Belarusian brand refrigerators Atlant deservedly famous for their reliability, but even the highest quality equipment breaks down over time. One of the most common reasons why the unit stops freezing, and the compressor either does not start or hums for several seconds and then stops, is a breakdown of the start-up relay. This small but critical component is responsible for supplying voltage to the motor windings and protecting the motor from overloads. If you are faced with a similar problem, there is no need to panic, since replacing the relay is a procedure that can be performed independently if you have a minimum set of tools and an understanding of the principle of operation of the device.
Before taking active steps, it is necessary to carry out initial diagnostics to make sure that the problem lies in the relay, and not in the compressor itself or the wiring. Often, users mistakenly blame the motor, not knowing what exactly starting relay is the “guard” that prevents the motor from burning out during power surges or jamming of the rotor. In this article, we will analyze in detail the design of the unit, methods for checking it and a step-by-step replacement algorithm, which will allow you to save time and money on calling a technician.
Design and principle of operation of the starting relay
The starting relay is a compact device that is attached directly to the side or bottom of the compressor. Inside the plastic case there is an inductor, a movable core and contacts that close the starting winding circuit when the engine starts. As soon as the compressor rotor reaches the required speed, the current drops and the relay opens the circuit, leaving only the main winding to work. Modern models Atlant often use devices of the RT, R-3 series or newer variations with a posistor, which work on a slightly different principle, but perform the same function.
In addition to the starting function, the relay plays a role thermal protection. Inside the housing is a bimetallic element that bends when excessive heat or current overload occurs, breaking the electrical circuit and stopping the compressor. This prevents the insulation from melting and damaging the expensive motor. Understanding this mechanism is important, since sometimes the relay clicks, but does not start the motor precisely because the protection is triggered, and not because the starting mechanism itself is broken.
Structurally, the device can be electromagnetic or posistor. Electromagnetic relays, common on older models, have moving parts that wear out or stick over time. The posistor analogues found in new refrigerators do not have moving contacts in the classical sense and are considered more reliable, although they are sensitive to shock. When choosing a replacement, it is important to consider what type of device is installed in your particular case, since they are not always interchangeable without changing the connection diagram.
⚠️ Attention: The internal relay circuit may vary depending on the year of manufacture of the refrigerator. Always check the markings on the new device with the parameters indicated on the body of the old relay, especially paying attention to the diameter of the compressor shaft and the type of refrigerant.
Some users try to disassemble the relay to clean the contacts, but in most modern models the case is soldered or glued, and after opening the seal will be broken. This can lead to oxidation of the contacts and repeated failure after a short time. Therefore, the most reasonable solution is to purchase a new original or high-quality analog device, the cost of which, as a rule, is small compared to the risks of repeated repairs.
Why does the relay heat up during operation?
During normal operation, the relay may heat up, but should not be hot to the touch. Strong heating indicates poor contact, wear of the windings or operation of the compressor in overload mode, which requires immediate intervention.
Diagnostics of Atlant relay malfunctions
You can determine that it is the relay that has failed by the characteristic signs that appear in the operation of the refrigerator. The most obvious symptom is when the compressor tries to start, makes a short beep or click, and then goes silent again, and this repeats cyclically. This indicates that the starting winding does not receive an impulse to start, or the protection is instantly triggered due to a short circuit inside the relay itself. If at the same time the relay body becomes very hot or a burning smell emanates from it, the diagnosis is almost obvious.
For a more accurate diagnosis, the relay must be removed from the compressor and inspected visually. Traces of soot, melted plastic or oxidized contacts may be visible inside. However, external signs are not always eloquent, so the best way to check is to use a multimeter. By ringing the contacts in different positions, you can determine the integrity of the coil and the mobility of the core. If the coil is broken or the contacts are “stuck” in the closed state, the device must be unconditionally replaced.
It is also worth paying attention to the condition of the contacts suitable for the relay. If the wires have turned black or the insulation has melted, this indicates poor contact, which could cause overheating and failure of the relay itself. In such a situation, simply replacing the device may not solve the problem completely unless the cause of the poor contact is eliminated, for example, by replacing the terminals or stripping the wires.
- 🔍 The compressor hums for 3-5 seconds and turns off, followed by a pause before trying to start again.
- 🔥 The relay housing has traces of thermal damage and blackening or deformation of the plastic.
- 🔌 When rocking the removed relay, a knocking sound of the internal mechanism is heard, which indicates destruction of the core or coil.
- ⚡ The multimeter shows the absence of resistance on the coil or a short circuit between the contacts that should be open.
Important note that sometimes the cause of a startup failure may not be the relay itself, but turn-to-turn closure in the compressor windings. In this case, the new relay will operate and turn off again, protecting the circuit. Therefore, if after replacing the relay the situation has not changed, you should check the resistance of the motor windings. Single-phase refrigerator motors Atlant are characterized by the presence of a starting and operating winding, the resistance of which must fall within certain limits specified in the technical documentation.
Necessary tools and preparation for work
Replacing the relay with refrigerator Atlant does not require complex professional equipment, but having the right tool will greatly simplify the task and ensure the safety of the work. First of all, you will need a set of screwdrivers, including a Phillips and a flat head, as fasteners may vary between models. It would also be useful to have pliers with insulated handles for working with wires and terminals.
To diagnose and check the correct connection, you definitely need a multimeter (tester). With its help, you can verify that there is no voltage before starting work, which is a critical safety condition, and also check the integrity of the circuits after installing a new relay. If you have no experience working with electrical appliances, this tool will be your main assistant in controlling the process.
In addition to the basic tools, prepare a clean rag and possibly a contact cleaner spray to remove dust and possible oxides from the compressor terminals before installing a new device. Clean contacts are the key to reliable operation of the electrical circuit. It is also recommended to have electrical tape or heat shrink tubes on hand in case you need to restore the insulation of the wires.
| Tool | Purpose | Importance |
|---|---|---|
| Screwdrivers (set) | Removing the back panels, dismantling the compressor casing | High |
| Multimeter | Voltage check, diagnostics of relays and windings | Critical |
| Pliers | Fixing wires, working with terminals | Average |
| Knife or scalpel | Stripping wires, removing old insulation | Average |
Before starting any work Make sure that the refrigerator is completely disconnected from the electrical outlet. Don't just turn off the button, if there is one, but unplug the cord from the outlet. This will eliminate the risk of electric shock and short circuit. It is also worth allowing the compressor to cool down if it has tried to work before, as its temperature can be quite high.
☑️ Preparation for replacing the relay
Step-by-step instructions for replacing the relay
The replacement process begins with access to the compressor, which in refrigerators Atlant is usually located in the lower rear part of the case. Remove the metal panel covering the engine compartment by unscrewing the retaining screws. In some models, the panel may be held in place by latches, which requires careful handling to avoid breaking the plastic. After removing the panel, you will see the black “barrel” of the compressor, to which the desired device is attached to the side or bottom.
The relay is put directly on the compressor rod and secured with a metal bracket or plastic clip. Carefully remove the retaining element using pliers or a screwdriver and pull the relay down. Be careful not to pull sharply to avoid damaging the associated wires. At this stage, it is important to remember or photograph which wire is connected where, although in most cases the connectors have a unique shape and it is difficult to confuse them.
After removing the old relay, inspect the contact group on the compressor. If there are oxides or carbon deposits, carefully clean them with fine sandpaper or an eraser. Install the new relay into place, making sure it is seated tightly and all the way. Secure it with a bracket and connect the wires, observing the polarity and markings. After assembly, turn on the refrigerator and listen: the start-up should be quiet, without extraneous clicks or buzzing.
⚠️ Attention: Incorrect orientation of the relay during installation (for example, upside down) can lead to the mechanism not working or, conversely, not turning off, which will cause overheating and breakdown of the compressor. Install strictly according to the UP/DOWN marks.
If after replacing the relay the refrigerator works normally, replace the metal panel and tighten the screws. Do not leave the compressor open for a long time as this may cause dust and moisture to enter the electrical parts. During the first hours of operation, periodically check the temperature of the relay body - it should not heat up above 50-60 degrees.
Connection diagram and contact markings
Correct connection of the relay is a key point in the entire replacement process. On the device body there is usually a diagram or letter marking of the contacts, which indicates their purpose. Refrigerators Atlant are characterized by standard markings, where L indicates the line (phase), S or P the starting winding, and R or M — working winding. Understanding these symbols is necessary if the wires are disconnected or the markings on the old relay are not readable.
It is important to consider that in different series of relays (for example, RTK, R-3, 10.12) the location of the contacts may differ. Electromagnetic relays have more complex internal switching compared to posistor relays. When installing a universal relay (which is suitable for many models), you often have to rearrange the contacts or use the adapter blocks included in the kit. Carefully read the instructions for the new device to avoid mistakes.
Particular attention should be paid to the capacitor if it is present in the circuit. In some circuits, the starting capacitor is connected in parallel with the starting winding through a relay. If your refrigerator has a capacitor, make sure that it is in good working order and correctly connected, since its malfunction can also prevent the engine from starting even with a working relay.
Frequent errors and troubleshooting
Even if they follow the instructions, beginners can make mistakes that will lead to repeated breakdowns. One of the most common is to install a relay that is not designed for a specific compressor power. If the relay is rated for less current, it will constantly trip or burn out. Always select an analogue with identical or similar characteristics specified in the technical documentation for your refrigerator model.
Another mistake is ignoring the condition of the wires. If you put a new relay on burnt wires, the contact point will heat up again. In such cases, it is necessary to completely replace the section of wire or terminal. They also often forget to check the compressor rod itself for play, which may indicate a more serious problem with the motor that the relay will not solve.
Sometimes after replacement it seems that the refrigerator is working, but it does not gain temperature. This may be due to a freon leak or a faulty thermostat rather than the relay. The relay only starts the motor, but does not control the cooling capacity. Therefore, if the motor hums smoothly and for a long time, but there is no cold, the problem needs to be looked for elsewhere.
- 🛑 Installing the relay “upside down” leads to sticking of the contacts or inability to start.
- 🛑 Using non-original cheap analogues - the service life of such devices is often several weeks.
- 🛑 Ignoring the condition of the wires - old oxidized wires cause a voltage drop and heating.
- 🛑 Forced starting without a relay is strictly prohibited, as the motor windings may be damaged.
Is it possible to start a refrigerator without a relay?
Theoretically, you can start the engine by applying voltage directly to the starting winding, but doing this in a domestic environment is extremely dangerous and is not recommended. This requires precise knowledge of the switching time and is fraught with electric shock or breakdown of the compressor.
Why did the new relay immediately burn out?
This may indicate a short circuit in the compressor windings or a wiring fault. A power surge in the network could also be the cause. Before reinstallation, be sure to check the resistance of the motor windings.
How to distinguish an Atlant relay from relays of other brands?
Relays Atlant often have a specific body shape and are marked RT or P series. However, many modern relays are universal. The main thing is the coincidence of the diameter of the mounting hole and the electrical characteristics.
Is it necessary to change the capacitor along with the relay?
If the capacitor is swollen or has lost capacity, its replacement is mandatory. If it is visually intact and the tester shows normal capacity, there is no need to change it along with the relay, although preventive replacement is sometimes justified.