Sudden stoppage of work refrigeration equipment Liebherr often causes panic, especially when there are perishable products inside. However, in many cases the problem lies not in complex electronics or freon leakage, but in the failure of the compressor start relay. This small but critical element is responsible for starting the engine, and its replacement is one of the most common procedures in self-repair of household appliances.
Before disassembling, you must make sure that the refrigerator is disconnected from the power supply, since working with electrical components requires compliance with safety measures. Start relay in models Liebherr usually located in close proximity to the compressor, which is located at the lower rear of the unit. To access it, you do not always need to remove the back cover; sometimes it is enough to simply move the equipment away from the wall.
This procedure requires a minimum set of tools and basic technical skills, which makes it accessible to most owners. It is important to understand that proper diagnosis before removing a part will help avoid unnecessary costs for parts that may not be needed. In this article, we will analyze the dismantling process in detail, consider typical faults and answer frequently asked questions.
Diagnostics of a faulty starting relay
The first sign of problems with the starting device is a characteristic click, which is heard every few minutes, after which the compressor either does not start at all, or hums for several seconds and again falls silent. If at the same time the motor housing remains cold or barely warm, and the light in the chamber is on, then with a high degree of probability it is the protective thermal relay that is faulty. In some cases, the refrigerator may turn on, but not reach the set temperature, working almost without stopping. starting relay or protective thermal relay. In some cases, the refrigerator may turn on, but not reach the set temperature, working almost non-stop.
For accurate diagnosis, it is necessary to visually inspect the part after removing it. Often, traces of burning, melting of plastic or blackening of contacts are observed on the case. If the relay has a ceramic body, the cracks may not be visible from the outside, so an important step is to check the internal contact group and the moving rod for jamming.
⚠️ Attention: If, after removing the relay, you find that the compressor rod (motor shaft) has play or is difficult to turn by hand, the problem may not be in the relay, but in the jammed motor. An attempt to start such an engine with a new relay will lead to instantaneous combustion of the new part.
It is also worth considering that in modern models Liebherr with inverter compressors, the starting system may differ from classic schemes. In such units, the role of the starting device is performed by an electronic control unit, and a mechanical relay may not be available as a class. Therefore, before ordering a spare part, always check the technical documentation or diagram of your specific model.
There is a simple method of initial testing: if you shake the removed relay near your ear and hear a rattling sound, this may indicate destruction of the internal contact group or core, although for some types of devices a slight knocking sound is normal. A more reliable method is to “test” the contacts with a multimeter in different positions, which allows you to identify an open circuit or short circuit.
Necessary tools and workplace preparation
To successfully dismantle the refrigerator start relay Liebherr you will need a minimum set of tools that most home craftsmen will have. The main tool will be a flat-head screwdriver, which will be needed to remove the fixing clips and carefully pry up the latches of the plastic casing. In some cases, a Phillips screwdriver may be required to remove the protective cover of the compressor compartment if it is fastened with screws.
Be sure to have a multimeter (tester) ready to check the integrity of the electrical circuits. Without this device, diagnostics will be purely visual, which does not always provide a 100% guarantee of serviceability. Also, pliers with narrow jaws for gripping wires and, possibly, a flashlight will not be superfluous, since the lighting in the compressor niche is often insufficient.
- 🔧 Flat and Phillips screwdrivers for disassembling fasteners.
- 🔌 Multimeter for checking contacts and windings.
- 🧤 Dielectric gloves for protection against residual current.
- 📸 Smartphone for photographing the connection diagram before removal.
The work place should be well lit, and the space around the back wall of the refrigerator should be free. It is recommended to place cardboard or soft cloth on the floor so that if small parts (screws, springs) fall, they will not get lost and scratch the floor. Before starting any work, make sure that the refrigerator's plug is unplugged.
An important aspect of preparation is to ensure access to the compressor. In some models Liebherr access is closed with a metal or plastic casing, which is secured with latches or screws. It must be removed carefully so as not to damage the fragile plastic elements, which could become brittle over time.
Step-by-step instructions for removing the relay
The process of removing the start relay begins with completely disconnecting the refrigerator from the power supply. This is a safety critical requirement as you will be working in close proximity to live parts and capacitors that can retain charge. After unplugging, move the refrigerator away from the wall, providing access to its rear.
Locate the compressor - this is the black metal tank at the bottom of the unit. On the side or top of it there is a plastic box to which the wires fit. This is the device you are looking for. In models Liebherr it is often closed with an additional protective cover, which must be removed by unscrewing the screws or snapping the fasteners.
☑️ Procedure for removal
Next you need to photograph the location of the wires. Even if you think you can remember which wire is connected where, a photo will be your insurance against assembly errors. After this, carefully remove the retaining bracket (if there is one) that holds the relay to the compressor terminals. Then, rocking from side to side, pull the relay housing down from the motor contacts.
Do not use excessive force. If the relay does not come off, check to see if you forgot to remove any retainer or terminal. Sudden jerks can damage the compressor contacts or break wires, making repairs more difficult. After removal, carefully inspect the inside of the relay for oxides, carbon deposits or mechanical damage.
⚠️ Attention: Never try to remove the relay by pulling the wires. This will lead to broken wires or damaged insulation, which will require extension of wires and soldering, increasing the risk of poor contact in the future.
If oxide or carbon deposits are visible on the contacts, they can be carefully cleaned with fine sandpaper or an eraser, but in the case of a start relay Liebherr most often a complete replacement of the node is recommended, since the internal processes of contact degradation have already started. It is better to recycle the old relay, since its reuse after cleaning rarely gives long-term results.
Types of relays and their markings in Liebherr refrigerators
Refrigerators Liebherr use different types of starting devices, and understanding their differences is important for proper replacement. The most common are posistor (PTC) relays, which operate based on changes in the resistance of a ceramic element when heated. They are reliable and have no moving mechanical parts inside, which makes them less susceptible to wear and tear from vibration.
Another common type is an inductor relay with a moving core. In such devices, when voltage is applied, the coil draws in the core, closing the contacts, and then, when the engine picks up speed, the current drops, and the core, under the influence of gravity or a spring, opens the circuit. It is important to install such relays strictly in a certain position, indicated by the arrow UP or TOP on the body.
| Relay type | Principle of operation | Characteristic symptoms of a malfunction | Features of replacement |
|---|---|---|---|
| Posistor (PTC) | Heating of ceramics and increasing resistance | The refrigerator does not turn on, there are no clicks | Does not depend on orientation in space |
| Electromagnetic | Retracting the core with a coil | Humming, clicking, short-term start-up | Requires strict orientation (up arrow) |
| Combined | Combination of a posistor and thermal protection | Shutdown after a few seconds of operation | Often assembled with a thermal relay |
The marking on the relay body contains information about the manufacturer, operating voltage, current and type of refrigerant for which it is intended. When selecting an analogue for Liebherr it is important to pay attention not only to the geometric dimensions and mounting location, but also to the electrical characteristics, especially the range of operating currents.
Is it possible to use a universal relay?
Universal relays are suitable for many models, but require careful selection by current. If the operating current is too low, the relay will turn off the compressor prematurely. If it is too high, it will not start the engine or will burn out on its own. It is better to look for the original or a complete analogue by catalog number.
Using an unsuitable relay can lead to the compressor operating in emergency mode, constantly overheating and ultimately failing. Therefore, if you are not sure of compatibility, it is better to consult with a specialist or find a correspondence table for your series of refrigerators.
Replacing the faulty part and assembling the system
After the old relay has been removed and diagnosed, a new element is installed. Before installation, make sure that the new part fully matches the old one in terms of connector configuration and electrical parameters. Insert the terminals of the compressor windings into the corresponding sockets of the new relay until a characteristic click or stop occurs.
If the design provides for the use of a fixing bracket or spring clip, install it in place, making sure that it securely holds the relay on the motor terminals. Do not allow distortions, as the vibration of a working compressor can loosen a poorly secured part, which will lead to sparking and burning of contacts.
- 🔌 Check the tightness of the terminals to the compressor contacts.
- 🧊 Make sure that the thermal relay (if it is separate) fits tightly to the motor housing for correct operation protection.
- 🔩 Replace the compressor protective casing and secure it.
Only after thoroughly checking all connections can you turn on the refrigerator. During the first minutes of operation, listen carefully to the startup sound: it should be smooth, without buzzing or repeated clicks. The compressor should pick up speed and operate stably.
During the assembly process, do not forget to return all removed structural elements, including the back panel, if it was dismantled. This is necessary for proper air exchange around the compressor and protection of internal components from dust and moisture.
Common mistakes during self-repair
One of the most common mistakes is ignoring the check of the compressor itself. Replacing a relay on a stuck motor is a waste of money and time. If the motor shaft does not rotate freely (with a certain force, but without jamming), then the problem is deeper, and the intervention of a professional technician with specialized equipment is required.
Another mistake is the incorrect orientation of the electromagnetic relay during installation. As already mentioned, such devices are sensitive to position in space. Installation “upside down” or sideways will lead to the fact that the core will not be able to return to its original position under the influence of gravity, and the contacts will not open, which will cause the winding to burn out.
Some craftsmen try to “reanimate” the old relay by tapping or stripping the contacts. In the conditions of modern household appliances Liebherr this is a temporary measure, which often leads to repeated breakdowns after a few days or weeks. It is safer to immediately install a new certified component.
It is also worth mentioning the error associated with ignoring the condition of the wiring. Often, when removing an old relay, it is discovered that the insulation of the suitable wires has dried out and cracked. If such areas are not replaced or insulated, a short circuit is possible, which can damage the new part or cause a fire.
Is it possible to start a refrigerator without a start relay?
Theoretically, you can start an asynchronous compressor motor by forcibly closing the contacts, but doing this is strictly prohibited in domestic conditions. This requires precise timing of the circuit opening (fractions of a second) and carries a high risk of electric shock, fire or complete failure of the compressor. The refrigerator will not be able to operate in normal cyclic mode without a working starting device.
Why does the new relay burn out immediately after installation?
If the new starting relay burns out instantly or after a short time, this almost always indicates a malfunction of the compressor itself. Most often this is an interturn short circuit in the motor windings or a mechanical wedge of the piston group. In this case, the motor consumes a current significantly higher than the rated current, which leads to overload and destruction of the relay. A specialist needs to diagnose the motor.
Where can I find the markings for selecting an analog relay?
The markings are usually applied to the side or top edge of the plastic housing of the relay itself. Look for the manufacturer's logo (eg Danfoss, Secop, Startech) and alphanumeric code (eg 101N0110 or R600a). Also, the spare part number can be found in the technical documentation of the refrigerator Liebherr or on the sticker inside the chamber, where the full model index is indicated.
Does the type of freon affect the choice of starting relay?
Direct influence of the type of refrigerant (R600a or R134a) on the design of the starting relay the relay does not, since the relay works with an electrical circuit, and not with the refrigerant. However, compressors for different freons may have different starting currents and winding characteristics. Therefore, it is important to select a relay recommended specifically for your compressor model, which, in turn, is designed for a specific type of freon.