary tube, otherwise the refrigerant inside it will evaporate, and the new thermostat will also not work.
It is also worth mentioning defrost button, which is found on some older models. If it jams or closes incorrectly, this can simulate a thermostat malfunction, interrupting the compressor power circuit at the most inopportune moment.
Interturn short circuit and compressor problems
The most unpleasant scenario is a malfunction of the very heart of the refrigerator. Interturn short circuit occurs when it is broken insulation between the turns of the copper stator winding of the motor. As a result, some of the turns are short-circuited, the resistance drops, the current increases sharply, and the thermal relay instantly turns off the device. The compressor may hum quietly or emit a low-frequency hum before clicking.
Another common problem is mechanical. compressor wedge. This happens when freon leaves the system along with the oil, or the oil loses its properties and thickens. The piston group gets stuck and the engine physically cannot turn over. Attempts to start a “jammed” unit lead to combustion of the starting winding or the compressor itself.
For diagnostics, the method of “starting bypassing the relay” is often used using a special starting-charging device (ROM). If the motor starts and runs with the ROM, it means the problem was in the relay or wiring. If a protection click is heard from the ROM after 3-5 seconds, the probability of a compressor malfunction is more than 90%.
| Symptom | Probable cause | Sound character | Actions |
|---|---|---|---|
| Buzzing for 3-5 seconds, click | Compressor jammed | Low hum turning into silence | Attempt to start ROM or replacement |
| Quiet click, silence | Relay malfunction or break | Single dry click | Replacement of the starting relay |
| Works for 10-20 seconds, click | Lack of freon or wedge | Even hum, then a click | Checking freon pressure |
| Humming constantly | Thermostat malfunction | Even hum without shutdowns | Replacing the thermostat |
It is important to understand that repairing a hermetic compressor at home is impossible. If an interturn short circuit or wedge is confirmed, the unit must only be completely replaced. Attempts to “revive” the motor by applying increased voltage or striking the housing are temporary and dangerous.
The influence of voltage drops and wiring
External factors cannot be ignored. If your electrical network experiences constant voltage surges or is chronically low (below 190 volts), the compressor may simply not have the power to start. At low voltage, the starting torque of the engine drops, it cannot overcome the pressure in the system and “gets stuck,” which triggers the protection.
It is also worth paying attention to the condition of the socket and extension cords. Using cheap Chinese extension cords with thin wires for powerful appliances like a refrigerator is a bad idea. The voltage at the input to the refrigerator can drop critically low precisely at the moment of start, when current consumption is maximum.
- 🏠 Checking the voltage: Use a multimeter to measure the voltage in the outlet when you try to turn on the refrigerator. If it drops below 180-190 V, the problem is in the electrical network at home.
- 🔌 Exclusion of extension cords: Always plug the refrigerator directly into a fixed outlet. The extension cord creates additional resistance.
- 🛡️ Stabilizer: If power surges in your home are the norm, installing a voltage stabilizer is mandatory to extend the life of the equipment.
Sometimes the problem lies in the bad contact in the refrigerator plug itself or at the point where the wire enters the housing. Oxidized contacts create resistance, heating and voltage drop, which simulates the symptoms of a faulty compressor.
Specifics of operation of inverter compressors
Modern models of refrigerators (for example, Samsung, LG, Bosch) use inverter compressors, which are fundamentally different from classic ones. They do not have a starting relay in the usual sense and start smoothly under the control of an electronic module. If such a refrigerator turns on and immediately turns off, most often the electronics are to blame, not the mechanics.
The inverter control module constantly monitors current, voltage and rotation speed. In case of any anomaly (for example, a power surge in the network or a malfunction of the Hall sensor inside the compressor), the module goes into protection and stops supplying power. Diagnostics of such systems requires special equipment and knowledge.
A common mistake owners make is trying to find a starting relay on an inverter motor - it simply isn’t there. The role of the starter is performed by the control board. If it burns out due to a power surge, the compressor will not receive a command to start or will receive erroneous signals.
⚠️ Attention: Inverter compressors are very sensitive to the quality of soldering of the tubes when charging with freon. Ingress of moisture or air during unqualified repairs can quickly damage an expensive unit.
Repair of inverter systems often comes down to replacing the control module or the compressor assembly itself. Soldering boards yourself or replacing components inside the inverter without factory conditions, as a rule, does not give a long-lasting result.
Algorithm of actions when a malfunction is detected
If you encounter the problem described, do not panic and act consistently. First, turn off the power to the refrigerator and let it cool for 2-3 hours. Sometimes the thermal relay needs time to cool down and close the contacts again. After cooling, try plugging the unit into another, known-to-work outlet without an extension cord.
If the situation repeats, carefully remove the back cover (with the refrigerator unplugged!). Inspect the wires for melting, check the tightness of the contacts. If you have the skills and a multimeter, you can ring the compressor windings and check the relay. However, if you are not confident in your abilities, it is better not to risk it.
If the problem cannot be solved by replacing the relay or checking the socket, you need to call a professional technician.
The technician will arrive with a pressure gauge station and a tester, and will accurately determine the pressure in the system and the current consumption of the compressor. This will allow you to make an accurate diagnosis: whether to change the compressor, look for a freon leak, or change the electronics. Timely repairs will cost less than buying a new refrigerator.
Is it possible to temporarily use a refrigerator if it turns off after 5 seconds?
It is strictly not recommended. Each such cycle is a page