Refrigerators of the brand Yuryuzan, produced during the Soviet period and in the 90s, are still actively used in many homes due to their reliability and maintainability. However, like any equipment, they are subject to wear and tear, and the most common cause of compressor failure is the failure of the starting device. The owner of the unit, faced with the fact that the motor hums, but does not start, or is completely silent, immediately asks the question about the location of the key elements of the electrical circuit.
Search start relay in models of this brand does not represent a difficult engineering task, since the design of classic single-chamber and double-chamber refrigerators "Yuryuzan" is unified. The device is always located at the bottom of the rear wall of the housing, directly on the compressor casing. To access it, you do not need to disassemble the entire refrigerator or dismantle complex components; you just need to move the unit away from the wall and provide access to the motor-compressor.
It is important to understand that before proceeding with physical intervention, it is necessary to completely de-energize the device. Handling live electrical components is strictly prohibited and may result in electric shock or damage to the electronics. In this article, we will analyze the algorithm of actions in detail, help identify the malfunction and replace the failed element.
The design and purpose of the starting relay
Starting relay in the refrigerator Yuryuzan performs a critical function: it provides a short-term voltage supply to the starting winding of the compressor motor. When the motor is turned on, the rotor is stationary, and to spin it up, a significant torque is required, which is created precisely by the starting winding. As soon as the shaft reaches the required speed (usually about 75% of the rated speed), the relay opens the starting winding circuit, and the engine continues to operate on the main winding.
In older models, relays of the RT type (Thermal Relay) were most often used. or RTP, RTK. These devices are electromechanical and do not require complex electronics. Inside the housing there is a coil connected in series to the working winding circuit, and a movable core with contacts. When starting, the current is high, the core is drawn in and closes the contacts of the starting winding. When the speed increases, the current drops, the core drops under the influence of gravity or a spring, opening the circuit.
In addition to the starting function, in many models the relay is also combined with thermal protective device. This element protects the motor windings from overheating. If the compressor cannot start for a long time or is overloaded, the bimetallic plate inside the relay heats up and opens the circuit, preventing the motor from burning out. After cooling, the contact closes again, trying to start the engine.
⚠️ Attention: There are contacts inside the relay that, when opened, can give a spark. Do not try to repair the insides of the relay if you do not have electrical skills - it is easier and safer to replace the entire assembly with a new analogue.
Understanding the operating principle helps diagnose the problem. If the relay “clicks” but the motor does not start, the compressor may be jammed or the winding may be burned out. If there is no silence or buzzing at all, the problem may be in the relay itself, which does not supply voltage, or in the thermostat. In models Yuryuzan most often there are malfunctions associated with burning contacts or sticking of the moving core.
Exact location of the relay on the compressor
To find the relay in the refrigerator Yuryuzan, you need to go to the back wall of the unit. In the lower part, usually in the center or offset to one side, there is a black metal cylinder - this is compressor. It is to it, on the output contacts (plug block), that the desired device is attached. It is a small plastic box of black or white color.
The relay is placed directly on three pins coming out of the compressor housing. Depending on the modification of the refrigerator (for example Yuryuzan-3, Yuryuzan-4 or later versions), the relay can be secured simply due to the tightness of the fit or additionally secured with a metal bracket-clamp. In some cases, a plastic cover is placed on top of the relay, protecting the contacts from dust and moisture.
Visually, the unit looks like a “growth” on the side or top of the round motor housing. Wires coming from the thermostat and the power plug are connected to it. If you see a box inserted into the connector on the motor itself, you have found what you were looking for. Markings are often stamped on the case, for example, RTK-1, RTP-1 or R-3, which indicates the type of device.
Symptoms of malfunction and initial diagnostics
Before looking for where the refrigerator relay is located Yuryuzan and changing it, you should make sure that the problem lies in this particular unit. There are several characteristic symptoms that indicate a failure of the trigger mechanism. Ignoring these signs can lead to more serious damage, even burning out the compressor.
The main symptom is a characteristic sound. The refrigerator tries to turn on: there is a click, then a motor hum, which lasts a few seconds, followed by another click and silence. After some time (from 30 seconds to several minutes), the cycle repeats. This indicates that start relay gives a pulse, but the engine does not start, and the thermal protection breaks the circuit.
Other signs of a malfunction include:
- 🔊 A loud metallic click when turned on, followed by complete silence and absence humming of the compressor.
- 🔥 Strong heating of the compressor housing when the fan is running (if there is one) or just a hot motor when the refrigerator is not working.
- ⚡ The appearance of a burning smell or melted insulation in the motor area.
- ❄️ Lack of cold in the chambers with the backlight working and the thermostat working.
It is also worth checking the condition of the contacts. If the relay is removable, it can be carefully removed and inspected. The presence of carbon deposits, oxides or melted plastic inside the case is a sure sign that the device requires replacement. In some cases, soot from sparking may be visible inside.
⚠️ Attention: If after replacing the relay the situation has not changed (the refrigerator hums and turns off), the problem may be in the compressor itself (an interturn short circuit or wedge). Further attempts to start may permanently damage the motor.
Diagnostics should be carried out carefully. If you hear a humming sound, but the compressor does not start, do not keep the refrigerator plugged in for more than 5-7 minutes. Constant attempts to start on a “jammed” rotor lead to overheating of the windings and their penetration into the housing.
Connection diagram and contact marking
To correctly replace or check the relay, you need to know the connection diagram. Refrigerators Yuryuzan most often use relays with three contacts corresponding to the three terminals on the compressor. The arrangement of the terminals on the compressor block is usually triangular: one upper and two lower (or vice versa, depending on the orientation).
The standard marking on the terminals of the compressor and relay is as follows:
- 🔹 R (Run) — working winding.
- 🔹 S (Start) — starting winding.
- 🔹 C (Common) —common wire.
In relays like RTK or RTP, the contacts are located accordingly. Inside the relay body, the starting winding is connected through a moving contact, and the working winding is connected through a coil. The thermal relay (protection) is connected in series to the operating winding circuit. When you remove the relay cover, you can see this structure: a coil, a core, a movable group of contacts and a bimetallic plate.
Below is a table of pin correspondence for common types of relays installed in Yuryuzan:
| Relay type | Pin marking | Location on block | Features |
|---|---|---|---|
| RTK-1 / RTK-2 | P, S, L (or no marking) | Upper, lower left, lower right | Vertical installation, the core moves up and down |
| RTP-1 | P, S, C | Depends on orientation | Posistor type, no moving parts |
| P-3 | Without markings | Standard triangular | Used in older models before the 80s |
It is important to observe the orientation during installation. Moving core relays (MCRs) must be installed strictly in the position in which they originally operated (usually up arrow). If you turn such a relay over, the core will not be able to return to its original position under the influence of gravity, and the starting winding will not turn off, which will lead to combustion.
Is it possible to use a different type of relay?
In emergency cases, you can replace the RTK relay with an RTP (posistor) if the seat and voltage match. Posistor relays are less sensitive to orientation in space, but require time to cool down (3-5 minutes) before restarting.
Step-by-step instructions for replacing the relay
Replacing the start relay in the refrigerator Yuryuzan - a procedure that is accessible even to a beginner, if you follow safety precautions and sequence actions. The main thing is to take your time and act carefully so as not to damage the cooling system tubes or electrical wires.
The first step is always to completely disconnect the refrigerator from the power supply. Unplug the plug from the socket. Move the refrigerator away from the wall so that you can comfortably work from behind. Remove the rear protective panel (cardboard or metal) if it blocks access to the compressor. In some models Yuryuzan the compressor is completely open.
Next follow the algorithm:
- Remove the fixing bracket, if any. It can be held on by a screw or simply snapped into place.
- Gently pull the relay in the direction opposite to the compressor. It should come off the pins. If it gets stuck, shake it slightly from side to side, but do not use excessive force.
- Disconnect the wires. In older models, the wires may go directly into the relay body or be connected with a twist/block next to each other. Remember or take a photo of which wire is connected where.
- Install a new relay. Push it onto the compressor pins as far as it will go. Make sure that it fits tightly and does not loosen.
- Connect the wires according to the diagram or photos taken earlier.
- Secure the bracket (if there was one) and install the protective cover.
☑️ Check before turning on
After installation, turn on the refrigerator. You should hear the engine click and start. If the motor hums smoothly, without jerking, and after a while the chamber begins to get colder, the replacement was successful. If the symptoms recur, it is possible that the wrong relay was selected or the problem is deeper.
⚠️ Attention: When removing the old relay, be careful with the tubes going to the compressor. They are filled with refrigerant and are under pressure. Damage to the tube will lead to freon leakage and will require expensive refilling from a specialist.
Compatibility table and selection of analogues
When buying a new relay, it is important to choose the right analogue, since there are no universal solutions for all models. Yuryuzan there are no universal solutions for all models. The compressor power and the type of starting device must match. Using an unsuitable relay can lead to rapid failure of both the new element and the compressor itself.
Main parameters for selection:
- 📏 Connection type (vertical/horizontal).
- ⚡ Rated current (indicated on the case, for example, 1.3A, 1.6A).
- 🏗️ Type of compressor (low temperature, medium temperature).
Most often in refrigerators Yuryuzan (which are analogues ZIL or Saratov those years) relays of the RTK series are used. Below is a correspondence table for selection:
| Refrigerator model | Original relay | Possible analogue | Compressor power |
|---|---|---|---|
| Yuryuzan-3 / KSh-100 | RTK-1 | RTK-1-2, RTK-1-3 | up to 120 W |
| Yuryuzan-4 / KSh-140 | RTK-2 | RTK-2-1, RTK-2-2 | up to 160 W |
| Yuryuzan-M | RTP-1 | POSISTOR 12 Ohm | up to 150 W |
| Yuryuzan-5 | RTK-3 | RTK-3-1 | up to 180 W |
If you cannot find an exact analogue, you can use universal starting relays, which are sold in spare parts stores. They often have multiple pairs of contacts and are suitable for a wide power range. However, for long and stable operation of a classic Soviet refrigerator, it is better to look for original components or components that are as close as possible in characteristics.
Common mistakes when doing your own repairs
Repairing a refrigerator yourself is saving money, but it requires care. Many owners Yuryuzan make typical mistakes that nullify all efforts or aggravate the situation. Knowing these “rake” will help you avoid repeated repairs.
The most common mistake is ignoring the orientation of the relay. As mentioned earlier, moving core relays (MCRs) are position sensitive. If you install it upside down, the mechanism will not work correctly. The compressor will hum, the starting winding will not turn off, and after a minute the thermal protection will work or the winding will burn out.
Other common errors:
- 🚫 Ignoring contact cleaning: when installing a new relay, old oxidized wires may not provide good contact, which will lead to heating and melting of the new device.
- 🚫 Forced start: some “masters” advise short-circuiting the relay contacts to start the compressor directly. This can only be done for a short-term check of the motor! Long-term operation without a relay is guaranteed to burn out the starting winding.
- 🚫 Incorrect diagnosis: replacing the relay if the thermostat is faulty. If the thermostat does not close the circuit, replacing the relay will do nothing.
It is also a mistake to use inappropriate materials for insulation or fastening. Do not use electrical tape where the terminal block should be, and do not wrap the relay with wire to the tubes - the vibration of the compressor will quickly destroy such a structure.
If after all the manipulations the refrigerator does not work, do not despair. The problem may not be with the relay. Test the thermostat by connecting its contacts directly. Check the integrity of the compressor windings with a multimeter. If the windings are intact, and the relay is working properly, but the motor does not spin, perhaps the compressor itself is jammed, and only replacing the unit or complex professional repairs will help.
Is it possible to repair an old relay and not change it?
Theoretically, it is possible if the problem is burnt contacts. The relay body (usually carbolite) is disassembled, the contacts are cleaned with a file or fine sandpaper. However, the service life of such repairs is unpredictable. In modern conditions, the price of a new relay is low, so it is more advisable to replace it than to risk the compressor.
Why does the Yuryuzan refrigerator relay get hot?
Slight heating of the relay body (up to 50-60 degrees) during operation is normal, since current passes through it. However, if the relay heats up to temperatures at which the plastic melts or a burning smell appears, this indicates a poor contact, a mismatch in the current load or a compressor malfunction (hard start).
Where to buy a relay for an old Yuryuzan refrigerator?
The original relays are no longer produced, but their analogues (RTK, RTP) are produced before until now. They can be found in spare parts stores for household appliances, at radio markets, or ordered from online stores specializing in components for refrigerators. You need to look for the markings stamped on the body of the old device.
How long does a starting relay last?
The average service life of a high-quality relay is 10-15 years or more. However, the number of on/off cycles directly affects the resource. Frequent voltage drops in the network and unstable operation of the thermostat (frequent switching on) can reduce the service life of the relay to 3-5 years.