A sudden stop of operation of the refrigerator or the appearance of a characteristic hum without subsequent starting of the motor often indicates a malfunction of the start-up relay. This small part is responsible for supplying voltage to the motor windings and protecting against overloads, so its failure completely paralyzes the operation of the cooling system. Before calling a technician or buying a new compressor, it makes sense to check this particular element, since replacing it is one of the most accessible procedures in self-repair of household appliances.
The dismantling process requires care and compliance with safety measures, since you will be working with electrical components and mechanical connections. It is important to understandthat the design of the relay may differ depending on the model of the refrigerator and the manufacturer of the motor, however, the general principle of their location and fastening remains similar. In this article, we will analyze all the nuances of removing a part so that you can diagnose or replace without the risk of damaging expensive equipment.
It is worth noting that before starting any work, you must completely turn off the power to the unit by unplugging the power cord from the outlet. Even if the refrigerator is not working, there may be life-threatening voltage remaining in the circuits. After this, you can begin to prepare the workplace, ensuring good access to the rear of the equipment.
Preparation of the workplace and the necessary tools
The success of the relay dismantling operation half depends on proper preparation. You will need some free space to place the refrigerator as the compressor is accessible from the rear. Make sure that the floor is level and clean, and that the lighting in the work area is bright enough to see small details and wire markings.
For work, you will need a minimum set of tools, which are usually found in every home. The main tool will be a flat-head screwdriver, preferably with a thin blade, for prying up the plastic latches and removing the terminals. Pliers or round-nose pliers may also be useful for working with clamps, and in some cases, a multimeter to subsequently check the serviceability of the removed element.
- 🛠️ Flat-head screwdriver with a thin blade for dismantling fasteners
- 🔧 Pliers or side cutters for working with wires
- 📱 Smartphone with a camera for photographing the connection diagram
- 🧤 Dielectric gloves for additional protection
Pay special attention to the organization of lighting. The shadow of the refrigerator body may fall on the compressor compartment, making it difficult to see. Use an additional light source, such as a headlamp or portable lamp, to clearly see contact groups and the condition of the wire insulation.
⚠️ Attention: Never start disassembling if the refrigerator has just been turned off after a long period of operation. The compressor and surrounding pipes may be hot, increasing the risk of burns. Let the unit cool for 30-40 minutes.
Access to the compressor compartment and locating the relay
After the refrigerator is moved away from the wall and de-energized, you need to gain access to the motor. In most modern models, the compressor is located in the lower rear part of the housing and is covered with a metal or plastic casing. This casing is secured with bolts or latches that need to be carefully removed.
Removing the cover, you will see a black cylindrical or pear-shaped object - this is it compressor. The relay in this case is a small box placed directly on the side of the motor rod. It can be black, white or gray, sometimes hidden under additional insulation or a fixing bracket.
To avoid getting tangled in the wires, immediately take a close-up photo of the assembly. The connection diagram from different manufacturers (for example, Atlant, Indesit or Beko) may have its own specific terminal locations. The photo will become your insurance during assembly, allowing you to quickly restore the correct connection.
Sometimes access to the relay can be difficult due to the dense arrangement of the tubes or the presence of additional sensors. In such cases, proceed slowly, being careful not to bend the copper condenser tubes. Mechanical damage The tubes will cause a freon leak and will require expensive professional repairs with refrigerant refills.
Types of start-up relays and their features
Before removing the part, it is useful to know what type of device you are dealing with. This affects the method of dismantling and subsequent inspection. The main difference lies in the principle of operation and the design of the housing, which determines the algorithm of your actions.
There are two main types of relays: posistor and induction. PTC models, which are often found in refrigerators LG and Samsung, have a ceramic element (posistor) inside that changes resistance when heated. Induction relays, typical for older models and equipment Atlant, use an electromagnetic coil and a bimetallic plate.
| Characteristics | Posistor relay | Induction relay |
|---|---|---|
| Principle of operation | Crystal heating | Electromagnetic field |
| Location | Often on top or side | Usually on the side of the rod |
| Check | Continuity tester | Visual inspection and continuity |
| Resource | High | Average |
You can visually distinguish them by markings and shape. PTCs often have a more compact plastic case with several terminals, while induction ones can be more massive. Understanding the type of device will help you correctly interpret the diagnostic results if you decide to check it with a multimeter after removal.
Is it possible to change relay types?
Theoretically, it is possible to replace an inductive relay with a posistor relay, provided that the electrical parameters and the seat match, but it is better to install the original part recommended by the refrigerator manufacturer.
Algorithm for removing the relay from the compressor shaft
The process of removing the relay itself requires caution, since plastic cases become fragile over time. The first step is always to disconnect the electrical wires. The terminals may fit tightly, so they must be carefully loosened from side to side, holding the terminal itself, and not the wire, so as not to break the wire.
After disconnecting the wires, you must remove the fixing bracket or strip, if present. In some models, the relay is simply put on the rod and is held in place due to a tight fit and weight, in others it is fixed with a metal U-shaped bracket, which must be pressed out with a screwdriver. Act smoothly, without sudden jerks.
☑️ Algorithm for removing the relay
To remove the part itself, take the body with both hands and pull it away with light rocking movements motor shaft Do not use excessive force up or down so as not to break the compressor rod. If the relay cannot be removed, it may be stuck or rusted - in this case, you can carefully treat the joint with a penetrating lubricant (for example, WD-40), but make sure that liquid does not get inside the contacts.
After successful dismantling, inspect the seat on the shaft. There should be no oxides or carbon deposits. If you find traces of overheating or melting of the plastic on the relay itself, this is a sure sign that the part requires replacement. Also check the condition of the contacts on the wires - they should be clean and not oxidized.
⚠️ Attention: When removing the relay, make sure that moisture, dust or metal objects do not get inside the open compressor. Any extraneous inclusion inside the motor can cause it to jam the next time it is started.
Diagnostics of the removed element and troubleshooting
When the relay is in your hands, you can carry out its initial diagnostics. A visual inspection often reveals more information than meets the eye. Shake the part near your ear: if a rattling sound is heard inside, as if sand or ceramics were falling, it means that the posistor is destroyed and the relay is definitely faulty.
For a more accurate check, use a multimeter switched to resistance measurement mode. Call the contacts according to the diagram. In good condition, the resistance between certain contacts should be close to zero or have a specific value (for posistors - several tens of Ohms in a cold state). Infinite resistance or a short circuit indicates an internal break or breakdown.
Pay attention to the state of the contacts inside the plastic case. If they are blackened, melted or covered with a green oxide coating, normal operation of the refrigerator is impossible. Poor contact leads to heating, sparking and repeated breakdowns. In such cases, cleaning the contacts rarely has a long-term effect; it is better to replace the entire assembly.
If you plan to install the relay back (for example, to test a hypothesis), make sure that it sits all the way on the shaft and snaps into place. Incomplete seating will result in the motor not starting or operating intermittently, producing loud clicks.
Frequent errors during dismantling and installation
Despite the apparent simplicity of the operation, beginners often make mistakes that can lead to new problems. One of the most common is an attempt to remove the terminals by pulling the wires themselves. This leads to a break in the core inside the insulation, and it can then be very difficult to find the break point. Always grasp only the plastic or metal terminal tip.
Another mistake is ignoring the markings when connecting. The contacts may look the same, but have different purposes (phase, neutral, starting winding). By mixing them up, you risk burning out the compressor winding or the new relay in the first seconds after switching on. Use the photo you took earlier or the markings on the body (R — run, S — start, C — common).
- ❌ Trying to remove the relay by force without removing the fixing bracket
- ❌ Using conductive lubricants to facilitate removal
- ❌ Ignoring the insulation state of suitable wires
- ❌ Installing the relay “for bending”, without a tight fit on the shaft
Also, do not use aggressive solvents to clean the contacts, which can melt the plastic case. After cleaning, be sure to let the part dry completely before installing.
If after cleaning. Replacing the relay, the refrigerator started working, but after a while it stopped starting again, the problem may be deeper. Perhaps the compressor itself is faulty (an interturn short circuit) or there is a freon leak. In such cases, simply replacing the relay gives only a temporary effect.
What to do if the new relay does not fit?
If the purchased part is visually different or does not fit. shaft, do not try to adjust it by force. Check the markings: the relays are selected according to the compressor power and the type of refrigerant. Using the wrong relay can lead to the fact that it will not turn off the starting winding, which will burn the motor.
Is it possible to repair the relay rather than change it?
Theoretically, if the problem is only oxidation of the contacts, they can be cleaned. However, the service life of the restored relay will be low, and the risk of repeated breakdown of the compressor will be high. Given the low cost of new parts, repairing the old relay is not economically feasible.
Why does the relay burn out repeatedly?
Frequent combustion of the relay indicates problem in the system: this could be a malfunction of the compressor (stiff running, short circuit), power surges in the network, or incorrect selection of the part itself. Before installing the next relay, you need to find and eliminate the root cause.