The situation when the refrigerator turns on and immediately turns offis a classic sign of a serious malfunction in the engine starting system. Often this process is accompanied by a characteristic click, buzz or crackling sound, followed by silence. Owners of household appliances are faced with the fact that the motor is trying to start, but the protective automation immediately interrupts the supply of electricity to prevent overheating and failure of expensive components.
Ignoring this symptoms can lead to complete combustion of the compressor, the replacement of which often not economically feasible. It is important to understand that in 80% of cases the problem lies in one of three elements: the start relay, the compressor itself or the thermostat. Further operation of equipment in this mode is strictly prohibited, since each cycle of “attempt to start” depletes the life of the electric motor windings.
In this article we will analyze in detail the mechanics of the process, explain why the protection is triggered, and determine the procedure for self-diagnosis. You will learn how to distinguish a cheap relay breakdown from critical damage to the heart of the refrigerator - motor-compressor.
Failure mechanics: why the thermal relay is triggered
To understand the essence of the problem, you need to consider the operating cycle of the starting device. When you turn on the refrigerator, current is supplied to the windings of the electric motor. If the motor rotor is jammed or the starter cannot produce the required torque, the current in the circuit increases sharply. This phenomenon is called short circuit or overload current.
The design of the refrigerator provides thermal protection relaywhich responds to a critical increase in temperature or current. It breaks the circuit and you hear a clicking sound. After some time, the bimetallic strip inside the relay cools down, closes the circuit again, and the cycle repeats. This process can last indefinitely until you unplug the device.
⚠️ Attention: If you hear periodic clicks every 30-60 seconds, immediately unplug the plug from the socket. Continuation of such cycles is guaranteed to lead to an interturn short circuit in the compressor windings, which will make its repair impossible.
A frequent reason for this behavior is a voltage drop in the network or, conversely, its surges. However, if the electricity in your network is stable, then the problem lies inside the unit. It is important to check whether the compressor housing itself has overheated - if it is hot to the touch immediately after the click, it means that the overload current was significant.
Diagnostics of the starting and protective relay
The most likely candidate for replacement is starting relay. This small plastic block is attached to the side or bottom of the compressor and is responsible for sending an impulse to the starting winding. In older models of refrigerators, such as ZIL, Biryusa or early Indesit, electromechanical relays are used, which wear out over time.
Inside the relay body there is a coil and a movable core. Over time, the contacts may burn out and the spring may lose its elasticity. As a result, the core does not rise to the desired level, the contacts of the starting winding do not open in time, or they do not close at all to start. Visually, black carbon deposits or melted plastic are often visible on the contacts.
Replacing the relay is the simplest and cheapest procedure for restoring the operation of the refrigerator.abilities . However, when installing a new part, it is important to ensure that it is the correct capacity and type for your compressor. Universal relays exist, but it is better to select an original or a high-quality analogue that matches the markings on the engine housing.
Compressor malfunctions: jamming and breakage
If replacing the relay did not help, or a check showed its serviceability, the problem lies deeper. The most unpleasant reason why the refrigerator hums and turns off is mechanical jamming of the compressor piston group. The metal parts inside the sealed casing could wear out, collapse, or the oil could thicken and turn into tar, blocking the movement of the pistons.
In this state, the engine is physically unable to turn the shaft. The current consumed when trying to start instantly reaches peak values, which triggers the protection. Sometimes the compressor can be “unwedged” by applying voltage directly to the starting winding through a capacitor, but this is a temporary measure that will only delay the purchase of a new unit.
Another possible malfunction is in the stator windings. In this case, the resistance of the windings drops, the current increases, and the thermal protection turns off the device again. You can check this by measuring the resistance of the windings with a multimeter. Normal values are usually in the range of 20-40 Ohms for the starting winding and 10-15 Ohms for the working winding (values depend on the model). turn-to-turn short circuit in the stator windings. In this case, the resistance of the windings drops, the current increases, and the thermal protection turns off the device again. You can check this by measuring the resistance of the windings with a multimeter. Normal values are usually in the range of 20-40 Ohms for the starting winding and 10-15 Ohms for the working winding (values depend on the model).
Diagnostics of the compressor requires caution. If you do not have experience working with electrical appliances under voltage, it is better to entrust this work to a professional, since the risk of getting an electric shock or completely finishing off the unit is very high.
The role of the thermostat and temperature sensors
You should not discount the temperature control system. Thermoregulator (thermostat) is a device that gives a command to turning on the compressor when the temperature in the chamber rises. If the thermostat contacts are “stuck” or the mechanism is faulty, it may send short pulses or not give a command to fully start.
In modern models with electronic control, the temperature sensor and control module are responsible for this. If the sensor “lies” and shows that the temperature has already been reached, the compressor may not turn on at all or work in a ragged rhythm. However, the “turned on - immediately turned off” scenario is more typical for mechanical problems of the motor or relay.
To check the thermostat in older models, you can close its contacts directly. If after this manipulation the refrigerator starts working normally (and does not turn itself off until it is turned off manually), then the culprit has been found. In modern systems, diagnostics of the control board will be required.
| Symptom | Probable cause | Sound character | Action |
|---|---|---|---|
| Click after 2-5 seconds | Faulty starting relay | Quiet click, no buzzing | Replacing the relay |
| Humming and clicking | Compressor jammed | Strong humming turning into a click | Repair or replacement of the compressor |
| Crack and silence | Break winding | Single crack, silence | Replacement compressor |
| Works jerkily | Problems with the thermostat | Depends on the model | Checking/replacing the thermostat |
Problems with electrical wiring and socket
Before disassembling the refrigerator, it is worth eliminating external factors. Sometimes the reason is trivial: poor contact in the socket or plug. If the connection is loose, resistance occurs when current is applied, the voltage drops, and the compressor cannot start, going into protection.
Check whether the plug or extension cord is hot if you are using it to connect the refrigerator. Using extension cords for high-power appliances such as refrigerators is not recommended, especially if the cord is thin. It is also worth checking the circuit breaker in the panel - perhaps it is faulty and trips at the slightest load.
Inspect the power cord of the refrigerator itself. On older models, the insulation could dry out and crack, which could cause a short circuit when the hose moves. In this case, the entire power cable needs to be replaced.
Features of diagnostics of inverter models
If you have a modern refrigerator with a system No Frost and an inverter compressor, the situation changes dramatically. In such models there is no classic starting relay, and starting is carried out smoothly through an electronic control module. If such a refrigerator turns on and immediately turns off, or blinks indicators, the problem is almost certainly in the electronics.
The inverter compressor does not make loud clicks when starting. Its failure most often looks like an attempt to overclock, vibration and a sudden stop. Diagnostics here is impossible without special equipment for checking modulator signals. You can independently only check the integrity of the wires going from the board to the compressor.
⚠️ Attention: In inverter models (you should not) try to supply voltage to the compressor directly or change the “relay”, since it simply is not there. This will lead to the burning of an expensive control board.
For owners of inverter equipment, the only correct solution for such symptoms is to call a technician with diagnostic equipment. The error may lie in the compressor itself, in the control board or in the rotor position sensors.
Frequently asked questions (FAQ)
Is it possible to operate the refrigerator if it clicks and turns off?
Absolutely not. Each such cycle is a thermal load on the windings, which can lead to their burnout. In addition, a hydraulic shock may form in the oil circulation system, which will damage the valves.
How much does it cost to replace the start relay?
The relay itself is inexpensive (usually from 500 to 1500 rubles depending on the model), but if you call a technician, the cost of the work will make up the bulk of the amount. Self-replacement takes 15 minutes.
Why does the refrigerator turn on 20 minutes after it is turned off?
This time is necessary for the thermal protection relay to cool down and equalize the freon pressure in the system. If the pressure is not equalized, the compressor will not be able to turn the pistons. This is normal behavior of the protective system.
Could the cause be a lack of freon?
Lack of freon itself rarely causes an instant shutdown. However, if the leak allows air and moisture to enter the system, ice or acid may form and eventually jam the compressor. But the primary symptomatology is usually different - poor cooling.