When the refrigerator stops cooling and the compressor makes loud clicks or hums for just a couple of seconds before stopping, most often the culprit is the start relay. This small device is responsible for starting the electric motor by sending an impulse to the winding, and if it fails, the entire cooling system stops. Owners of household appliances often panic, having no idea where to look for this part and how to get to it, but in most cases the problem is solved quite simply.
The location start relay directly depends on the design of the compressor and the model of your refrigerator, be it Atlant, Samsung or Indesit. In classic models with a conventional motor-compressor, the relay is always mounted directly on the side or bottom of the unit itself. You do not need to disassemble the entire body of the fridge compartment or climb into complex technical niches; it is enough to gain access to the back wall of the device.
Before Before starting search and dismantling, be sure to disconnect the refrigerator from the power supply. Working with electrical components requires safety precautions, and no one wants a sudden capacitor discharge or electric shock. Once you have unplugged the cord from the outlet, you can begin a visual inspection of the rear of the housing, where the main element of the refrigeration cycle is hidden.
⚠️ Attention: Before starting any diagnostic work or replacing the relay, make sure that the compressor has completely cooled down. A hot motor can reach a temperature of 80-90 degrees, and an accidental touch will result in a serious burn to the skin of your hands.
Localization of relays on various types of compressors
Understanding that where is the starting relay locatedrequires knowledge of the type of compressor installed in your refrigerator. The vast majority of household models use piston compressors, with a starting protection device attached to the motor shaft through a system of shock absorbers. It looks like a black plastic or metal box, placed directly on three contact pins protruding from the motor housing.
In inverter models, the situation may look different. Here, the engine is controlled via an electronic board, and a classic mechanical relay may be absent as such, or may be integrated into a common control unit. However, if we are talking about a standard breakdown with clicks, we are talking about the classic scheme. In such cases relay is located on the side of the compressor, often covered with a metal casing or plastic cover to protect it from dust and moisture.
Sometimes the relay is hidden in a special protective cup, especially in old Soviet models or refrigerators designed to operate in conditions of high humidity. To get to the part, you will have to remove this cup, which may be secured with latches or screws. It is important not to use excessive force so as not to split the fragile plastic or damage the copper tubes coming from the compressor.
- 🔍 On standard models, the relay is mounted on a contact group on the side of the motor.
- 🛡️ In some cases, the part is hidden under an additional protective casing.
- 🔌 In inverter systems, the relay can be replaced by an electronic control unit.
If you see that a thick wiring harness goes to the compressor, going into the electronic board, and there is no attached plastic “cup” on the motor itself, perhaps in your case the starting function is implemented differently. But for 90% of refrigerators produced in the last 30 years, a circuit with a hanging relay on the side wall is relevant.
Instructions for accessing the start relay
To get to the place where is the start relay, you will need to move the refrigerator away from the wall. Make sure you have a light source handy, as the lower back wall can often be dark and dusty. The access process does not require a complex tool, usually a flat screwdriver and pliers are enough.
☑️ Preparing for access
First, remove the rear metal panel if it blocks access to the motor. Some budget models may not have such a panel, and the compressor is immediately visible. Find the motor itself - it's a heavy black “drum” at the bottom. On its side (less often on top) you will see a plastic box to which a bundle of wires fits. This is the node you are looking for.
Carefully disconnect the wires. Often the connectors fit tightly and have to be slightly loosened. Do not pull on the wires themselves, so as not to break them inside the insulation. Remove the retaining clip or spring clip, if equipped, and pull the relay down, removing it from the compressor contact studs. Do this without jerking so as not to damage the ceramic base of the contacts.
⚠️ Attention: When removing the relay, be careful not to drop it on the floor. Inside the plastic case there are fragile elements (spring, contacts, posistor), which can crumble or lose calibration from impact.
After dismantling, you will be able to examine the markings of the part. This is important for selecting an analogue if the test shows a malfunction. The parameters are usually stamped on the case: voltage, current, type of refrigerant and model number. Write down this data or take a photo to find an exact replacement at a spare parts store.
Visual diagnostics and signs of malfunction
Once you have found out where is the starting relay locatedand removed it, it is necessary to conduct an initial visual diagnosis. Often external signs can tell more about the condition of a part than sophisticated instruments. Shake the relay near your ear: if something rattles inside like dry pebbles, it means that the posistor or contacts have broken down, and the part requires replacement.
Inspect the contacts for carbon deposits or melting. If the plastic turns black or there is a burning smell, this is a sure sign that a short circuit or overload current has passed through the device. In such cases, simply cleaning the contacts rarely helps, since the geometry and electrical conductivity of the material are damaged.
Why does the relay heat up?
The relay heats up due to the passage of high current through the contacts. If the contact is poor (oxidized), the resistance increases, which leads to heating and eventual melting of the housing. Heating may also indicate that the compressor itself “pulls” too much current due to the interturn short circuit of the windings.
Pay attention to the condition of the spring inside (if the relay is collapsible). It should be elastic and free of corrosion. Rust on the internal elements indicates moisture ingress, which is possible when storing the refrigerator in a damp basement or if the seal of the casing is broken. Moisture causes oxidation of the contacts, which ultimately leads to startup failure.
- 👂 A loud knock inside the case when shaking indicates destruction of the posistor.
- 🔥 A burning smell or visible carbon deposits indicate overheating of the contacts.
- 💧 Traces of oxidation or rust indicates moisture penetration.
If there are no external defects, this does not guarantee serviceability. A posistor can lose its properties of changing resistance when heated, remaining externally intact. Therefore, a visual inspection is only the first stage, which should be followed by a check with a multimeter.
Table of typical relay faults
To systematize knowledge about how start relay he behaves during various breakdowns, it is convenient to use a summary table. It will help you compare the symptoms you observe with your refrigerator with the probable cause of the malfunction.
| Symptom | Probable cause in the relay | Recommended action |
|---|---|---|
| Click and silence | Open circuit or burnt posistor | Replacing the relay |
| Humming for 5-10 seconds, then clicking | Sticking contacts or malfunction windings | Checking the compressor and replacing the relay |
| The refrigerator does not turn on at all | Open circuit of the protection or contacts | Calling with a multimeter |
| Frequent on/off | Incorrect operation of thermocouple or relay | Diagnostics of the cooling system |
It is important to understand that a relay malfunction is often a consequence, not a cause. For example, if compressor has a high resistance of the starting winding, it will consume too much current, which will lead to rapid failure of even a new relay. Therefore, when installing a new part, always monitor the motor current consumption.
Replacement process and installation of a new part
If diagnostics have confirmed that starting relay it is faulty, it must be replaced. The process of installing a new part is technically simple, but requires care. Make sure that the new relay fully matches the markings of the old device, especially in terms of the protection trip current.
Place the new relay on the contact pins of the compressor. It should fit tightly, without distortion. Make sure that the “UP” marking or arrow on the relay body is pointing straight up, since the principle of operation of the device often depends on gravity (in relays with a posistor this is less critical, but in older electromagnetic ones it is mandatory). Attach the retaining bracket or spring.
Connect the wires to the contacts. They are usually color-coded or labeled (R, S, C), but it is better to rely on the diagram photographed before disassembly. Make sure the connectors are inserted all the way and are held securely. After this, you can turn on the refrigerator and listen: you should hear a confident start of the motor without a prolonged hum.
⚠️ Attention: If after replacing the relay the situation has not changed (the refrigerator hums and clicks), immediately turn off the device. Perhaps the problem lies in the compressor itself (turn-to-turn short circuit) or in the wiring, and further attempts to start may completely burn out the motor.
Frequently asked questions (FAQ)
Is it possible to repair a burnt-out relay rather than changing it?
Theoretically, some craftsmen open the case, clean the contacts with sandpaper and replace the posistor. However, the service life of such a restored device will be unpredictable. Considering the low cost of a new relay, the risk of repeated breakdown and possible damage to the compressor makes replacing with a new part the only reasonable solution.
Why does the relay click, but the refrigerator does not start?
The click means that the protection is activated, opening the circuit. This occurs if the starting current is too high (the compressor is faulty) or if the relay cannot close the starting winding (the relay itself is faulty). Also, the reason may be low voltage in the network, which is not enough for a reliable start of the motor.
How to distinguish a relay from a thermal relay?
The starting relay is attached directly to the contacts of the compressor and has a black plastic case. The thermal relay (temperature sensor) is usually located inside the refrigerator compartment or in the evaporator area and looks like a small capsule on a long wire, often in a copper or plastic tip.
Does the brand of the refrigerator affect the type of relay?
Yes, manufacturers use different types of compressors (Danfoss, Secop, LG, Samsung), and relays are selected specifically for a specific motor series, and not just for the refrigerator brand. Therefore, when replacing, it is important to look at the parameters of the old relay, and not just at the name of the refrigerator.
How long does a starting relay last on average?
The average service life of a high-quality starting relay is 5-7 years of active use. However, with frequent power surges in the network or unstable operation of the compressor, this period can be reduced to 2-3 years. Regularly checking the voltage in the network can extend the life of the part.