Sudden clicks coming from kitchen appliances often become a cause for concern, especially when they are accompanied by a lack of cold. Relay in the refrigerator it performs critically an important function, starting and stopping the compressor, so any changes in the nature of its sound signal processes within the system. If you hear the mechanism clicking frequently, this may mean either normal operation of the thermostat or a serious breakdown that requires intervention.
In normal operation, the unit makes barely audible sounds when switching modes, but an obsessive clicking sound or a series of clicks before attempting to start the engine is already a symptom. Start-protective relay takes responsibility for supplying voltage to the motor windings, and if this process is disrupted, the equipment will not be able to cool the products. Understanding the nature of these sounds will help you quickly navigate the situation and make the right decision on further actions.
In this article we will analyze in detail the design of the trigger mechanism, the reasons for its frequent operation and diagnostic methods available at home. You will find out why compressor it can hum and click without starting, and in which cases replacing the part will completely solve the problem. A careful study of the symptoms will allow you to avoid more expensive repairs in the future.
Principle of operation of the start-up relay
To understand the source of the problem, it is necessary to consider the design of the device responsible for starting the engine. Starting relay is an electromagnetic switch that supplies a current pulse to the starting winding of the compressor only at the moment of switching on. As soon as the motor reaches the required speed, the current in the circuit drops and the mechanism opens the contacts, stopping the supply of energy to the starting winding.
In parallel with the starting function, thermal protection, built into the same housing or located nearby, often works. Thermal relay controls the current flowing through the motor and opens the circuit when overloaded or overheated, preventing the windings from burning out. It is the combination of these two functions that ensures safe and stable operation of the refrigeration unit.
⚠️ Attention: Inside the relay housing there is a fragile nichrome spiral and a bimetallic plate. Do not shake the part sharply or knock on it, as this can lead to irreversible damage to the internal contacts.
The startup process is as follows: when voltage is applied, the contacts close and current flows to the windings. If the engine is working properly, it starts and the relay clicks, breaking the starting circuit. If the start does not occur, the protection is triggered again after a certain interval, creating a characteristic rhythmic sound.
How does an electromagnetic relay work?
Inside the plastic case there is a coil with a movable core. When current is applied, the core retracts and closes the contacts. The thermal relay uses a bimetallic plate, which bends when heated by current and opens the circuit.
Main reasons for frequent clicking
There are several key factors due to which the refrigerator begins to make alarming sounds. Most often, the problem lies in wear of the switching mechanism itself or a change in engine operating parameters. Contact wear leads to the formation of carbon deposits, which increases resistance and causes sparking, accompanied by a loud click.
Another common reason is the failure of the compressor windings. If an interturn short circuit occurs in the motor coils, current consumption increases sharply. In this case, thermal protection works almost instantly after the start attempt, opening the circuit and making a sound, after which the cycle is repeated again and again.
- 🔌 Oxidation of contacts at the junction of the relay and the compressor, which prevents poor current conductivity.
- 📉 Voltage drop in the electrical network, due to which the engine does not have enough power to start.
- 🧊 Freezing or jamming of the compressor itself, which creates mechanical resistance.
- 🔥 Overheating of the motor housing due to poor ventilation or high ambient temperature.
It is also worth considering the condition of the wiring. If the cable going from the socket to the appliance is damaged or has poor contact in the plug, this can cause voltage surges to which the sensitive automatic equipment of the refrigerator reacts. Frequent clicks at intervals of 2-5 minutes most often indicate the thermal relay is triggered due to the inability to start the engine.
Diagnostics: normal or broken
Not every sound should cause panic, so it is important to learn to distinguish normal operation from an emergency situation. If the click is heard once when the refrigerator is turned on and once when it is turned off (when the set temperature is reached), then this is the normal operating mode of the lator and starter. In this case, the equipment functions correctly. thermoreglator and starter. In this case, the equipment functions correctly.
The alarm should be sounded if the clicks become a series. For example, a click is heard, the compressor hums for a few seconds, then another click follows and silence. After 2-3 minutes the cycle repeats. This indicates that starting device is trying to start the motor, but the protection turns it off due to overload or lack of rotation of the rotor.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| Single click at start | Normal operation | No supervision required |
| Series of clicks without starting | Relay or compressor fault | Replacing the relay, checking the windings |
| Clicks and humming | Motor jammed | Call a technician, compressor repair |
| Crackling and sparking | Burning of contacts | Urgent replacement of the relay |
For accurate diagnostics, you can use a multimeter. By ringing the relay contacts in a cold state, you should see a short circuit on certain pairs of contacts. If the device shows an open where there should be a circuit, or a short circuit, the part requires replacement.
☑️ Sound diagnostics
How to replace the start relay with your own hands
If diagnostics showed that the problem is in the relay, you can replace it yourself, without having in-depth knowledge of electronics. The first step is to completely turn off the power to the refrigerator by removing the plug from the socket. This is a critical safety precaution as work will be carried out on electrical components.
Get to the compressor, which is usually located at the lower rear of the unit. Remove the protective plastic cover, if equipped, and inspect the black cylindrical or box-shaped element that fits onto the motor stem. Carefully remove the old relay, disconnecting the wires, and remember their connection diagram or take a photo.
⚠️ Attention: The new relay must strictly correspond to the model of your compressor. The parameters (power, type of refrigerant, installation orientation) must match, otherwise the engine will burn out.
Install the new part on the compressor rod until it clicks into place and connect the wires in accordance with the previously made marks. Make sure all connections are tight and secure. After assembly, turn on the refrigerator and listen to the first start-up cycle: the motor should work smoothly, without unnecessary sounds.
Problems with the compressor and electrical network
Sometimes replacing the relay does not bring results, and the refrigerator continues to click. In this case, the reason lies deeper - in the engine or external conditions. If the compressor hums but does not start even with a new relay, the piston mechanism may be jammed or a breakdown of the windings has occurred.
Check the voltage in your electrical network. At low voltage (below 190 Volts), the starting torque may not be enough to turn the motor shaft. Under such conditions, the relay will constantly click, trying to start the unit, which will ultimately lead to its breakdown. To solve the problem, you will need to install a voltage stabilizer.
You should also pay attention to the thermostat. If its contacts are stuck in the "on" position, the compressor will run continuously, overheat, and eventually the thermal protection will trip, causing a clicking sound. Checking the thermostat involves closing its contacts directly to eliminate this version.
- ⚡ Check the integrity of the power cord and plug for melting.
- 🌡️ Make sure that the refrigerator is not too close to the wall for good ventilation.
- 🔧 Try lightly knocking on the body compressor (carefully!) when humming - sometimes this helps to move a jammed shaft.
Prevention and service life of parts
To extend the life of the start relay and compressor, you must follow the operating rules of the refrigerator. Regular cleaning of the condenser (grid at the back) from dust ensures good heat transfer and prevents overheating of the motor. Overheating is the main enemy of electrical components.
It is not recommended to turn the refrigerator off and on. The minimum interval between turning off and turning on again should be at least 5-10 minutes. This time is necessary to equalize the pressure in the system and cool down the thermal protection, otherwise the restart will take place with an increased load.
The average service life of a high-quality starting relay is 5-7 years, but with frequent power surges it can shrink. If you live in an area with an unstable power grid, installing a voltage control relay will be the best prevention of breakdowns of your equipment.
Is it possible to repair an old relay rather than changing it?
Theoretically, you can try to clean the contacts from carbon deposits if the case is collapsible. However, in modern models, relays are often sealed or made disposable. Considering the low cost of a new part, repairing an old one is usually impractical and less reliable.
Why does the relay click, but the refrigerator does not freeze?
This means that the compressor does not start. The relay gives an impulse, but the motor does not rotate (due to jamming or breakage of the windings), the protection is triggered and turns off the power. No cold is produced since the refrigerant does not circulate through the system.
Is it dangerous to continue using the refrigerator if it clicks?
Operation in this mode is dangerous. Frequent starting attempts can lead to complete combustion of the compressor windings, which will require an expensive replacement of the motor or the entire refrigerator. It is better to turn off the device until the reasons are determined.