Sudden stop compressor or a characteristic clicking sound when trying to start often indicates a failure of the start-protection relay in refrigerators Pozis. This small but critical element is responsible for supplying voltage to the motor windings and protecting against overloads. If your refrigerator has stopped freezing, and the motor hums only for a few seconds before turning off, there is a high probability that the problem lies in this particular unit.
Independent replacement or diagnostics of the relay is a procedure available even to beginners, provided safety precautions and accuracy are followed. Unlike complex electronic control modules, a mechanical start relay is simple in design and located in an accessible location. Correct dismantling will allow you to inspect the contacts, check the integrity of the coil, or replace the part with a new one without calling a technician.
Before starting any work, you must completely de-energize the unit. Electrical safety is priority number one, since work is carried out in close proximity to live parts. Make sure that the plug is removed from the socket and that access to the back wall of the refrigerator is clear and well lit.
Location and types of relays in Pozis refrigerators
In most refrigerator models Pozis, including series Shif i Ryazan, the start-up protection relay is mounted directly on the compressor housing. It is located at the bottom of the rear wall of the unit, often hidden under a plastic casing or metal cover. It is accessible after removing the protective panel, which can be secured with latches or screws.
Structurally, the relay can be inductive (with a coil) or posistor. Older models were often equipped with induction devices with a copper coil and a moving core. Modern modifications are switching to posistors, which do not have moving parts, but the principle of their location and fastening remains similar. Understanding the type of device you have will help in further diagnosis.
It is important to note that the relay does not just hang on the wires, it is tightly seated on the three pins of the compressor. Mechanical locking is ensured by a tight fit and sometimes additional brackets or strips. There are usually markings on the side or top of the housing indicating compatibility with certain types of compressors and refrigerants.
⚠️ Warning: Never attempt to remove the relay while the compressor is hot. After operation, the temperature of the engine housing can reach 80-90 degrees Celsius, which can cause serious burns. Allow the equipment to cool for at least 30-40 minutes.
Required tools for dismantling
To successfully complete the task of removing the relay, you do not need a complex professional tool. The entire necessary set is usually available in the arsenal of any home craftsman. The main thing is to choose tools of the appropriate size so as not to damage the plastic fastening elements or wire insulation.
First of all, you will need a flat-head screwdriver. It is needed to release metal latches, if present, or to carefully pry off the plastic casing. In some cases, a Phillips screwdriver may be required to remove the protective cover of the compressor compartment.
It is also recommended to prepare:
- 🔦 Flashlight — for high-quality illumination of the darkened space behind the refrigerator.
- ✂️ Pliers — for careful removal of the terminal clamps, if they fit too tightly.
- 🧤 Safety gloves —to protect your hands from the sharp metal edge of the casing and possible dust.
- 📱 Smartphone with camera —to photograph the wiring diagram before disconnecting them.
☑️ Preparation for repair
Step-by-step process of removing the relay
The dismantling process begins with removing the protective cover covering the compressor group. In refrigerators Pozis it is often made of thin metal or plastic and is attached with screws or latches around the perimeter. Be careful when unscrewing the screws so as not to strip the threads, especially if the metal has already oxidized.
After removing the cover, you will see a view of the compressor with the relay attached to it. The next step is to disconnect the wires. Care is extremely important here. Connection diagram may vary depending on the model, so the photo you took earlier will become your main guide. Carefully remove the terminals from the relay contacts, slightly rocking them from side to side.
The relay itself is removed by moving down or to the side, depending on the design. It fits tightly onto the contact pins of the compressor. Do not use excessive force to avoid breaking the plastic mounting tabs or damaging the tubes. If the relay is sitting very tightly, you can gently rock it, holding the body, but not the wires.
What's inside the relay?
Inside the plastic case there is a copper coil, a movable core and contacts. In posistor models, there is a ceramic element that changes resistance when heated. Disassembling the housing is possible, but it is often easier to replace the entire assembly.
Diagnostics of the removed device
Once the relay is in your hands, you can begin its visual and technical inspection. Often the cause of the malfunction is visible to the naked eye. Carefully inspect the internal contacts: the presence of carbon deposits, melted plastic or oxides indicates overloads or sparking.
If the relay is inductive, shake it near your ear. If there is a noticeable knocking or rattling noise inside, this means that the core or contacts are loose, which is a sign of a malfunction. In good condition, the moving elements should move freely, but without unnecessary noise.
For more accurate diagnostics, you can use a multimeter:
- 🔌 Checking the coil —the winding resistance should be within normal limits (usually a few Ohms), a break indicates combustion.
- ⚡ Contact integrity —in In the normal position, the contacts should be open or closed depending on the type, ring the circuit.
- 🌡️ Checking the posistor —resistance should increase when heated, a cold posistor has low resistance.
Compatibility and markings table
When selecting a new relay or analyzing an old one, it is important to pay attention to the markings. Refrigerator manufacturers Pozis use components from various brands, such as Danfoss, Secop or domestic analogues. An incorrectly selected relay can lead to repeated breakdown or damage to the compressor.
Below is a table that helps you navigate the main types of relays found in this technology. Remember that exact compatibility is determined by engine power and refrigerant type.
| Relay type | Marking | Application | Features |
|---|---|---|---|
| Induction | RT-21, RTK-1-3 | Old Pozis models | Sensitive to mounting position |
| Pozistor | 17.913, 17.914 | Modern series | Independent of orientation |
| Combined | Danfoss 101L0011 | Imported compressors | High reliability |
| Thermal | 3.913.116 | Overheat protection | Works in tandem with a starter |
⚠️ Attention: Installing a relay that does not correspond to the compressor power may result in the engine not starting or the winding burning out. Always check the part number with the original.
Installing a new relay and checking operation
If the diagnostics showed a malfunction or you decided to replace the part preventatively, installation is performed in the reverse order. Carefully slide the new relay onto the three pins of the compressor as far as it will go. It should fit tightly and not wobble. Make sure that the marking UP (top) is located correctly, if required by the design.
Connect the wires to the contacts according to the photograph taken earlier. The terminals should snap into place with a characteristic click. Check the reliability of the connections by lightly pulling the wires - they should not jump off. Replace the protective cover of the compressor compartment and secure it.
Now you can turn on the refrigerator. Pay attention to the startup sound: it should be smooth, without buzzing or clicking. The compressor should pick up speed and operate evenly. If after 10-15 minutes of operation the relay body does not heat up to a burning state, and the refrigerator begins to freeze, the repair was successful.
Frequently asked questions (FAQ)
Is it possible to repair an old relay, or is it better to buy new?
In most cases, relay repair is not economically feasible. The cost of a new unit is low, and the quality of restoring contacts or coils at home often leaves much to be desired. It is more reliable and safer to install a new original element.
Why does the relay burn out repeatedly (constantly)?
Frequent combustion of the relay may indicate more serious problems: compressor wear (turn-to-turn short circuit), problems with the capacitor or power surges in the network. In such cases, simply replacing the relay will only give a temporary effect.
Where can you find the relay markings on a Pozis refrigerator?
The markings are applied directly to the plastic or metal body of the relay itself. To see it, it is not necessary to remove the part completely, just remove the protective cover of the compressor and illuminate it with a flashlight.
Is it dangerous to operate a refrigerator without a relay?
Yes, this is strictly prohibited. Without a start-protection relay, the compressor will not start correctly, and when trying to start, the motor winding may burn out or a short circuit in the network may occur.