A sudden stop in the operation of refrigeration equipment often becomes an unpleasant surprise, especially if a large stock of food is stored inside. One of the most common culprits for stopping cooling in brand models Pozis is the failure of the start-up relay. This small but critical element is responsible for starting the motor and protecting the windings from overloads. If you hear clicks, but the compressor does not start, or the motor hums and immediately turns off, most likely the problem lies in this unit.
Replacing the part yourself is a real opportunity to save on calling a technician and bring the equipment back to life in the shortest possible time. The dismantling process does not require complex specialized equipment, but it demands precision and compliance with safety precautions. In this article, we will look in detail at how to correctly identify the malfunction, what tools will be needed, and how to carefully remove the relay without damaging other system components.
Diagnostics of a faulty trigger mechanism
Before proceeding with disassembly, you need to make sure that the problem really lies in the trigger device. Symptoms may be similar to a breakdown of the compressor itself or the thermostat, so it is important to conduct an initial visual and auditory inspection. Often the malfunction manifests itself in the form of a characteristic clicking sound, repeated at certain intervals, or a complete lack of response from the unit when plugged into the network.
If, after plugging into the socket, you hear the hum of the motor, which abruptly ends with a click, this is a sure sign that starting winding does not receive the necessary impulse or the thermal protection is triggered. In some cases, heating of the compressor housing may occur when the evaporator is not working. Ignoring these signals can lead to more serious consequences, including burning out the motor windings.
⚠️ Attention: If, when you try to start, the compressor makes a loud hum and knocks out the automatic plugs in the electrical panel, immediately stop trying to start. This may indicate an interturn short circuit or jamming of the piston group, where replacing the relay will no longer help.Final confirmation of the diagnosis often requires testing the contacts with a multimeter, but initial conclusions can be drawn from external signs.
📊 How your refrigerator behaves Pozis?Buzzes and clicks, but does not freezeCompletely silent and does not turn onWorks, but often turns offA cracking noise is heard when starting upNecessary tools and measures safety
High-quality repairs are impossible without preparing the workplace and having a basic set of tools. Despite the apparent simplicity of the operation, careless actions can lead to damage to copper tubes or loss of system tightness. Therefore, before starting work, you should collect everything you need and make sure that the tools are in good working order.
The main tool will be a multimeter, which will allow you to check the continuity of the circuit and the resistance of the windings. You will also need a flathead and Phillips screwdriver to remove the back cover and clamps. Pliers with narrow jaws and, possibly, a knife for stripping contacts if oxidation is detected on them will not be superfluous.
The most important rule is to completely disconnect the device from the power supply. Even after unplugging, capacitors may retain a residual charge, so do not touch live parts with bare hands without first checking. You should work in a dry room with good lighting.
☑️ Preparation for repair
Done: 0 / 5Access to the compressor and dismantling the casing
To remove the relay, you need to gain physical access to the compressor, which models Pozis usually located in the lower rear part of the case. The process begins by removing the protective metal or plastic panel covering the motor-compressor. Fastenings may vary depending on the year of manufacture and the specific series of the refrigerator.
Carefully unscrew the screws holding the back cover and set it aside. You will have a view of the black cylindrical compressor tank, condenser grille and tube system. Carefully inspect the space around the motor: sometimes the relay is covered with additional plastic protection or secured with a clamp.
On some models, for ease of operation, you may need to temporarily remove the condensate tray if it is located directly above the compressor. Be careful not to apply excessive force to copper tubing, as it is easily deformed and may burst when bent.
Design and types of relays on Pozis refrigerators
The start-up protection relay is a compact block that is placed directly on the terminals of the compressor. In refrigerators Pozis most often there are two main types of devices: posistor (RTK, RTP series) and induction (R-1, R-2 series). Understanding the differences between them is important for correct diagnosis and replacement.
Induction relays operate based on an electromagnetic coil and a movable core that closes the contacts of the starting winding when starting. PTC models use a thermocouple, which is heated by passing current and opens the circuit after the engine starts. Externally, they may look similar, but the internal circuit and principle of operation are different.
The relay body is usually made of black plastic and is marked with the model and electrical parameters. There may be arrows on the side or bottom to indicate the correct installation position. Incorrect orientation during installation will result in the device not functioning correctly.
Relay type Principle of operation Characteristic sign of failure Compatibility Induction Electromagnetic Contact sticking, humming Old Pozis models Pozistor Thermal (posistor) No start, silence Modern models Combined Start + Protection Instant shutdown Universal analogs Thermal Bimetal plate Frequent shutdowns under load Protective block ⚠️ Attention: It is strictly forbidden to install relays of a different type or with different electrical characteristics. This can lead to combustion of the compressor in the very first minutes of operation.Step-by-step instructions: how to remove the relay
The dismantling process requires care, since plastic cases become fragile over time, and the contacts can oxidize. The first step is to remove the rear cover of the compressor, if there is one, and gain access to the motor tail. Make sure that the refrigerator is unplugged for at least 15-20 minutes.
The relay is usually simply slipped onto the three contact studs of the compressor and secured with a clamp or metal bracket. If the fixing bracket is visible, it must be carefully pressed out with a screwdriver or pliers. Do not pull the device by the wires - first release the mechanical lock.
After removing the lock, take the relay by the body and pull it down with light rocking movements from side to side. If the contacts are stuck, do not use brute force; it is better to slightly warm the case with a hairdryer or use a special lubricant for the contacts. A sharp jerk can break the ceramic insulator or damage the terminals.
Sequence of actions:1. Turn off the power.
2. Remove the rear cover of the unit.
3. Disconnect the wire connectors (if any).
4. Remove the metal retaining bracket.
5. Carefully pull the relay down from the contacts.What to do if the relay cannot be removed?
If the relay is tightly seated on the contacts and does not budge, try using a thin flathead screwdriver to carefully pry the edges of the seat. Do not pick between the contacts to avoid bending them. You can lightly tap the relay body with the handle of a screwdriver to destroy the oxides. As a last resort, if the housing is not needed, it can be carefully cut with side cutters, freeing the insides, but act in such a way as not to damage the compressor terminals.
Checking the removed device and replacing
After you have managed to remove the relay, it must be inspected for external defects. Melted plastic, soot or a burning smell clearly indicate the need for replacement. However, even a visually serviceable device may not work, so a check with a multimeter is required.
Turn the tester into resistance measurement mode. For a posistor relay, the resistance between the main contacts should be within several tens of ohms. If the device shows infinity or zero, the element is faulty. Induction relays are checked for coil closure and core mobility.
When purchasing a new part, pay attention not only to the model, but also to the installation direction, indicated by an arrow on the body. Installation upside down or sideways is unacceptable for most types of relays, since the gravitational principle of operation of the moving elements is violated.
Frequently asked questions (FAQ)
Is it possible to repair an old relay, or is only replacement necessary?
In most cases, repairing a starting relay is not economically feasible and is technically difficult. PTC resistors cannot be restored, and in induction devices it is difficult to recalibrate the spring force and core weight. It’s easier and more reliable to buy a new original or high-quality analogue.
Why does a new relay burn out after a few days?
This may indicate problems with the compressor itself, for example, difficult starting or an interturn short circuit. Also, the cause may be unstable voltage in the network or incorrect selection of an analogue for the starting current. It is necessary to diagnose the motor.
Where to find the relay markings on the Pozis refrigerator?
The markings are applied directly to the black plastic body of the device. To see it, it is not necessary to completely remove the relay, just carefully move the protective cover of the compressor and look at the side edge of the part.
Is it safe to turn on the refrigerator without a relay?
No, turning on the compressor without a start relay is strictly prohibited. This will lead to instant failure of the engine starting winding, since it is not designed for long-term operation under voltage without shutting down.